208 ELEMENTS OF ORNITHOLOGY. 
may be feathery, as in the Toucans and Honey-eaters ; or it 
may be a mere rudiment at the bottom of the mouth, as in the 
Kinetisher and Pelican. Very rarely, as in the Bustard, a large 
pouch may open beneath the front of the tongue and be capable 
of much distension with air. 
ulne gullet, or esophagus, is sometimes very capacious. It 
may also have a special dilatation in front, called a crop or in- 
AUREL wherein food can be temporarily retained, and sometimes 
macerated, before reaching the stomach. Sometimes, as in the 
Pigeon, there may be a double crop, and it may furnish a milky 
secretion at the breeding-season. Birds of prey throw up the 
indigestible parts of their food as « castings.” Other birds throw 
up part of their food to feed their young. The Hornbill will 
throw up the lining of its stomach. 
At the lower end of the eullet is the digestive stomach or 
proventriculus, which answers to that part of our own stomach 
which is called the “cardia.” It is richly supped with 
glands. 
The next segment of the alimentary canal is the gizzard, 
priich answers to that part of our stomach which is called the 
“ nylorus.” It generally has very thick fleshy walls, with only 
a small internal cavity provided with a horny lining. It is 
into this cavity that birds swallow down stones, w hich when 
brought to bear on food by contractions of the ‘eizzard’s very 
muscular walls, act as teeth and grind the grains or other 
hard substances fed upon. In birds that feed on food which 
needs no grinding, the gizzard’s walls are much thinner. 
The intestine is much shorter relatively than in us. In the 
Toucan it is hardly twice as long as the bird’s body and bill. 
It generally consists, as in ourselves, of two parts: an anterior 
small intestine, which is continued into a shorter part called the 
large intestine. The foldings of the intestine vary in arrange- 
ment, especially those of the small intestine, and these arrange- 
ments distinguish certain groups of birds. There is but little 
difference of capacity between the so-called “small” and 
“large” intestine. The anterior part of the small intestine is 
called the duodenum, and this part is disposed in a pretty con- 
stant fold called the “duodenal fold.” he hinder part of the 
large intestine is called the rectum. The transition between 
the small and the large intestine is usually marked by a pair of 
hollow offshoots or diverticula, called the ewea. These may 
be very small or very large or of moderate size. Instead of a 
