THE LIVER, ABSORBENTS; HABITS. 55 



culiar in another respect. See the account of the Demoiselle 

 Heron, note 23, Part I. 



The liver is largest in those birds whose respiratory organs 

 are the least; hence Mr. Green, in his Lectures at the 

 College of Surgeons before alluded to, conjectures that the 

 office of that viscus, (not only in birds, but also in the mam- 

 malia,) besides its known one of secreting the bile, is to 

 effect some material change in the blood, and, thence, he 

 considers it as a subsidiary or ventral lung. 



The absorbent vessels in birds arise from the villous coat 

 of the intestines in a similar way to those in the mammalia. 

 Here again, Mr. Green thinks, that they give out their 

 contents to the blood not only by means of the thoracic duct, 

 but also by many other communications which they have in 

 different parts of the body with the veins.* 



There is no doubt, however, that the food as well as the 

 natural habits of birds may be greatly altered by domestica- 

 tion, as well as other causes ; when a corresponding change 

 in the structure of the stomach may be presumed, and has been 

 occasionally observed. Eagles have been supported wholly 

 on bread. Mr. Southey informs me, that some lads having 

 taken a young Owl in the neighbourhood of Keswick Lake, 

 they fed him with fish, which he liked well and throve 

 upon. Mr. Southey thinks this fact indicative of the same 

 sympathy or kindred likings as those of the cat ; — both it is 

 well known feed upon mice. The youths living beside the 

 lake, and being fond of fishing, they could take small perch 



* This was mentioned by Mr. Green in his Lectures, 

 chiefly for the purpose of exciting attention to the conjecture ; 

 namely, that not only in birds, but also in man, the absorbents 

 poor their contents into the blood by many other communications 

 with it, besides that directly of the thoracic duct. 



