STOMACHS IN BIRDS. 185 



often in irregular rows. In pigeons, which feed the young 

 from the crop, these glands swell remarkably during the time 

 that this mode of feeding continues. What is singular is, that 

 corresponding changes take place in the crop of the male 

 pigeon during the period of incubation. For the first three 

 days after exclusion from the egg, the young pigeon receives 

 no nourishment but what is derived from the crop. 



Stomach. The second stomach is funnel-shaped, hence called 

 infundibulum. It is also named ventriculus succenturiatus, 

 and the glandular stomach ; it is situated in the abdomen, and 

 is commonly smaller than the crop : it is more general in the 

 order of birds than the crop, while in the different species it 

 varies much. It obtains a covering from the peritoneum : it is 

 thicker even than the gullet, but this thickness is due rather 

 to the numerous glands which secrete its peculiar fluid than 

 to greater muscularity. These follicles are placed vertically, 

 forming rows very close to each other, and superimposed one 

 on another with orifices directed downwards : these follicles 

 reach their maximum development in granivorous birds. In 

 these they are besides divided into a great number of denticu- 

 lated appendages. Their form is without exception that of 

 elongated tubes closed at the inner extremity. 



Gizzard. The infundibulum, or second stomach, ends in the 

 gizzard, or third stomach. So close are these two stomachs that 

 many authors describe them together as the one stomach of birds, 

 divided into two cavities. It is more convenient, however, to 

 speak of them as the second and third stomachs. This third 

 stomach, or gizzard, is often, in works of anatomy, termed the 

 ventriculus callosus. In gallinaceous birds it is much larger 

 than the second stomach ; in other birds, for the most part, it 

 is the reverse. It is generally situated in the upper part of 

 the abdomen, close to the spine, and resting on the intestines. 

 In a few birds it is covered by the intestines. 



