[1] In the present paper frequent references will be made to the writings of Harvey, Galen, Aristotle, and Hippocrates. Citations from these authors will be made from the following editions:—

References to Harvey's finished writings will be made to two editions, viz.: The Works of William Harvey, translated from the Latin with a life of the author by R. Willis, M.D., London, 1847, printed for the Sydenham Society, which will here be designated as "Syd."; and Guilielmi Harveii Opera Omnia: A Collegio Medicorum Londinensi Edita: 1766, which will be designated as "Op. Omn." In the preparation of the text the present writer has used these two editions and also the first editions of Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus, Frankfort, 1628, and Exercitationes de Generatione Animalium, London, 1651. Willis's translation of passages has been revised, often freely, where the writer has judged this desirable; and sometimes the revision amounts to a fresh translation. References to Harvey's lecture notes will be made to Prelectiones Anatomiæ Universalis by William Harvey, edited with an autotype reproduction of the original by a committee of the Royal College of Physicians, London, 1886.

References to Galen's writings will be made to two editions, viz.: Claudii Galeni Opera Omnia. Editionem curavit C. G. Kühn, Leipsic, 1821-1833, which will be designated by the letters "Kn."; and Œuvres Anatomiques, Physiologíques et Medicáles de Galien, Traduites avec Notes par C. Daremberg, Paris, 1854-1856, which will be cited as "Dar." The former is the recognized working edition of the Greek text of Galen; this is accompanied by a Latin translation, to which is appended a serviceable Latin index. By the pages of this edition the Greek text of Galen is commonly cited. None of the treatises of Galen has been translated into English. Some of those most interesting to physiologists may be read in the above French translation of Daremberg. A critical edition of the Greek text of Galen's treatise On the Doctrines of Hippocrates and Plato, Claudii Galeni de Placitis Hippocratis et Platonis, with an amended Latin translation by Johannes Müller, was published by Teubner, Leipsic, 1874; it will here be cited as "Mül."

References to Aristotle's writings will be made to Aristotelis Opera: Edidit Academia Regia Borussica, Berlin, 1831-1870, which is the commonly cited Greek text. Pages and lines of this edition will always be found in the margin of a modern edition or translation. The following works of Aristotle will be referred to in this paper:—

The Psychology and its appendices, viz.: the so-called "Lesser Works on Natural Things (Parva Naturalia)." English translation by W. A. Hammond, New York, 1902. The two last treatises of the Parva Naturalia have also been translated by W. Ogle, M.D., London, 1897.

The History of Animals. English translation by R. Creswell. Bohn's Classical Library. London, 1878.

On the Parts of Animals. English translation by W. Ogle, M.D., London, 1882.

On the Generation of Animals. There is no English translation. An excellent German translation, with the Greek text, is that by Aubert and Wimmer, Leipsic, 1860.

Physics. There is no English translation; Greek text and German translation by C. Prantl, Leipsic, 1854.

On Heaven: On Generation and Corruption (In the Universe at Large). There is no English translation; Greek text and German translation by C. Prantl, Leipsic, 1857.

Meteorology. There is no English translation; French translation by J. B. St. Hilaire, Paris, 1863.

Besides the foregoing, other treatises by Aristotle may be referred to or cited briefly.

References to the Hippocratic writings will be made to Œuvres Complètes d'Hippocrate, traduction nouvelle, par É. Littré, Paris, 1839-1861, which will be designated as "Lit." This is the standard working edition of the Greek text of the Hippocratic collection, and is the one now usually cited. The accompanying French translation is complete. There is a translation into English of some of the treatises, but it cannot be recommended. A new version of the Greek text is now in slow course of publication by Teubner of Leipsic.

[2] John Aubrey: 'Brief Lives,' Chiefly of Contemporaries, etc. Edited from the Author's Mss. by Andrew Clark; 1898, Vol. I, 300.

[3] Harvey: On Generation, Preface, Syd. 152, l. 34 to 153, l. 4; Op. Omn. 168, l. 22-26.

[4] Galen: Is Blood Naturally Contained in the Arteries? Kn. Vol. IV, 703-736.

[5] Harvey: On Conception, Syd. 575, l. 9-12; Op. Omn. 592, l. 8-11.

