The sexual question

Each Cell bears in itself Ancestral Energy. As we have already seen, the germinal, cells are not the only ones which possess the energies of all the characters of the species. On the contrary it becomes more and more certain, from further investigation, that each cell of the body bears in itself, so to speak, all the energies of the species, as is distinctly seen in plants. But in all the cells which are not capable of germinating, these energies remain incapable of development. It results that such energies, remaining virtual, have no practical importance.

In an analogous sense we may say that all the cells of the body are hermaphrodite, as all germinal cells, for each possesses in itself the undifferentiated energies of each sex. Each spermatozoid contains all the energies of the paternal and maternal ancestry of man, and each egg those of the paternal and maternal ancestry of woman. The male and the female are only the bearers of each kind of germinal cells necessary for conjugation, and each of these bearers only differs from the others by its sexual cells and by what is called correlative sexual differences. But we must not forget that the germinal cells themselves are only differentiated at a certain period in the development of the embryo; they are thus hermaphrodite originally and only become male and female later.

New experiments made on the eggs of sea urchins and other organisms have shown that conjugation may be replaced by an external irritating agent; for example, the action of certain chemical substances is sufficient to make eggs develop by parthenogenesis which would have died without this action. An entire being has been successfully produced from an egg divided into two by means of a hair. And even from the protoplasm of the egg without its nucleus, with the aid of a spermatozoid. We must not, however, base premature hypotheses on these facts.

When a female cell, or egg, develops without fecundation (parthenogenesis) its nucleus enlarges and divides in the same manner as conjugated nuclei (mitosis).

A point of general interest is what is called the specific polyembryony of certain parasitic insects (hymenoptera of the genus Encyrtus). According to Marchal, their eggs grow and divide into a considerable number of secondary eggs, each of which gives rise to an embryo and later on a perfect insect. By shaking the eggs of certain marine animals they have been caused to divide into several eggs and thus to produce several embryos. All the individuals arising from the division of the same egg of Encyrtus are of the same sex.

Embryology.—It is not necessary to describe here in detail the different changes which the two conjugated cells pass through to become an adult man. This is the object of the science of embryology. We shall return to this in Chapter III. A few words are necessary, however, to explain the general principles.

Ovulation. The corpus luteum.—The ovaries of woman (Fig. 18) contain a considerable number of cells or ovules, although infinitely less than the number of spermatozoids contained in the testicles. From time to time some of these ovules enlarge and are surrounded by a vesicle with liquid contents, which is called the Graafian follicle. At the time of the monthly periods an egg (sometimes two) is discharged from its Graafian follicle, from one or other ovary. This phenomenon is called ovulation. The empty follicle becomes cicatrized in the ovary and is called the corpus luteum (yellow body).

The egg after its discharge arrives at the abdominal orifice of the Fallopian tube, which communicates directly with the abdominal cavity. Some authors state that the end of the tube becomes applied against the ovary by the aid of muscular movement and, so to speak, sucks in the discharged ovule, while others hold that the movements of the vibratile cilia, with which the epithelium of the tubes is furnished, suffice to draw the ovule into its cavity. Figure 18 explains this phenomenon.

Having arrived in the tube, the ovule moves very slowly in the almost capillary tube by means of the vibratile cilia and arrives in the cavity of the womb. Fecundation probably takes place most often at the entrance to the tube or in its canal; sometimes possibly in the womb. On some occasions a squad of spermatozoids advances to meet the descending egg, and numerous spermatozoids are often found in the tubes, even as far as the abdominal cavity.

Fixation of the egg. Formation of the Decidua.—After fecundation, the egg becomes attached to the mucous membrane of the cavity of the womb. This mucous membrane proliferates and becomes gradually detached from the womb to form the membrana decidua which envelops the egg or ovule. An egg fecundated and fixed in this way may keep its position and grow during the first weeks of pregnancy, by the aid of villosities covering its envelope which penetrate the wall of the womb.

The womb. The placenta. The womb or uterus is the size of a small egg flattened in one direction. It terminates below in the neck or cervix, which is prolonged into the vagina as a projection, called the vaginal portion of the uterus. The cavity of the womb is continued into the neck and opens below in the vagina by an aperture which is round in virgins and is called the external os uteri. The walls of the womb consist of a thick layer of unstriped muscle. When childbirth takes place it causes tearing which makes the external os uteri irregular and fissured. During copulation the aperture of the penis or male organ is placed nearly opposite the os uteri, which facilitates the entrance of spermatozoa into the uterus. (For the illustration of these points see Fig. 18.)

The vitellus and the membrane of the egg enlarge with the embryo and absorb by endosmosis the nutritive matter necessary for the latter, contained in the maternal blood. The womb itself enlarges at the same time as the embryo.

The fasciculus attached to the embryo is the allantois which becomes the umbilical cord. The vertebræ are already easy to recognize in this embryo. The embryo is formed from a portion of blastoderm, that is to say, from the cellular layer applied to the membranes of the egg and arising from the successive divisions of the two primary conjugated cells and their daughter cells. The embryo has the form of a spatula with the head at one end and the tail at the other. From its walls is detached a surrounding vesicle (Fig. 20) called the amnion, while another vesicle, the umbilical vesicle, grows from its ventral surface and serves, in birds, for the vitelline circulation of the egg which is detached from the mother's body.

In man, the umbilical vesicle is unimportant. In its place the circulation of the blood takes place by the aid of another vesicle, called the allantois, which arises from the intestine of the embryo, and which becomes attached to the walls of the womb in the form of a thick disk called the placenta.

The placenta is formed of dilated blood vessels which meet the maternal blood vessels, also dilated, in the uterine wall, allantois later on becomes the umbilical cord.

