70 COLUMBjE. 



bird has ceased to take in a supply by the bill. That 

 dilatable portion is called the craw or " crop," and bears some 

 resemblance to the paunch or first stomach in ruminating 

 quadrupeds. It is probable that the food of all birds, when 

 requiring such a preparation, is moistened and macerated 

 there before it passes into the stomach. But in the columbse, 

 there is a peculiar change in the organ for the feeding of the 

 young, a change which has some resemblance to the produc- 

 tion of milk in the mammalia, only it takes place in both the 

 parent birds. At that time the inner coat becomes covered 

 with small glands, which secrete a peculiar fluid which 

 acquires a consistency resembling that of soft curd. When 

 the young first break the shell, they are fed upon that sub- 

 stance, wholly or nearly in a pure state ; but as they grow, it 

 gradually mingles with more and more of the food of the 

 parent bird, which it reduces to a sort of pulp ; and when 

 the young are able to feed themselves, the secretion disap- 

 pears, and the glands that produced it are inactive until they 

 again are required for the feeding of another progeny. 



The food which the pigeons thus prepare for their young, 

 whether it be the curdy secretion of their own bodies, or food 

 which they have picked up and prepared, is not given to the 

 young by the bill, in the way in which the majority of birds 

 feed their young. The old one puts its bill half-opened, 

 fairly into that of the young one, and the food is brought up 

 and delivered to it by a peculiar action of the gullet. 



That habit, approaching more nearly to maternal tenderness 

 than perhaps any other in birds, the fact that they are only 

 two young in a brood, and that these are generally a male and 

 female ; the attachment of the pair which, notwithstanding 

 the disposition which pigeons have to flock (and in some 

 countries they flock in countless millions), we have reason to 

 believe they preserve through life : and their apparent fondness 

 for each other, to which there is no parallel instance in the whole 



