CHAPTER XXII. 
HOW SOME GROWN-UP BIRDS GET A LIVING. 
Wuitr, as noted, some birds give their young 
food differing from that which they eat when grown, 
yet the rule is that parent and children fare alike. 
This is peculiarly the case with fish eaters and neces- 
sarily so with the regurgitators. 
Our last topic, therefore, leads us into this. 
At the time when the ancestors of many of our 
modern birds all had teéth the diet was evidently 
not vegetable, but was more likely of fish and other 
aquatic life. It is probable that either the bird ceased 
to fare upon flesh or else took to gulping its food 
whole without chewing. The lowest of birds now— 
the ostrich forms—are noted for their ‘“ most uncom- 
mon bolts”; but their wholesale swallowing of hard 
substances is a necessary consequence of the loss of 
teeth and not the cause of it. The birds are the first 
users of artificial teeth, but they shifted them from 
the mouth to the stomach, and the dawn of the gizzard 
doubtless came in with the loss of the fang in the jaw. 
Flesh eaters, it is well known, have small use for 
the tough, muscular, grinding pouch, with its pebbles 
and other triturating things; and in them it is often 
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