In the placenta the embryonic and maternal vessels without actually communicating, are placed in intimate contact, which allows nutritive matter and oxygen to pass by endosmosis from the maternal vessels to those of the embryo. Figure 21 shows a human embryo at the beginning of the fifth week of pregnancy.

Duration of pregnancy. Birth. Pregnancy lasts from conjugation, which is synonymous with conception, till birth, that is about nine months (ten lunar months of four weeks). The embryo is then ready to separate from the maternal body (Fig. 22). By the act of birth it is expelled violently, bringing with it the umbilical cord and the placenta (Fig. 23). Immediately afterward the empty womb contracts strongly and gradually recovers its former size. The sudden interruption of its communications with the maternal circulation deprives the embryo, which has suddenly become a child, of its nutritive matter and oxygen.

In order to avoid suffocation it is obliged to breathe atmospheric air immediately, for its blood becomes dark by saturation with carbonic acid, which irritates the respiratory nerve centers. The first independent act of the new-born child is, therefore, a nervous reflex determined by asphyxia, and is performed with the first cry. Soon afterward the infant begins to suck, so as not to die of hunger, while the umbilical cord, having become useless, shrivels up, and the placenta is destroyed (some animals eat it). The new-born infant is only distinguished from the embryo soon after birth by its breathing and crying.

We may, therefore, say that infancy, especially early infancy, is only a continuation of embryonic life. The transformations which the infant undergoes from birth to adult age are known to all. They take place more and more slowly, except at the relatively short period of puberty.

Formation of the sexual glands.—We must remember that at a very early embryonic period certain groups of cells are reserved to form later on the sexual glands. These cells are at first neither male nor female, but are undifferentiated; later on they become differentiated to form in certain individuals, called males, the testicles with their spermatozoa, and in others, called females, the ovaries with their eggs. On this differentiation depends the sex of the individual, and, according as it takes place in one way or the other, all the rest of the body develops with the correlative sexual characters of the corresponding sex (at first the external genital organs peculiar to each sex, then the beard in man, the breasts in woman, etc).

Castration. Correlative sexual characters.—Castration is the term applied to the extirpation of the sexual glands. When it takes place in infancy it causes a considerable change in the whole subsequent development of the body, especially in man, but also in woman. Man becomes more slender, preserves a high and infantile voice, and his sexual correlative characters develop incompletely or not at all. Eunuchs are men castrated, usually in infancy. To ensure more safety in their harems the Orientals not only remove the testicles but also the penis. Bullocks and horses are bulls and stallions castrated at an early age, and can be distinguished at first sight from normal males. Females who have undergone castration become fat and sometimes take on certain masculine characters. Male human eunuchs have a high-pitched voice, a narrow chest; they remain beardless or nearly so, and have an effeminate character, often intriguing. In both sexes there is a tendency to neurosis and degeneration. It is a mistake to qualify the peculiarities of the male eunuch in the terms of female peculiarities; there is only a relative tendency. The eunuch is no more a woman than a bullock is a cow.

The characters of castrated individuals are due only to ablation of the sexual glands themselves—the testicles in man and the ovary in woman; mutilation of other sexual organs, internal or external, such as the penis, womb, etc., produces no result of this kind. It would even appear to result from recent experiments that reimplantation of a sexual gland in any part of the body is sufficient to arrest the production of the special peculiarities of the eunuch.

All these facts, almost inexplicable hitherto, become comprehensible by the aid of the engraphia of the mnemic energies. (Vide above; Semon). The sexual glands, being of undifferentiated origin, contain the energies of both sexes. The ecphoria of one of them provokes that of its correlative characters and excludes that of the characters of the other. If ecphoria of the sexual glands is arrested by castration before it is finished, this paralyzes the predominance of that of its corresponding correlative characters and reëstablishes a kind of intermediate or undifferentiated equilibrium between the ecphorias of the correlative hereditary sexual characters of the two sexes.

On the other hand, if the sexual glands of an adult are removed, his body is not sensibly modified. The sexual functions do not cease completely, although they cannot lead to fecundation. Men castrated in adult age may cohabit with their wives; but the liquid ejaculated is not semen but only secretion from the accessory prostatic gland. Adult women after castration preserve their sexual appetite, and sometimes even their menstruation, for a certain time. They generally become fat and often suffer from nervous troubles and change in character. The ecphoria of the correlative sexual characters being complete in the adult, suppression of the sexual glands can only act on their direct functions.

In different species of animals, the correlative sexual characters of which we have spoken vary enormously; sometimes the differences are insignificant, at other times they are considerable; while we can hardly distinguish a male swallow from a female, the cock and hen, the peacock and peahen, the stag and hind are very different from each other. In man, the correlative sexual characters are very distinct, even externally. These characters may extend to all parts of the body, even to the brain and mental faculties.

