172 



FACULTIES OF BIRDS. 



Stomach of the Rotch, opened to show its internal structure. 



" makes the obstacles to the food in its passage to 

 the intestines unusually great, and enables the bird 

 to digest both fishes and sea-worms with crustaceous 



o 



shells. It appears to be given for the purpose of 

 economising the foo'd in two different ways; one, 

 retaining it longer in the cardiac cavity ; the other, 

 supplying that cavity with a greater quantity of 

 gastric liquor than in other birds. This opinion 

 is further confirmed by the habits of life of this par- 

 ticular species of bird, which spends a portion of the 

 year in the frozen regions of Nova Zembla, where 

 the supplies of nourishment must be both scanty and 



precarious * 



* Comp. Anat. i. 284. 



