A result, though perhaps an unconscious one, of the application and extension of these ideas, is, that within the last few years there has arisen a pathological theory of what are called ‘symmetrical diseases,’ the leading facts of which have been long known, but are now only beginning to be generalized. See Paget's Pathology, vol. i. pp. 18–22, vol. ii. pp. 244, 245; Simon's Pathology, pp. 210, 211; Carpenter's Human Physiol. pp. 607, 608.
[1114] Bichat sur la Vie, pp. 15–21.
[1115] Ibid. pp. 21–50.
[1116] On intermittence as a quality of animal life, see Holland's Medical Notes, pp. 313, 314, where Bichat is mentioned as its great expounder. As to the essential continuity of organic life, see Burdach's Physiologie, vol. vii. p. 420. M. Comte has made some interesting remarks on Bichat's law of intermittence. Philos. Positive, vol. iii. pp. 300, 395, 744, 745, 750, 751.
[1117] On the development arising from practice, see Bichat sur la Vie, pp. 207–225.
[1118] Ibid. pp. 189–203, 225–230. M. Broussais also (in his able work, Cours de Phrénologie, p. 487) says, that comparison only begins after birth; but surely this must be very doubtful. Few physiologists will deny that embryological phenomena, though neglected by metaphysicians, play a great part in shaping the future character; and I do not see how any system of psychology can be complete which ignores considerations, probable in themselves, and not refuted by special evidence. So carelessly, however, has this subject been investigated, that we have the most conflicting statements respecting even the vagitus uterinus, which, if it exists to the extent alleged by some physiologists, would be a decisive proof that animal life (in the sense of Bichat) does begin during the fœtal period. Compare Burdach, Physiol. vol. iv. pp. 113, 114, with Wagner's Physiol. p. 182.
[1119] ‘Les organes internes qui entrent alors en exercice, ou qui accroissent beaucoup leur action, n'ont besoin d'aucune éducation; ils atteignent tout à coup une perfection à laquelle ceux de la vie animale ne parviennent que par habitude d'agir souvent.’ Bichat sur la Vie, p. 231.
[1120] Dioscorides and Galen knew from 450 to 600 plants (Winckler, Geschichte der Botanik, 1854, pp. 34, 40); but, according to Cuvier (Eloges, vol. iii. p. 468), Linnæus, in 1778, ‘en indiquait environ huit mille espèces;’ and Meyen (Geog. of Plants, p. 4) says, at the time of Linnæus's death, ‘about 8,000 species were known.’ (Dr. Whewell, in his Bridgewater Treatise, p. 247, says, ‘about 10,000.’) Since then the progress has been uninterrupted; and in Henslow's Botany, 1837, p. 136, we are told that ‘the number of species already known and classified in works of botany amounts to about 60,000.’ Ten years later, Dr. Lindley (Vegetable Kingdom, 1847, p. 800) states them at 92,930; and two years afterwards, Mr. Balfour says ‘about 100,000.’ Balfour's Botany, 1849, p. 560. Such is the rate at which our knowledge of nature is advancing. To complete this historical note, I ought to have mentioned, that in 1812, Dr. Thomson says ‘nearly 30,000 species of plants have been examined and described.’ Thomson's Hist. of the Royal Society, p. 21.
[1121] It was published in 1790. Winckler, Gesch. der Botanik, p. 389. But the historians of botany have overlooked a short passage in Göthe's works, which proves that he had glimpses of the discovery in or before 1786. See Italiänische Reise, in Göthe's Werke, vol. ii. part ii. p. 286, Stuttgart, 1837, where he writes from Padua, in September 1786, ‘Hier in dieser neu mir entgegen tretenden Mannigfaltigkeit wird jener Gedanke immer lebendiger: dass man sich alle Pflanzengestalten vielleicht aus Einer entwickeln könne.’ There are some interesting remarks on this brilliant generalization in Owen's Parthenogenesis, 1849, pp. 53 seq.
[1122] That is, into the study of animal monstrosities, which, however capricious they may appear, are now understood to be the necessary result of preceding events. Within the last thirty years several of the laws of these unnatural births, as they used to be called, have been discovered; and it has been proved that, so far from being unnatural, they are strictly natural. A fresh science has thus been created, under the name of Teratology, which is destroying the old lusus naturæ in one of its last and favourite strongholds.