In some of the lower animals, for example the ants, the sexes differ remarkably from each other and appear to belong to different zoölogical families. The eyes, the form of the head, the color, and the whole body differ so much that, when a case of pathological lateral hermaphrodism is produced (that is, when the sexual glands are male on the one side and female on the other), we can exactly determine the male or female character on each portion of the body. We thus see hermaphrodite ants with one half of the body male and the other half female—black on one side and red on the other, a large eye on one side and a small eye on the other, thirteen joints in one antenna and twelve in the other, and so on. In this case the mental faculties are sometimes female, sometimes male, according as the ecphoria of the brain is influenced by the hereditary mneme of the male or female part of the hermaphrodite sexual organs, which results in a male or female brain. I have seen hermaphrodite ants in which two parts of the thorax formed a crossed hermaphrodism; in front, male on the right and female on the left, behind female on the right and male on the left. Further; among ants which live in societies, the progressive transformation of the species, or phylogeny, has produced a third sex derived from the female sex—the worker; sometimes there is even a fourth—the warrior. In these two forms the wings are absent, but the head and brain are much larger; the sexual organs remain female, but are very small. While the large brain (pedunculated bodies of the supra-esophageal ganglion) is almost rudimentary in the male, it is well developed in the female and very large in the worker and the warrior. Among these singular animals exist pathological hermaphrodites, not only between males and females, but between males and workers, and not only lateral but mixed and crossed in all possible ways. I have seen a hermaphrodite, whose abdomen and sexual organs were almost entirely male, accomplish all the complex instinctive actions of a worker of his species (expeditions, attacks on a hostile ant heap, abduction of chrysalids), thanks to its head and brain which were of the worker type. The female itself is incapable of such complex actions. I cite these facts here as material for study, for we are only too prone in this domain to generalize prematurely and to draw too hasty conclusions. In reality, there is still a wide field for study of the greatest interest.

There are animals which are normally and physiologically hermaphrodite, for they possess in the normal state male and female sexual glands and fecundate themselves, such as the solitary worms, or in pairs such as the snails. In the latter case there is copulation, during which each animal plays the parts of both male and female.

In man and other vertebrates, hermaphrodism is always abnormal. In man it is extremely rare and nearly always very incomplete, being usually limited to the external or correlative characters.

Heredity.—It results from what we have said that every living being reproduces, more or less identically, in its specific characters, the whole life of its parents and less remote ancestors, and constitutes the continuation of life from a minute part of their bodies.

Each individual life thus repeats an entire cycle of development called ontogeny, which is peculiar to all individuals of the species. Here we must mention three fundamental points:

(1). In its principal characters, each individual is the copy of its parents or direct ancestors, with correlative sexual peculiarities which we have mentioned, and with individual variations due to the combinations of varieties by conjugation, and the alternating or unequal ecphorias of hereditary characters; that is to say paternal or maternal hereditary engrams.

(2). No individual is absolutely identical with another.

(3). On the average, each individual resembles more especially its direct ancestry and its parents, and differs more markedly from its parentage the more this is remote.

We shall see later on that the ancestral relationship of the different groups, species and varieties of animals has been fairly well fixed, and we may say that the third of the laws stated above is equally true in a wider sense. In fact the species and varieties of animals which are near related resemble each other, while the genera, families and classes are more dissimilar as their relationship is more remote. We employ here the terms resemblance, homology and difference in their profound and general sense. Certain purely external resemblances, due to phenomena of convergence, must not be considered as homologies in the sense of hereditary relationship. Thus, in the language of natural history we do not say that a bat resembles a bird, nor that a whale resembles a fish, for here the resemblances are due simply to aërial or aquatic life which produces the effects of convergence, while the internal structure shows them to be quite dissimilar organisms. Although it swims in the sea the whale is a mammal; its fins at first sight resemble those of a fish, but they are really the homologues of the four limbs of other mammals and contain the corresponding bones.

In man, we see that brothers and sisters resemble each other in a general way, but that each one is dissimilar in some respects from the others. If we compare different families with many children we find that brothers and sisters resemble each other the more their parents are alike and come from a uniform ancestry which has undergone little crossing, while the crossing of different races and human varieties results in the production of individuals which differ from each other considerably, even when they come from the same couple.

If we examine things more closely, we find that the characters of each of the offspring of the same couple present neither simple repetition nor an equal mixture of the peculiarities of the parents, but very diverse combinations of the characters of several ancestors. For instance, children may bear a striking resemblance to a paternal grandfather, a maternal grand-aunt, or a maternal great-grandmother, etc. This is called atavism. Some children resemble their father, others their mother, and others a kind of mixture of father and mother.

A closer examination reveals further very curious facts. An infant which, in its early years, strongly resembles its father, may later on resemble its mother, or inversely. Certain peculiarities of a certain ancestor appear suddenly, often at an advanced age. It is needless to say that peculiarities concerning the beard cannot appear till this has grown, and this simple fact is so characteristic that it has been called hereditary disposition. Everything may be transmitted by heredity, even to the finest shades of sentiment, intelligence and will, even to the most insignificant details of the nails, the form of the bones, etc. But the combinations of ancestral qualities vary so infinitely that it is extremely difficult to recognize them. Hereditary dispositions arise from the energy of two conjugated germs during the whole of life and till death. Old people sometimes develop peculiarities hitherto unknown in them, owing to the fact that one or more of their ancestors also presented the same phenomena at an advanced age.

Semon has clearly proved that, although forming an infinite number of combinations the engrams or hereditary energies never blend in the proper sense of the term, and in the light of his exposition the above facts are more clearly explained than they had been hitherto. The experiments of Mendel have shown in plants a certain alteration in the hereditary ecphorias of the products of dissimilar parents.

Certain parental characters, according as they are added or subtracted, may disappear during one or two generations, to reappear all the more strongly in the following generations. In short, there are a number of phenomena, the laws of which may be more clearly explained to us in the future.

To sum up, each individual inherits on the average as much from his paternal as from his maternal side, although the minute nucleus of the spermatozoid is the only agent concerned on the paternal side, while the mother provides not only the egg which is much larger, but also nutrition during the nine months of embryonic life. We can only conclude that in the egg also it is only from the part of the nucleus which conjugates with the male nucleus that arise all the inherited maternal peculiarities; that all the rest is only utilized as food; and that the nutritive blood of the mother in no way influences the inherited energies of the offspring.

