FOOTNOTES:
[1] This is true if a strictly logical treatment of the subject is held to. As a matter of fact, it is often of advantage to begin with, or at least to take up from the beginning in connection with the indoor work, some field-work, such as the collecting and classifying of insects and the observation of their metamorphosis. As most schools begin work in the fall, advantage must be taken of the favorable opportunities for field-work at the beginning of the year. These opportunities are of course much less favorable in the winter.
[2] The classification of animals used in this book is that adopted in Parker and Haswell's "Text-book of Zoology" (2 vols., 1897, Macmillan Co.). Exception is made in the case of the worms, which are considered as a single branch, Vermes, instead of as several distinct branches.
[3] Zoology is formed from two Greek words: zoon, meaning animal, and logos, meaning discourse.
[4] The lesser group called variety, or subspecies, we may leave out of consideration for the present.
[5] Some species of animals are not represented by male individuals: and in some all the individuals are hermaphrodites, as explained in chapter XIV.
[6] Each of these higher groups has a proper name composed of a single word. In the case of no group except the species is a name-word ever duplicated. Each genus, family, order, or higher group has a name-word peculiar to it, and belonging to it alone.
[7] In some Protozoa a number of similar cells temporarily unite to form a colony, but each cell may still be regarded as an individual animal.
[8] The author recognizes the untenability of the group Vermes as a group co-ordinate with the other branches of the animal kingdom, and that "Vermes" has been discarded in modern text-books. But because of the very scant consideration which can be given the various kinds of worm-like animals the course of the older text-books will be followed, and all of the worm-like animals, as far as referred to in this book, be considered under the group name Vermes.
[9] There are in many forms a few internal projections from the exterior cuticle which act as internal skeletal pieces.
[10] The labrum differs from the other mouth-parts in not being composed of a pair of body appendages; it is simply a fold or flap of the skin of the head.
[11] A Text-book of Zoology, Parker & Haswell, 1897.
[12] The Cambridge Natural History, vol. V, 1895, vol. VI, 1899.
[13] A Manual for the Study of Insects, J. H. and A. B. Comstock, 1897.
[14] It has been shown by experiment that the winged individuals, which are able to leave the old food-plant and scatter over new plants, do not appear until the food-supply begins to run short. At the insectary of Cornell University ninety-four successive generations of wingless individuals were bred, by taking care to provide a constantly abundant supply of food. This experiment was continued for more than four years.
[15] The animals included by some zoologists in the single class Pisces, are held by other zoologists to constitute three distinct classes, thus making a subdivision of the branch into ten classes.
[16] The author wishes to call the attention of teacher and student to the plan (referred to in the Preface, page v) adopted in writing the directions for the dissections. The sequence of the references to the various organs depends on the actual course of the dissection, and not upon the association of organs in systems. And the directions are so much condensed that they are hardly more than a means of orienting the student, leaving him to work out independently, or by the aid of more detailed accounts (sometimes specifically referred to), the details of the dissection.
[17] By many zoologists the lizards and snakes are held to form two distinct orders, Lacertilia and Ophidia.
[18] One of the most unfortunate and conspicuous examples of this slaughter is the partial extermination of the song-birds of Japan in the interests of European milliners. To meet their demands the country people used birdlime throughout the woods with disastrous effectiveness, as shown in the present exceeding scarcity of birds and the abundance of insect pests.
[19] Oysters are hermaphroditic, each individual producing both sperm- and egg-cells.
[20] Jordan and Kellogg's "Animal Life," 1900, p. 274.
[21] The following directions for making skins of mammals were written for this book by Mr. W. K. Fisher of Stanford University, an experienced collector.
Transcriber's Notes:
- Obvious punctuation and spelling errors have been fixed throughout.
- Inconsistent hyphenation has been left as in the original text.
- There is no figure 27, the original text goes from figure 26 to 28, left as in the original text.
- Page 245: There is no closing parenthesis for the sentence starting "(Where the typical...".