[6] Harvey: Letter to Hofmann, Syd. 595, l. 6-15; Op. Omn. 635, l. 10-17.

[7] Harvey: Letter to Hofmann, Syd. 596, l. 3-7; Op. Omn. 636, l. 1-4.

[8] Harvey: Exercise to Riolanus, II, Syd. 122, l. 31 to 123, l. 1; Op. Omn. 122, l. 16-21.

[9] Harvey: On the Motion, etc., VIII, Syd. 47, l. 29-33; Op. Omn. 49, l. 28-30.

[10] Harvey: On the Motion, etc., IX, Syd. 48, l. 10-14; Op. Omn. 50, l. 8-11.

[11] Plato: Timæus, 70a and b; 77c to 78a; 78e to 79a.

Aristotle: On the Parts of Animals, 668a, 4 to b, 6.

Galen: On the Natural Faculties, Kn. Vol. II, 210-212; Dar. Vol. II, 318.

[12] Aristotle: On Sleep and Waking, 456a, 30 to b, 5.

Galen: On the Use of the Parts, etc., Kn. Vol. III, 269-270; Dar. Vol. I, 280-282.

[13] Galen: On the Natural Faculties, Kn. Vol. II, 186-189; Dar. Vol. II, 306-307.

[14] Harvey: On the Motion, etc., Syd. 72, l. 24 to 73, l. 12; Op. Omn. 73, l. 26 to 74, l. 15.

[15] Harvey: On the Motion, etc., Syd. 75, l. 9-22; Op. Omn. 76, l. 15-25.

[16] Joannes Riolanus, Filius: Encheiridium Anatomicum et Pathologicum, etc., Paris, 1648, 298, l. 1-4. Harvey's quotation does complete justice to the sense, but is by no means accurate verbally.

[17] Harvey: Exercise to Riolanus, I, Syd. 95, l. 4-21; Op. Omn. 97, l. 6-23.

[18] Aselli: De Lactibus, sive Lacteis Venis, etc. Milan, 1627.

[19] John Aubrey: Brief Lives, etc., 1898, Vol. I, 302.

[20] Harvey's venous artery and arterial vein correspond respectively to the pulmonary vein and the pulmonary artery of our nomenclature.

[21] Harvey: On the Motion, etc., VI, Syd. 39, l. 29 to 40, l. 15; Op. Omn. 41, l. 20 to 42, l. 10.

[22] Compare Aristotle: History of Animals, 511b, 10-24.

[23] Harvey: On the Motion, etc., XVII, Syd. 85, l. 17-25; Op. Omn. 87, l. 5-12.

[24] Aristotle: On Youth and Old Age, On Life and Death, 469b, 6-20.

[25] Aristotle: On Respiration, 473a, 8-10.

[26] Aristotle: On the Generation of Animals, 732a, 18-20.

[27] Aristotle: On Youth and Old Age, On Life and Death, 469a, 28 to 470a, 18. On Respiration, 474a, 25 to b, 24; 478a, 26 to b, 21; 480a, 18 to b, 20.

[28] Aristotle: On Respiration, 478a, 21-30.

[29] διὰ τὴν σύναψιν.

[30] Aristotle: History of Animals, 496a, 27-32.

[31] Hippocrates: On the Heart, Lit. Vol. IX, 86 and 90-92.

[32] Hippocrates: On the Heart, Lit. Vol. IX, 86-88.

[33] Galen: On the Use of Respiration, Kn. Vol. IV, 487-493.

[34] ποιότητος.

[35] Galen: Is Blood Naturally Contained in the Arteries? Kn. Vol. IV, 724-725.

[36] Galen: On the Use of Respiration, Kn. Vol. IV, 510.

[37] Galen: On the Use of the Parts, etc., Kn. Vol. III, 412; Dar. Vol. I, 381.

[38] Galen: On the Use of the Pulse, Kn. Vol. V, 149-180.

[39] Harvey: On the Motion, etc., Preface, Syd. 9-14; Op. Omn. 9-14.

[40] Galen: On the Use of the Parts, etc., Kn. Vol. III, 636-656; Dar. Vol. I, 541-552.

[41] Harvey: Prelectiones, 86 right.

[42] Compare Hippocrates: On Flatus, Lit. Vol. VI, 96.

[43] Harvey: Prelectiones, 86 right.