This shows the capital importance of conjugation and of the substance of the conjugated nuclei, especially of their chromatin. The fact that, in certain of the lower animals, the protoplasm of the egg without nuclei may occasionally produce some phenomena of cell division, thanks to its inherited mnemic engrams, in no way alters the fundamental principle which alone occurs in man, for this vicarious action, which is moreover rudimentary, only happens when the protoplasm of the egg is not consumed by the conjugated nuclei.

Parthenogenesis is also a very interesting phenomenon in the history of our animal ancestors, but for the same reasons it has no direct interest for humanity.

If we take into consideration all the observations of which we have just spoken, which are as simple as they are irrefutably demonstrated, it is hardly possible to interpret them in any other way than by the following hypothesis:

In each sexual gland, male or female, the germinal cells which are produced by division of the cells of the embryo, reserved primarily for reproduction, differ considerably from each other in quality and contain in their infinitely small atoms very diverse and irregularly distributed energies, inherited from their different ancestors. Some contain more paternal and others more maternal energy, and among the former there are some contain, for example, more paternal grandfather and others more maternal grandmother, and so on to infinity, till it is impossible to discover the ancestral origin of the fully grown individual we are examining. The same holds good for the energies of the maternal cells.

At the time of conjugation, the qualities of the child which will result from it depend therefore on conditions of the ancestral qualities of the conjugated egg and spermatozoön. Moreover, although of the same size, the nuclei which become conjugated are evidently of unequal strength; the energies of one or the other predominate later on in the embryo, and still later in man. According to circumstances the latter will resemble more or less his paternal or maternal progenitors.

Moreover, the different organs of the body may receive their energies from different parts of the conjugated nuclei in different degrees. A person may have his father's nose and his mother's eyes, the paternal grandmother's humor and the maternal grandfather's intelligence, and all this with infinite degrees and variations, for it is only a matter of more or less accentuated averages. In my own face the two halves are distinctly different, one resembling my maternal ancestry and the other, in a lesser degree, my paternal ancestry, these points being seen distinctly in photographs taken in profile.

Each germinal cell contains the hereditary mneme of its ancestors, paternal and maternal, and the two cells united by conjugation (Fig. 17) that of the ancestors of each of them. We have spoken above of ecphorias produced according to Mendel's law and reproducing characters which have been latent during one or two generations. Darwin was the first to study this interesting fact, which shows how atavism often results from the crossing of varieties. There are several varieties of fowls which do not brood; if two of these varieties, b and c, are crossed excellent brooders are obtained. Semon assumes that in each of the non-brooding varieties the ancestral energy, a, of the primary species, is weaker than that of varieties b and c; we have then a > b, and a < c. But if b is coupled with a the product represents the value b + c + a + a. Then b and c are in equilibrium; and a being doubled becomes stronger than each of them and arrives at ecphoria in their place, which restores the faculty of brooding to the product of crossing.

De Vries has shown, in the crossing of varieties with their primary species, more or less analogous phenomena which he calls "Vicino-variations." Conjugation leads to infinite combinations and variations which the law of heredity traverses like a guiding line.

The celebrated zoölogist, Weismann, considers that the chromatin of each germinal cell contains a considerable quantity of particles each of which is capable of forming an entire organism similar to the parents; these he calls "ides." According to Weismann, each ide is subdivided into "determinants" from which each part of the body is derived, being potentially predetermined in them. According to the action of a yet unknown irritation male or female determinants develop in each individual of the animal species with separate sexes. But if the determinants are disordered, either by abnormal variations or by pathological causes, hermaphrodites or monstrosities may be produced. In animals which are normally hermaphrodite (snails, etc.), there is only one kind of sexual determinant, while in polymorphous animals (ants, etc.), there are as many as the polymorphous forms. The conception of "ides" and "determinants" is only a hypothesis to which we must not attach much value. The mnemic laws established by Semon give a much better explanation of the facts.

It has often been maintained that the qualities of higher forms of man are exhausted in a few generations, while the mass of mediocrities continually produce new genius. The fact that the descendants of distinguished men are often mediocre and that remarkable men suddenly arise from the common people, appears at first sight to support this superficial assertion. It is forgotten, however, that in a people whose average mass consists of thousands or millions of individuals, while men of higher powers are only counted by units or dozens, all this arithmetic is reduced to absurdity by the inequality of numbers, as soon as the law of heredity is understood. To make a more exact calculation, it would be necessary to compare the number of superior men who have arisen from some hundreds of the most distinguished families of a country with that of distinguished men who have arisen from some millions of the rest of the people, and then calculate the percentage. It is also necessary to take into account the means employed in the education of the individuals. If education is obligatory and gratuitous in a country, this factor will have less importance.

Another error which is committed in such cases is to neglect the influence of the maternal lineage. A common woman will lower the level of the offspring of a distinguished husband, and inversely. In his "History of Science and Scientists" Alphonse de Candolle has given irrefutable proof that the posterity of high-class men furnishes a great number proportionally of men high class in their turn, compared with that of the average population. This shows the value of the usual twaddle concerning this question. It is inconceivable that the laws of heredity should make an exception of the mental qualities of man. Moreover, the most deceptive point is the contrast of a man of genius with his children, who do not rise to his standard because they represent a combination of his ancestral energies with those of their mother. This contrast makes the children appear unfavorably, while the public has a general tendency to exaggerate the value of a great man.

The theory of the mneme throws light on this subject, by introducing a new factor in the question, that of ecphoria of the cerebral engrams of the ancestors, accumulated in the hereditary mneme.

Heredity of Acquired Characters.—While Darwin and Haeckel affirmed the possibility of the heredity of characters acquired during life by different tissues, for instance the brain, Weismann limits the possibility to everything that can modify the nucleoplasm of the germinal cells. We must first eliminate the question of the phenomena of blastophthoria, which we shall consider next, and which Weismann was, I think, the first to comprehend, without giving them the name.

