ADDITIONS AND NOTES TO VOL. II. 



505 



varies from a yellow to a yellowish brown colour ; while in herbi- 

 vorous animals (rabbits, sheep, geese) it is green ; the colour of 

 the cystic bile in animals whose hepatic bile is yellow or brown, 

 has, however, always more or less of a tendency to green, and when 

 the animals have not fed for 20 hours or more is of a deep green ; 

 while, if examined 2 J or 3 hours after feeding, it is of as light a 

 yellow or yellowish brown colour as the hepatic bile. Since the 

 hepatic bile gradually becomes green on exposure to the air, and 

 the yellow tint may be again restored by deoxidising agents, there 

 can be no doubt that this change of colour depends on oxidation, 

 and that the bile retained in the gall-bladder is impregnated by 

 t^e c : rculating blood with so much oxygen as to induce this 

 altered colour. 



The prolonged retention of the bile in the gall-bladder induces, 

 however, not only a partial oxidation of this secretion, but also a 

 strong concentration, a fact which has been established by the 

 numerous observations of Bidder and Schmidt, and has been con- 

 firmed by Nasse. The former inquirers found that the fresh 

 hepatic secretion of cats, dogs, and sheep contained on an average 

 5 J of solid constituents, which in the case of cats and dogs rose 

 to 10 or even 20$- in the cystic bile, according to the duration of 

 its retention in the gall-bladder: in sheep, on the other hand, the 

 amount only rose to 8 ; in rabbits, whose fresh bile contains only 

 2-g- of solid constituents, the amount in the cystic bile may rise to 

 15-g-. The fresh bile of geese and crows contains about 7{r f solid 

 matters, which in the cystic bile of the former may rise to 20, 

 and in that of the latter even to 25 -. The bile, therefore, restores 

 to the blood and lymph a greater or smaller quantity of water, 

 according to the duration of its retention in the gall-bladder. 



(11) Addition to p. 78, line 18. [The experiments of Bidder 

 and Schmidt, which are here briefly referred to, are given in con- 

 siderable detail in the new edition. G. E. D.] 



Bidder and Schmidt have obtained the following results 

 regarding the absolute quantity of the bile secreted in 24 hours by 

 the animals on which they experimented. For one kilogramme's 

 weight of the animal there were secreted 