[44] Galen: On the Use of Respiration, Kn. Vol. IV, 470-471.

[45] Harvey: Prelectiones, 86 right.

[46] Aristotle: On Respiration, 473a, 15 to 474a, 24. Hippocrates: On the Sacred Disease, Lit. Vol. VI, 368 and 372.

[47] Hippocrates: On the Sacred Disease, Lit. Vol. VI, 368.

[48] Passages which justify the statements here made are among those cited in note 140.

[49] Galen: Is Blood Naturally Contained in the Arteries? Kn. Vol. IV, 703-736.

[50] Galen: On the Use of the Parts, etc., Kn. Vol. III, 541-542; Dar. Vol. I, 476.

[51] Plato: Timæus, 69c-d. Archer-Hind's Edition, 254, l. 13 to 256, l. 6.

[52] Aristotle: On Soul, 412a, 1 to 415a, 13.

[53] Galen: On the Doctrines of Hippocrates and Plato, Kn. Vol. V, 608.

[54] Galen: On the Use of the Parts, etc., Kn. Vol. III, 696-703; Dar. Vol. I, 575-579. See also Rapp: "Ueber das Wundernetz," Meckel's Archiv für Anatomie und Physiologie, 1827, 1-13.

[55] Galen: On Methods of Treatment, Kn. Vol. X, 839-840.

[56] On the subject of the spirits the following passages of Galen's works should be consulted, viz.:—On the Natural Faculties, Kn. Vol. II, 204, l. 11 to 206, l. 13; Dar. Vol. II, 315, l. 7 to 316, l. 14; Kn. Vol. II, 214, l. 9-16; Dar. Vol. II, 320, l. 2-9. On the Organ of Smell, Kn. Vol. II, 857-886. On the Use of the Parts of the Human Body, Book VI: Kn. Vol. III, 412, l. 6-12; Dar. Vol. I, 381, l. 4-9; Kn. Vol. III, 487, l. 3 to 488, l. 13; Dar. Vol. I, 438, l. 1 to 439, l. 9; Kn. Vol. III, 490, l. 14 to 492, l. 8; Dar. Vol. I, 440, l. 24 to 441, l. 16; Kn. Vol. III, 496, l. 5-16; Dar. Vol. I, 444, l. 6-19. Book VII: Kn. Vol. III, 536-544; Dar. Vol. I, 472-477; Kn. Vol. III, 544-549; Dar. Vol. I, 477-480. Book VIII: Kn. Vol. III, 636-651; Dar. Vol. I, 541-550; Kn. Vol. III, 651-656; Dar. Vol. I, 550-552; Kn. Vol. III, 663; Dar. Vol. I, 557; Kn. Vol. III, 672-673; Dar. Vol. I, 563. Book IX: Kn. Vol. III, 684-691; Dar. Vol. I, 569-572; Kn. Vol. III, 696-703; Dar. Vol. I, 575-579; Kn. Vol. III, 750-751; Dar. Vol. I, 602-603. Book XIV: Kn. Vol. IV, 183, l. 7-10; Dar. Vol. II, 114, l. 23-25. Book XVI: Kn. Vol. IV, 323, l. 2-18; Dar. Vol. II, 189, l. 3-21; Kn. Vol. IV, 333, l. 18 to 335, l. 10; Dar. Vol. II, 195, l. 6-36. Book XVII: Kn. Vol. IV, 349, l. 5-14; Dar. Vol. II, 202, l. 30-38. On the Causes of Respiration, Kn. Vol. IV, 465-469. On the Use of Respiration, Kn. Vol. IV, 470-511. Is Blood Naturally Contained in the Arteries? Kn. Vol. IV, 703-736. On the Use of the Pulse, Kn. Vol. V, 149-180. On the Doctrines of Hippocrates and Plato, Book II: Kn. Vol. V, 281, l. 3-15; Mül. 245, l. 10 to 246, l. 6. Book III: Kn. Vol. V, 355, l. 18 to 356, l. 11; Mül. 325, l. 16 to 326, l. 9. Book VI: Kn. Vol. V, 524, l. 12 to 525, l. 16; Mül. 512, l. 3 to 513, l. 8; Kn. Vol. V, 571, l. 12 to 573, l. 2; Mül. 563, l. 12 to 566, l. 2. Book VII: Kn. Vol. V, 600-611; Mül. 596-608; Kn. Vol. V, 611-617; Mül. 608-615; Kn. Vol. V, 628, l. 8-15; Mül. 626, l. 8-15; Kn. Vol. V, 641, l. 14 to 642, l. 6; Mül. 641, l. 13 to 642, l. 6. Book VIII: Kn. Vol. V, 707, l. 17 to 710, l. 15; Mül. 714, l. 14 to 718, l. 2. On Methods of Treatment, Book IX: Kn. Vol. X, 635, l. 6 to 636, l. 12. Book XII: Kn. Vol. X, 839, l. 10 to 840, l. 3.