On one hand we see the singular effects of castration, which we have already considered; on the other hand, an extraordinary constancy in the hereditary characters of the species. For more than three thousand six hundred years, which corresponds to about eight hundred generations, the Jews have been circumcised. Nevertheless, if a Jew ceases to circumcise his offspring the prepuce of his children grows as it did three thousand six hundred years ago, although, during the eight hundred generations in question, its absence from birth has prevented it reacting on the germinal cells of the individuals. If the engraphia of the external world could sensibly modify in a few generations the hereditary mneme of the species, it appears evident that the Jewish infants of the present day would be born without prepuce, or at least with an atrophied one.

It is on such facts, which are innumerable in natural history, that Weismann relies to repudiate absolutely the heredity of characters acquired by non-germinal organs and to attribute the development of organisms to blends and combinations due to conjugation, or crossing, as well as to natural selection, which he regards as all-powerful. Darwin well recognized the difficulty in question, and being unable to explain the facts, had recourse to the hypothesis of pangenesis, that is of small particles detached from all parts of the body and transported by the blood to the germinal cells, to transmit to them, for example, the qualities acquired by the brain during life. This hypothesis was so improbable that Darwin himself was forced to recognize it. Let us examine the facts.

On the one hand a newly born Chinese transported and brought up in France will learn French, and will show no inclination to learn or understand Chinese. This well-established fact seems in favor of Weismann and against the heredity of acquired characters. But, on the other hand, we cannot understand how the evolution of the brain and its functions takes place, without admitting that in one way or another the characters acquired by habits repeated during many generations gradually accumulate in the form of hereditary dispositions in the germinal protoplasm. It is certain that our brain has progressed since the time when our ancestors were similar to the gorilla, or even the cave man at the beginning of the quaternary age. How can this cerebral progression be explained only by selection which can only eliminate, and by crossings which by themselves can hardly raise the average? It is here that the intervention of an unknown power is necessary, something unexplained, the action of which has been lately recorded in the phenomena of mutations of de Vries.

De Vries proves that certain variations appear suddenly and without any known cause, and have a much greater tendency to be preserved than the variations obtained by crossing and selection. In my opinion the phenomena of the mneme revealed by Hering and Semon explain the apparent contradictions which have hitherto impaired the theories of heredity. Mnemic engraphy explains, by its infinitesimal and repeated action through numerous generations, how the external world may little by little transmit to the germinal cells the characters which it impresses on organisms. The eight hundred generations during which the prepuce of the Jews has been cut off have not yet sufficed for the ecphoria of the corresponding negative mnemic engraphia; while conjugation and selection modify rapidly and strongly in a few generations; a fact which is more striking and allows of direct experiment. Moreover, a positive engraphia must necessarily act more powerfully, and it seems to me that mutations must be the ecphoria of accumulated former latent engraphias.

Merrifield and Standfuss, by exposing caterpillars and chrysalids for varying periods to considerable degrees of cold and heat, have determined permanent changes in the specific characters of the butterflies which have emerged from them.

Standfuss and Fischer have also shown that, after several generations, by continuing the action of cold on the caterpillars, the variations thus produced can be preserved even after the cold has ceased to act. No doubt the cold acts on the germinal cells as on the rest of the body, but the heredity of an acquired character is thus demonstrated.

The experiments of Miss de Chauvin on salamanders (Axolotl) are still more conclusive, for we are dealing here with characters acquired through aquatic or aërial media, which can hardly act on the sexual glands. We cannot continue this subject any further and we return to the work of Semon. It is needless to say that the nature of mnemic engraphia remains itself an unknown quantity. As long as we are unable to transform inert matter into a living organism we shall remain in ignorance. But, when it is accepted with the laws of the phenomena which it produces, this unknown quantity, as Semon has shown, alone suffices to explain all the rest, and is already a great step toward the comprehension of the laws which govern life.

Blastophthoria.—By blastophthoria, or deterioration of the germ, I mean what might also be called false heredity, that is to say, the results of all direct pathogenic or disturbing action, especially that of certain intoxications, on the germinal cells, whose hereditary determinants are thus changed. Blastophthoria thus acts on germs not yet conjugated, through the medium of their bearers, and creates at their origin hereditary stigmata of all kinds, while true heredity only combines and reproduces the ancestral energies.

Blastophthoria deranges the mneme or hereditary engrams, and consequently a more or less considerable part of their ecphorias during the life of the individuals which arise from them. It is not a question here of the reproduction of the hereditary ancestral energies in the descendants (in different combinations) as is the case in the heredity which we have just studied, but, on the contrary, a question of their perturbation. However, the store of cells reserved as germinal cells in the embryo, the germ of which has been damaged by blastophthoric action, being usually also affected by the disturbing cause, it follows that the pathological change introduced by blastophthoria in the hereditary mneme is transmitted to the descendants by ordinary heredity. In this way blastophthoria deposits the first germ of most pathological degenerations by causing immediate deviation of all the determinants of the germ in the same direction.

The most typical and the commonest example of blastophthoria is that of alcoholic intoxication. The spermatozoa of alcoholics suffer like the other tissues from the toxic action of alcohol on the protoplasm. The result of this intoxication of the germs may be that the children resulting from their conjugation become idiots, epileptics, dwarfs or feeble minded. Thus it is not alcoholism or the craving for drink which is inherited. No doubt the peculiarity of badly supporting alcohol is inherited by ordinary heredity as a hereditary disposition, but it is not this which produces the alcoholic degenerations of the race. These are the result of the single blastophthoria. When, on the other hand, a man is found to be imbecile or epileptic as the result of the insobriety of his father, he preserves the tendency to transmit his mental weakness or his epilepsy to his descendants, even when he abstains completely from alcoholic drinks. In fact, the chromosomes of the spermatozoid, from which about a half of his organism has issued, have preserved the pathological derangement produced by the parental alcoholism in their hereditary mneme, and have transmitted it to the store of germinal cells of the feeble minded or the epileptic, who in his turn transmits it to his descendants. From Weismann's point of view his hereditary determinants remain pathologically deviated. All intoxications which alter the protoplasm of the germinal cells may produce blastophthoric degenerations, which continue to menace several successive generations in the form of hereditary taints.

