• Notes, iv. 2 — 5. .'219 



bladder are ' often found to be stained yellow from an exudation of bile. It is, I 

 imagine, to this overflow that reference is made, as being excessively sftiall in comparison 

 with the amount of bile which is apparent in the human body in cases of jaundice. 



•12. Residua include for A. not only excretions, but sundry useful secretions (cf. ii. 3, 

 Note 8). But some excretions are also utilised ; as in the case of the aurochs (iii. 2, • 

 Note 7), the cuttlefish (iv. 5, Note '21) ; and other animals (iii. 2, Note 8). 



13. Cf. Introd. p. iv. .* ' 



14. Cf. Note 6. . . • . 



15. Nutritious substances are always sweet, and never bitter (cf. iii. 5, Note 5). 



16. There are good reasons for believing that the bile does subserve an useful encf, by 

 facilitating the a,bsorption of fat. 



17. The camel is said by A. {H. A. viii. 9, 2) to live for 30 years, and exceptionally 

 for 100 years. Burckhart gives it a life of 40 years. As to the dolphin it is stated 

 {h. a. vi. 12, 6) that some had been marked by fishermen and let go ; and that by their 

 recapture it had been ascertained that they live at least 30 years. There are, I believe, 

 no modern observations on the matter. Horses are said {H. A. vi. 22, 8) to live, as 

 a rule from 18 to 20 years, and occasionally, if well tended, for 50 years ; mares being 

 somewhat longer-lixffed than stallions. Modern authorities give much the Same figures. 

 Stags are said by Flourons to live 30 — 40 years. It is strange that A. should here speak 

 of stags as long-lived ; for elsewhere (H. A. vi. 29, 4) he rejects the statements as to 

 their length of life as being mere fable, and says that the gestation and grovfth of a young 

 stag indicate the contrary. 



18. Cf. iii. 4, Note 37. 



19. Cf. iii. 7. ' 



(Ch. 3.) 1. His explanation is given in iii. 12. "Why some animals have a gall-bladder, 

 while others have none, is still unexplained in any satisfactory manner. It is rarely 

 wanting in Carnivora, very often wanting in Herbivora.. Still there are so many exceptions 

 to the general rule that it cannot be said that there is any direct relation -between the 

 presence or absence of this organ and the nature of the food. -Otherwise we might have 

 accepted the explanation {Buvernoy, Ann. des Sc. Nat. xxx, 127) that Carnivora have a 

 ^all-bladder because they eat at comparatively long intervals, and so require the bile to be 

 stored up for those occasions ; and that it is wanting in Herbivora, because they eat almost 

 continually, and so require a continuous flow of bile into the intestine. S. v. der Kolk 

 thinks that in animals without • a gall-bladder .the deficiency is compensated, as in the 

 elephant, by the greater width of the bile ducts (cf; Med. Chir. Revirw, 1862, p. 113). 



2. Cf. ii. 5, Note 6.- 



3. A similar statement is made elsewhere (iv. \,(>;,H. A. iii. 14). It is, however, 

 erroneous. Mammalia alone have an omentum. 



4. A. is apparently thinking of the formation of scum on the surface of boiled milk and 

 ■ the like. 



5. Cf. Introd. p. iv. . 



(Ch.. 4.) 1. That is of Hypothetical, not of Absolute, necessity: Cf. Introd. p. iii. 



2. Cf. ii. 3, Note 10 ; iii. ,5, Note 5. , 



3. Cf. ii. 3, Note 16. 



(Ch. 5.) 1.' Cf. iii. 4, Note I. ' 



2. Here, as often {e.g. iv. 9, 15 ; .iv. 10, 38), A. seems to speak of nature as being 

 in some way or other constrained to construct' her works in conformity with set types. 

 Cf. IntYod. p. X, and iii. 14, Note 4. • ' 



3, Urinary bladder and lung (iii. 8, i) were to A. signs of abundant blood ; and 