[57] Harvey: Prelectiones, 83 right.

[58] Harvey: Prelectiones, 85 left.

[59] Harvey: Prelectiones, 83 right and 85 left.

[60] Compare R. Columbus: De Re Anatomica. Venice, 1559, 223-224.

[61] Harvey: Prelectiones, 85 left. The last line of page 85 left, as deciphered and printed, reads as follows: "Galenus 7 & p. 8°." It should read, however, "Galenus 7 u.p. 8°." That this is Harvey's brief reference to Galeni Lib. 7, De Usu Partium, Cap. 8, is proved by the text of the Galenic passage thus referred to, viz.: Galen: On the Use of the Parts, etc., Kn. Vol. III, 539-540, Dar. Vol. I, 475.

[62] As no other claimant than Columbus to be the discoverer of the pulmonary transit of the blood was known to Harvey, the question whether Columbus was the true discoverer, or possibly owed the basis of his doctrine to the unfortunate Michael Servetus, need not here be discussed.

[63] Vesalius: De Humani Corporis Fabrica, Basel, 1543; Lib. VI, Cap. II, 589, l. 9-24. Vesalius: Opera Omnia Anatomica et Chirurgica, Leyden, 1725, Tom. I, De Hum. Corp. Fabr. Lib. VI, Cap. 11, 511, l. 11-23; Cap. 15, 519, l. 42-54. Columbus: De Re Anatomica, Lib. VII, 177, l. 17-24.

[64] Aristotle: On the Parts of Animals, 649b, 19-27.

[65] Harvey: Prelectiones, 85 right. Compare closely similar passages in Harvey: On the Motion, etc., Introduction, Syd. 12, l. 9-15; Op. Omn. 12, l. 10-17. Exercise to Riolanus, II, Syd. 116, l. 26-33; Op. Omn. 116, l. 15-20. On Generation, LXXI, Syd. 504, l. 22-28; Op. Omn. 525, l. 23-29.

[66] The decipherer of Harvey's Ms. notes reads "generatur."

[67] Harvey: On the Motion, etc., Introduction, Syd. 18, l. 16-21; Op. Omn. 18, l. 17-21.

[68] Compare Aristotle: On Respiration, 470b, 28 to 471b, 29.

[69] Harvey: Prelectiones, 86 left.

[70] Harvey: On the Motion, etc., Introduction, Syd. 16, l. 23-27; Op. Omn. 16, l. 21-26.

[71] Harvey: On the Motion, etc., Introduction, Syd. 16, l. 28-39; Op. Omn. 16, l. 27 to 17, l. 4.

[72] πνεῦμα.

[73] Aristotle: History of Animals: 496a, 27-32.

[74] Columbus: De Re Anatomica, Lib. VII, 178-180; Lib. XI, 223-224; Lib. XIV, 259 and 261.

[75] Harvey: Prelectiones, 86 left.

[76] Galen: On the Doctrines of Hippocrates and Plato, Kn. Vol. V, 611-617; Mül. 608-615.

[77] Harvey: Prelectiones, 94 right: "puto: spiritus Nervis non progredi sed Irradiatos et actus fieri unde sensus et motus ut lumen in aere: forsan ut fluxus et refluxus Maris," etc.

[78] Harvey: Exercise to Riolanus, II, Syd. 118, l. 9-14; Op. Omn. 117, l. 29-32.

[79] Harvey: Prelectiones, 86 left.

[80] Columbus: De Re Anatomica, Lib. VI, 166-167; Lib. VII, 177-178; Lib. XI, 22.

