Aristotle : On the parts of animals / translated, with introduction and notes by W. Ogle.
- Aristotle
- Date:
- 1882
Licence: Public Domain Mark
Credit: Aristotle : On the parts of animals / translated, with introduction and notes by W. Ogle. Source: Wellcome Collection.
255/316 page 207
![2. On- the question of the bilateral symmetry of the organs, and especially of the abdominal organs, where alone there is any difficulty, cf. Sylvestet, Disc, of Nature of Spleen, p. I2. 3. Cf. iii. 6, Note i. 4. By animals that necessarily have a spleen are meant, as will presently appear, the viviparous quadrupeds, or mammals; by those tha,t have it merely by way of token are meant the oviparous vertebrates, i.e. birds, reptiles, amphibia and fishes. The spleen is in fact notably largei; in the former than in the latter. There is some foundation for the statement that the size of the spleen and the distinct- ness with which the livef is divided into lobes are inversely related to each other. Thus it is in Mammalia that the spleen is largest in proportion to the body, and in them also that the liver is least distinctly lobulated. Among Mammalia it is the rodents that have the smallest spleen, and in these also it is that the liver reaches its maximum of sub- division. On the other hand, the spleen is large in ruminants and their liver at the same time presents scarcely any marks of lobulation. In- the Ovipara the spleen is much smaller than in Mammalia, and the li,ver, as a general though not universal rule, is much more decidedly cleft into distinct lobes. In all birds, in all batrachians, and in all reptiles, excepting Ophidia, the liver is distinctly divided into two lobes. In the remaining class, fishes, the spleen varies much in size ; sometimes is apparently altogether absent, some - times excessively small, sometimes almost as large in proportion to the body as that of a mammal, and the liver is sometimes multilobed, sometimes bilobed, sometimes unilobed. In this class, however, I cannot ascertain that there is any such relation as that rnentioned in the text between the two conditions. • 6. The exceptional ovipara are the Ophidia and many osseous fishes, where the liver is unilobed-. The exceptional vivipara are the rodents (see last Note), of which A. specially mentions the hare. “Near the lake Bolbe, and in bther parts, a species of hare is found, that might be taken to have two livers, because the ducts unite at a consider- able distance from the organ, just as is the case with [the bronchi from the two divisions of] the bird’s lung” {H. A. ii. ty, 4). ' 6. In cartilaginous fishes the liver consists of two distinct lobes, whereas in osseous fishes it is often unilobed. 7. Cf. iii. S, Note 4. - . 8. Assisting them in the mechanical way immediately mentioned, and also by providing an outlet for their surplus blood. Cf. iii. 13, Note l ; iii. 8, Note 2. 9. The mesentery is meant. 10. What 1 have translated “immoveably” is literally “like nails.” Thg introduption of nails into the metaphor is however so out of place, that I am strongly tempted to suggest that A. wrote euvcJi not ^\oi. Euvdi are the large round stones to which anchor- lines were fastened in old times. The metaphor would then run on all fours. The ship is the main bloocL-.vessel; the anchor-lines are the outstretching branches ; the round anchor-stones are the rounded liver, spleen, kidneys. 11. The hepatic and splenic arteries seem to have escaped A.'s notice ; probably because they are not given off directly from the aorta. 12. Plato described the spleen as made of bloodless substance. Cf. Jowett 's 7vans. ii. s66. 13. Cf. Note i8. • 14. The spleen is small in all birds, but whether specially so in these, or in the‘owl, which he adds elsewhere {H. A. ii. 15, 7) to the list, I cannot say. The stomach, argues 'A., is so hot in these birds as to be able to concoct food, without the aid of a spleen.](https://iiif.wellcomecollection.org/image/b24864249_0255.jp2/full/800%2C/0/default.jpg)