Other deviations in the development of the germs may act in an analogous manner to blastophthoria. We have mentioned above the experiments of Merrifield and Standfuss on the caterpillars of certain butterflies. Without being really of a pathological nature, these actions of a physical agent on the hereditary energies resemble blastophthoria.

Mechanical action on the embryo may also give rise to pathological products or even mutilation. Thus, Weismann demonstrated the production of degenerate individuals in ants when certain coleoptera were introduced in their nest, the ants being fond of the secretion of the large glandular hairs of the coleoptera. The exact cause of the degeneration has not yet been found, but the fact is certain. In man, certain constitutional affections and congenital anomalies are the result of certain diseases in the procreators, which have affected the germinal cells or the embryo (for instance syphilis). As soon as the blastophthoric actions cease in the procreators, those of their descendants who live under a normal regimen have evidently a tendency to eliminate the blastophthoric organs at the end of several generations and to regenerate themselves little by little. Thanks to the power of the ancestral mneme which tends to reëstablish homophony. However, the data on this subject are insufficient. In this case homophony is represented by the normal equilibrium of the different typical or normal characters of the species.

FOOTNOTES:

CHAPTER IIToC

EVOLUTION OR DESCENT OF LIVING ORGANISMS

The theory of evolution is intimately associated with the name of Darwin, for it was he who established it in the scientific world. In reality, the idea of the transformation of organisms was put forward by Lamarck more than a century ago, but he did not sufficiently support it. The theory of evolution states that the different animal and vegetable species are not each of them specially created as such from the first, but that they are connected with each other by a real and profound relationship, and derived progressively one from another; generally from more simple forms, by engraphia and selection. Man himself is no exception to this rule, for he is closely related to the higher apes.

It is no longer possible to-day to deny the fundamental fact which we have just stated. Since Darwin, and as the result of the powerful impulse which this man of genius gave to natural science, innumerable observations and experiments have confirmed the truth of the progressive evolution of living beings. Comparative anatomy, comparative geography of plants and animals, comparative embryology, and the study of the morphology and biology of a number of recently discovered plants and animals, have built up more and more the genealogical tree, or phylogeny, of living beings, that is to say their ancestral lineage. The number of varieties and races or sub-species increases indefinitely, the more closely they are examined.

Researches on the fossil remains of species of animals and plants which have been extinct for thousands and millions of years (palæontology) have also contributed to determine the trunk of the great tree of former life. The numerous gaps which still exist between these fragmentary documents of former ages are nevertheless too considerable for continuous connections to be established in the past by the aid of fossils.

We not only know that the different forms of living beings are connected to each other by a real relationship, but we can fathom more and more deeply the degrees of this relationship, and can often prove from which group of animals a given group is descended. In many cases we can determine at which period the fauna and flora of two continents have been separated from each other, and in what manner they have been transformed, each in its own way, while still preserving the general characters which were common before their separation. The specialist can soon discover what species belong to the old geographically differentiated fauna and flora of the country, and what have been ulteriorily imported.

I record these facts for the benefit of those persons who have not yet understood that it is absolutely useless at the present day to dispute the evolution of living beings. Deceived by the divergent opinions of scientists concerning hypotheses which endeavor to explain the details of evolution, these persons confound the details with the fundamental facts of evolution.

Ontogeny. Phylogeny.—In the light of the facts of evolution, heredity takes quite a new aspect when removed from the old biblical idea of the independent creation of species. Haeckel launched into the scientific world, under the name of "fundamental biogenetic law," a theory which, without having the right to the title of an immutable dogma, explains the facts in a general way, and gives us a guiding line along the phylogenetic history of living beings. "Ontogeny," that is the history of the embryological development of each individual, always consists in a summary and fragmentary repetition of phylogeny, or the history of the ancestors of the species to which the individual belongs. This signifies that, as embryos, we repeat in an abridged form the series of types or morphological stages through which has passed the series of our animal ancestors, from the primitive cell to man. In reality this is only true in a relative way, for a considerable part of the ancestral engraphias of the embryo has disappeared without leaving any trace; also many embryos, especially those which have special conditions of existence outside the body of their mother, have acquired special complex organs and corresponding functions. Thus, the caterpillars of butterflies with their specific and generic peculiarities, hairs, horns, etc., furnish many examples of secondary acquired characters which have nothing in common with the worm, which is the ancestral type of the butterfly represented by the embryonic period when it is a caterpillar. However, many undoubted vestiges of the ancestral history are found in the embryos at different periods of their development. It is certain that insects descended from worms, and there is no doubt that the larvæ of insects, which are almost worms, represent the ontogenetic repetition of the phylogeny of insects.

It is also certain that whales, although they have whalebone instead of teeth, have descended from cetacea provided with teeth, which in their turn descended from terrestrial mammals. But we find in the embryo whale a complete denture which is of no use to it, and which disappears in the course of the embryonic period. This denture is nothing else than a phylogenetic incident in the ontogeny of the whale.

In the fins of cetacea, as in the four limbs of other mammals, we find the same bones, which are derived from the bones of the wings and legs of their bird ancestors. In birds, the same bones are the phylogenetic derivatives of the limbs of reptiles.