[81] Harvey: Exercise to Riolanus, I, Syd. 98, l. 16-23; Op. Omn. 100, l. 21-28.

[82] Harvey: Exercise to Riolanus, II, Syd. 113-121; Op. Omn. 113-121. On Generation, LXXI, Syd. 501-512; Op. Omn. 523-534.

[83] Harvey: On Generation, LXXI, Syd. 502, l. 33-37; Op. Omn. 524, l. 5-7.

[84] Harvey: On Generation, LXXI, Syd. 504, l. 22-31; Op. Omn. 525, l. 25-32.

[85] Harvey: Exercise to Riolanus, II, Syd. 118, l. 32-38; Op. Omn. 118, l. 16-19.

[86] Harvey: Exercise to Riolanus, II, Syd. 119, l. 3-5 and l. 10-17; Op. Omn. 118, l. 26-28 and 118, l. 30 to 119, l. 4.

[87] Harvey: Prelectiones, 86 right.

[88] Harvey: Exercise to Riolanus, II, Syd. 113, l. 28 to 114, l. 19 and 117, l. 35 to 118, l. 9; Op. Omn. 113, l. 22 to 114, l. 14 and 117, l. 19-29.

[89] Harvey: On Generation, LII, Syd. 388, l. 31-32; Op. Omn. 405. l. 14-15.

[90] Harvey: On Generation, LII, Syd. 386, l. 11-12; Op. Omn. 402, l. 24-26.

[91] Harvey: Prelectiones, 87 left.

[92] Galen: On the Doctrines of Hippocrates and Plato, Kn. Vol. V, 571-572; Mül. 563, l. 12 to 565, l. 9.

[93] Harvey: Exercise to Riolanus, II, Syd. 114, l. 26-29; Op. Omn. 114, l. 19-21.

[94] Harvey: Exercise to Riolanus, II, Syd. 114, l. 37-40; Op. Omn. 114, l. 28-31.

[95] Harvey: Exercise to Riolanus, II, Syd. 115, l. 18-21; Op. Omn. 115, l. 12-14.

[96] Harvey: Exercise to Riolanus, II, Syd. 136, l. 19-21; Op. Omn. 136, l. 12-13.

[97] Harvey: On the Motion, etc., XVII, Syd. 77, l. 24-29; Op. Omn. 79, l. 5-9.

[98] See J. C. Dalton: Doctrines of the Circulation, Philadelphia, 1884, 127-128.

[99] Columbus: De Re Anatomica, Lib. XI, 223, l. 11 to 224, l. 8.

[100] Galen: On the Use of the Parts, etc., Kn. Vol. III, 451-452; Dar. Vol. I, 412, l. 5-8.

[101] Harvey: Letter to Slegel, Syd. 597, l. 14-23; Op. Omn. 613, l. 19-27.

[102] Harvey: On Parturition, Syd. 530, l. 3-10 and l. 25-36; Op. Omn. 549, l. 22-27 and 550 l. 11-20.

[103] Harvey: Letter to Hofmann, Syd. 596, l. 3-7; Op. Omn. 636, l. 1-4.

[104] Harvey: Exercise to Riolanus, II, Syd. 123, l. 15-18; Op. Omn. 122, l. 31 to 123, l. 1.

[105] Harvey: On the Motion, etc., IX, Syd. 48, l. 21 to 50, l. 36; Op. Omn. 50, l. 17 to 52, l. 23.

[106] Harvey: Prelectiones, 80 right.

[107] Hippocrates: On Wounds, Lit. Vol. VI, 430.

[108] Hippocrates: Epidemics, Lit. Vol. V, 114-116. Compare Galen's Third Commentary on Epidemics, Kn. Vol. XVII, A., 433, l. 14 to 436, l. 2.

[109] Harvey: Prelectiones, 79 right.

[110] Harvey: Exercise to Riolanus, II, Syd. 140, l. 30-39; Op. Omn. 140, l. 23-31.

[111] Harvey: Exercise to Riolanus, I, Syd. 98, l. 9-23; Op. Omn. 100, l. 14-28.

[112] Hippocrates: On the Heart, Lit. Vol. IX, 84, l. 11-12.

[113] Aristotle: On Youth and Old Age, etc., 469b, 6-20.

