vI FORM AND FUNCTION 63 
keel developed only on the hinder part of its breast- 
bone, is remarkable also for its highly muscular crop 
with furrows and ridges, by means of which it squeezes 
out the juices of leaves. In some birds the crop is 
altogether wanting.. In Cormorants, Flamingoes, and 
Pelicans only a very small expansion, that might 
easily escape notice, has been found. In all fish- 
eaters it is either, as in those just mentioned, very 
slightly developed or non-existent. The two most 
striking points about a Cormorant’s gullet are its 
great size and its elasticity. Just below the mouth it 
opens out to form a spacious pouch with very thin 
walls. Below that it narrows but very slightly before 
there comes the very small expansion representing the 
crop, and its -walls are there just a trifle thicker. 
When the bird is lucky enough to secure a long and 
thick fish this great tube of nearly uniform size is 
ready to receive it. There is no contraction at any 
point sufficient to hinder its downward progress. A 
crop narrowing down at its lower end to a small tube 
formed of strong walls would be out of the question in 
a fish-eater. In diving-birds, fish have been found 
with their heads partly digested, while upon their 
bodies, which had not yet reached the stomach, the 
process had not yet begun. This must inevitably. be 
so, since nothing is more remarkable than the narrow- 
ness of the band within the area of which lie the 
digestive glands: a fish of any length cannot possibly 
come under the influence of the juices all at once. 
Nearly all the stowage room for the cormorant’s 
large meals is in the ample gullet, and great demands 
are made upon it. One of these huge feeders was 