All these facts demonstrate with certainty the descent of animal forms, a descent which we can follow in all its details. In certain ants whose bodies show their close relationship with a slave-keeping group, but which have become the parasitic hosts of other ants, we find not only the arched mandibles, shaped for rape, but the undoubted rudiments of the slave instinct, although this instinct has, perhaps, not been exercised by them for thousands of years.

These examples suffice to show that the form and functions of a living organism, as well as its mental faculties, are derived not only from the most recent direct ancestors of this organism, but that they partly mount much higher in the genealogical tree.

Our coccyx is a vestige of the tail of animals. It is from them also that we have inherited anger and jealousy, sexual appetites, fear, cunning, etc. As long as they remain in use, the oldest inherited characters normally remain the most tenacious and are preserved the longest. When they cease to be utilized, or become useless, they still remain for a long time as rudiments before finally disappearing; for instance the vermiform appendix of the intestine and the pineal gland of the brain. These rudiments often persist for still a longer time in the embryo, as we have seen in the case of the ancestral teeth of the embryo whales. We also meet with the stumps of wings in the chrysalis of certain ants (Anergates), the males of which have lost their wings.

Natural Selection.—The artificial selection practiced by gardeners and cattle breeders led Darwin to his hypothesis of natural selection by the struggle for existence. Confirmed in his idea by the observation of tropical nature, Darwin thought he could explain the origin of living beings by natural selection. It is this hypothesis which is properly called Darwinism. But the name Darwinism has also been given to evolution as a whole, which has been the cause of endless confusion. All the mystic and narrow-minded, full of biblical prejudice, naturally profit by this confusion to attack the facts of evolution and science itself.

The Struggle for Existence.—The struggle for existence and natural selection are absolutely positive facts, which can be constantly verified by the observation of living nature as it is presented to us. All living beings eat one another or at any rate struggle against each other, plants as well as animals; and, apart from air and water, animals are almost entirely nourished by plants and other animals. It is obvious that in this perpetual struggle the less adapted and the less armed—and by arms we include the powers of reproduction, resistance to diseases and to cold, etc.—disappear, while the better adapted and the better armed persist. I confess I cannot understand the detractors of Darwin who are blind in face of these facts and hypnotized by certain conventional suggestions.

On the other hand, what always has been and still remains hypothetical is the explanation of the descent of all plants and animals by natural selection alone. We have already spoken of the mutations of de Vries, and the theory of the mneme elaborated by Semon, and need not repeat them here. Thanks to the idea of Hering, worked out by Semon, the facts are now explained in a satisfactory manner. Engraphia, produced in the organisms by the irritating agents of the external world, prepares and builds up little by little their increasing complications, while selection, by continually eliminating the unfit, directs the elaborating work of the mneme and adapts it to the surrounding local circumstances.

De Vries has objected that the variations produced by artificial and natural selections are mutable, while sudden mutations have a much more stable character. But we have just seen that these mutations themselves are evidently only the delayed ecphoria of a long ancestral engraphia accumulated.

On the other hand, the variations obtained by selection are themselves only due to more rapid ecphorias, derived from repeated conjugations in a certain direction. Plate and others have shown that they may become more and more fixed, if they are well adapted, and thus become more tenacious. There is, therefore, no contradiction between the fundamental facts, and all is simply and naturally explained by the combination of hereditary mnemic engraphia with selection.

Recent study on the transformations of living beings have shown that they do not take place in a regularly progressive manner, as Darwin at first believed, but that periods of relatively rapid transformation alternate with periods of relative arrest, both in a general way and for each particular species. We see certain species remaining almost stationary for an immense time and tending rather to disappear, while others vary enormously, showing actual transformation. The transplantation of one species to a new environment, for instance to a new continent, provokes, as has been proved, a relatively rapid transformation. It is evident that mnemic engraphia transforms organisms the more rapidly as it changes in nature itself, which is the case in the migrations we have just mentioned, and which also changes the factors of selection.

Other facts show clearly that the fauna and flora of the present world find themselves in a period of recoil with regard to their modification. In the tertiary period the fauna and flora of the world were richer than to-day; many more older species have disappeared than new ones have arisen. This fundamental fact seems due to the extremely slow cooling of the earth, and appears to be indicated by the powerful growth in tropical climates, the fauna and flora of which resemble those of the tertiary period, and, on the other hand by the relative poverty and slowness of growth in cold countries.

Conclusions.—What are the principal conclusions to which we are led by this short study of the ancestral history or phylogeny of man?

(1). The transformation or evolution of living beings is a demonstrated fact.

(2). The factors in evolution appear at first sight to be very diverse: selection, mutation, climatological, physical and chemical factors, etc.

We have seen that they may all be connected with the fundamental principle of mnemic engraphia, aided by natural selection. No doubt the nature of the mnemic engraphia of external agents in the living substance is still unknown. When we are able to connect the laws of life with the laws of inert nature, we shall only have before us a single great metaphysical mystery, that of the tendency of mundane energy to the differentiation of details and the production of complicated forms. What is important here is to know that engraphia and selection are capable of considerably modifying species in a positive or negative manner, for good or evil, improving them by good influence and good conjugations, or deteriorating them by bad selection or by blastophthoria, which causes them to degenerate. The combination of a bad selection with blastophthoric influences constitutes the great danger for humanity, and it is here that a rational sexual life should intervene.

(3). The mental faculties of animal species, as well as their physical characters, depend on their ancestral hereditary mneme. They simply represent the internal or introspective side of central activity, and the brain obeys the natural laws of the mneme in the same way as the other organs.