[114] Aristotle: On the Parts of Animals, 670a, 23-26.

[115] Galen: On the Use of Respiration, Kn. Vol. IV, 505, l. 15 to 506, l. 5.

[116] Harvey: On the Motion, etc., VIII, Syd. 46, l. 34 to 47, l. 16; Op. Omn. 49, l. 3-19.

[117] Aristotle: On Respiration; On the Parts of Animals, Books II and III; and elsewhere. This reference is by Harvey himself.

[118] Aristotle: On the Parts of Animals, Book II. This reference is by Harvey himself.

[119] Harvey: On the Motion, etc., XV, Syd. 68, l. 19 to 69, l. 17; Op. Omn. 69, l. 22 to 70, l. 18.

[120] Harvey: On the Motion, etc., XV, Syd. 70, l. 17-25; Op. Omn. 71, l. 22-29.

[121] Harvey: On the Motion, etc., XVI, Syd. 72, l. 8-11; Op. Omn. 73, l. 13-16.

[122] Harvey: On the Motion, etc., XVII, Syd. 83, l. 9-27; Op. Omn. 84, l. 31 to 85, l. 14.

[123] Hippocrates: On the Nature of the Child, Lit. Vol. VII, 530, l. 3-19.

[124] Aristotle: History of Animals, 561a, 4 to 562b, 2.

[125] Harvey: On the Motion, etc., XVII, Syd. 76, l. 3-10; Op. Omn. 77, l. 14-20. On Generation, XVII, Syd. 235, l. 21-26; Op. Omn. 249, l. 9-13.

[126] Harvey: On the Motion, etc., IV, Syd. 30, l. 14-18 and 30, l. 31 to 31, l. 4; Op. Omn. 32, l. 8-10 and 32, l. 22-30.

[127] Aristotle: On the Parts of Animals, 666a, 8-13.

[128] Principium.

[129] Harvey: On the Motion, etc., XVI, Syd. 74, l. 4-15; Op. Omn. 75, l. 9-19.

[130] It would be natural to conjecture that this Aristotelian slighting of spirits derived from the air, taken in connection with Aristotle's exaltation of the vital innate heat, may have had much weight with Harvey, who, although he used the word "spirits" freely, insisted that the blood and the spirits are one. But in this matter the Aristotelian precedent cannot have had the same force for Harvey that it would have for us, because he believed Aristotle to be the author of two treatises in which the spirits are expressly treated, not only as entities, but as entities of great physiological importance, though their relations with the outer air are neglected in one of the treatises and quite obscurely dealt with in the other. (See Harvey: On the Motion, etc., IV, Syd. 29, l. 16-25; Op. Omn. 31, l. 8-16. Do., VI, Syd. 38, l. 7-12; Op. Omn. 40, l. 2-5.) Indeed, Harvey in one of his references to Aristotle directly affirmed that the philosopher had believed in "motor spirits" within the animal body. (See Harvey: On the Motion, etc., XVII, Syd. 81, l. 8-12; Op. Omn. 82, l. 31 to 83, l. 3. Compare [Pseudo-] Aristotle: On Spirits, 485a, 5-8; and the Latin translation of the same "by an unknown interpreter," 249b, 13-18.) The two treatises in question are entitled, respectively, "On the Motion of Animals" and "On Spirits," and have been attributed to Aristotle and habitually printed among his works, both before and since the time of Harvey. Modern criticism, however, has made it clear that neither treatise is a genuine work of Aristotle. It is especially plain that the treatise "On Spirits" is by another hand and of another school; among other reasons, because the author declares the skin to be supplied with blood by the veins, and with spirits by accompanying vessels which he calls "arteries." In this treatise the maintenance of the spirits by respiration is discussed, but left uncertain (483b, 15-19). It is but fair to the criticism of Harvey's time to note that, glaringly at variance as the undoubted works of Aristotle are with the treatise "On Spirits," the latter was pronounced genuine, in 1839, by so eminent a scholar as É. Littré, in his "Œuvres d'Hippocrate," etc., Vol. I, 203. Reasons why the treatises in question are not by Aristotle, are given at length in the essay in Latin by V. Rose, entitled "De Aristotelis Librorum Ordine et Auctoritate Commentatio," Berlin, 1854, 162-171, and at the end of 174.