TASTE OF PISCIVOROUS BIRDS. 



171 



bird swallow a fish, go to its nest, and regurgitate it 

 into the mouth of its young, and in that short time 

 the skin of the fish had quite disappeared. In the 

 second case, as in the sea-mew (Lams canus), and 

 the flamingo, the gizzard has not only a thick lining, 

 but there is a strong digastric muscle, evidently for the 

 purpose of enabling the birds to feed on shell-fish. 



The gizzard and cardiac cavity of the Pea-mew, opened to show its internal 

 structure. 



A still more striking construction of the digestive 

 organs is found in the rotch (Mergulus melanoleucus, 

 RAY). The gullet may be said to form almost a 

 continuous tube descending below the portion where 

 the solvent glands are situated, and then rebending 

 upwards again towards the right, and entering a 

 small gizzard furnished with a strong digastric 

 muscle. The extent of the cavity containing the 

 solvent glands, and turn which it takes almost di- 

 rectly upwards, the gizzard being at the highest in- 

 stead of the lowest part, appear to be peculiar to this 

 species. " This mechanism," says Sir Everard Home, 