(4). It follows from all this that phylogeny and selection, the same as heredity properly understood, have the right to a fundamental place in the sexual question, for the germs which, after each conception, reproduce an individual are, on the one hand, bearers of the inherited energy of our ancestors, and on the other hand, that of future generations. According to the care or neglect of civilized humanity they may be transformed for good or evil, progress or recede. Unfortunately, owing to religious and other prejudices, the question of evolution is not discussed in schools. Hence, the majority of men only hear of these things by hearsay in a rough and inexact manner; so that a series of phenomena familiar to naturalists and medical men, are still dead letters for the rest of the public. This obliges me to speak further on some points of detail.

The so-called historical times, that is the times of the Chinese, Egyptians and Assyrians, which appear to us extremely remote, are from the point of view of evolution very near to us. These ancient peoples, at any rate those who were our direct ancestors, or who were closely related to them, are thus, in the language of evolution, which takes no count of time or of the number of generations, our very near relations. The generations which separate them from us and the few hundred generations between them and those of their direct ancestors, who were at the same time ours, represent a limited period from the point of view of the ethnological history of mankind.

On the other hand, if we examine the savage peoples of America, Asia, Africa and Australia, which have been specially studied since the discovery of America and some of which are actually living, and compare them with ourselves and with our ancestors of four thousand years ago, we find that they differ infinitely more from us than we differ from our ancestors, as their ethnographical and historical remains are sufficient to prove.

Among the savage peoples we find races such as the pigmies of Stanley (Akkaas), the Weddas of Ceylon, even Australians and negroes, whose whole bodily structure differs profoundly from our European race and its varieties. The profoundness and constancy of these differences clearly show that the relationship of such races to ours must be very remote. We are concerned here with veritable races or sub-species, or at least with very constant and accentuated varieties. It is true that it is difficult to unravel the almost inextricable confusion of human races; but we may be certain that the savage races and varieties remote from ours, and even certain less-remote races such as the Mongols and Malays, are, phylogenetically speaking, infinitely less related to us than the ancient Assyrians. This indicates that the ancestors which were common to us and these races must probably be looked for several thousands of generations back, even when their descendants are still living on other continents at the present day.

It is easy to explain that human races so different could develop separately in continents and under climates with a very different mode of life and conditions of development, if we reflect that at these remote periods men only had very limited modes of transport and lived in a fashion very little different from that of the anthropoid apes, so that the ethnological forms were preserved separated from each other by small distances. This fact can still be observed among the small hostile Indian or Malay tribes, who live in tropical regions and often occupy only a few square leagues. The higher civilizations of former times could not develop beyond a comparatively limited circle, as their means of transport did not allow them to venture too far. The conquest of the whole earth by modern civilization by means of the mariner's compass, firearms, steam and electricity is thus an absolutely contemporaneous event, unique in the history of the world, the origin of which hardly goes back more than four hundred years. This event has completely upset the natural internal evolution of human races, by the fact that all the lower races attacked by civilized races armed with guns and alcohol, are destined to rapid and complete destruction.

Geology has discovered in the caves of the quaternary period, human remains which are much lower in the scale of evolution and much nearer the anthropoid apes than the lowest races still living. Their brain, as shown by the cranial cavity, was still smaller. Lastly, Dubois has discovered in Java the cranium of Pithecanthropus erectus which is intermediate between that of the orang-utan and man. If more such remains are discovered the chain of transition between the apes and man will be almost complete.

Hybridity. Consanguinity.—Before concluding this chapter we must study the question of hybrids. It is important to know to what point fecundity and descent are influenced by the degree of relationship between the two procreators. Conjugation probably arises from the general necessity of organisms to reënforce their race by variety. Consanguinity perpetuated is harmful to the species, in the same way as parthenogenesis, or indefinite reproduction by fission or budding. It produces enfeeblement and degeneration of the race, and leads to extinction by causing sterility.

By consanguinity is meant continued sexual union between near relatives. It is easy to understand that the conjugation of two germs derived from brothers and sisters or from a father and his daughter approaches parthenogenesis from the point of view of the mixing of hereditary energies. We shall see later on that nearly all peoples have a certain repugnance to consanguineous marriages. Among animals, natural selection eliminates too consanguineous products.

On the other hand, sexual union between different species, however little removed, gives no products. Near species may produce hybrids between themselves, but these hybrids are as a rule sterile or nearly so, and are incapable of perpetuating their type, which reverts rapidly to one of the primitive species.

It has been recently demonstrated that the incapacity of two species of animals to produce hybrids is intimately connected with the reciprocal toxicity of their blood. When the blood of one species is injected into the veins of another the production of hybrids is possible between them, at least as far as has been observed. It is curious to note that the blood of the anthropoid apes is not toxic for man, although these animals are very different from us, and hybrids have not yet been produced. This fact helps us to understand how it is that the differences which exist between the different human races do not prevent the production of hybrids between any two of them. In spite of this we may state, without risk of error, that the most dissimilar human races give a bad quality of hybrids, which have little chance of forming a viable mongrel race. We have not sufficient information on this point concerning the lowest human races, such as the pigmies and Weddas. On the other hand, mulattoes (hybrids between negroes and whites) constitute a race of very bad quality and hardly viable, while the hybrids between Indians and whites are much more resistant and of relatively better quality.

In this question, the middle course appears without any doubt the true one. Unions between near races and varieties, or at least between individuals of the same race or variety whose relationship is old, are certainly the best. We readily grant that the homogeneity of a race has the advantage of fixing its peculiarities in a more durable and characteristic fashion; but many inconveniences counterbalance this advantage. If we one day, by wise selection and by eliminating all sources of blastophthoria obtain a superior quality of human germs, it is possible that in the remote future, consanguinity, provided it is not exaggerated may lose its dangers.