398 LEAVES FEOM THE 



tinct conditions and situations. The food fitted for one 

 stage of life is rejected at another. 



Animal life (as Hunter observes) may be divided into 

 three states, or stages: the first comprehending the pro- 

 duction of the animal, and its growth in the foetal state ; 

 the second commencing when it emerges from that state 

 by what is called the birth, but leaving it for a time, 

 either mediately or immediately dependent on the 

 parent for support ; the third, when the animal is able to 

 act for itself As a general proposition, it may be laid 

 down that the first and third stages are common to all 

 animals; but some classes — fishes and spiders, for in- 

 stance—pass directly from the first to the third, having 

 no intermediate stage. 



The great physiologist then notices the infinite variety 

 in which Nature provides for the support of the young 

 in the second stage of animal life, and that brings him to 

 the statement of his discovery. He tells us, and tells us 

 truly, that the young pigeon, like the young quadruped, 

 till it is capable of digesting the common food of its kind, 

 is fed with a substance secreted for that purpose by the 

 parent ; not, as in the mammalia, by the female alone, 

 but by the male also, and perhaps more abundantly than 

 by the female. 



Every person who has kept parrots, maccaws, and birds 

 generally of that family, must have noticed the power 

 possessed by them of throwing up the contents of the 

 crop, and feeding each other. Hunter, in common with 

 others, saw a cock paroquet regularly feed his hen, by 

 first filling his own crop, and supplying her thence from 

 his beak ; and he notices, what every observer who has 

 kept such birds must have remarked — namely, that when 

 they are very fond of the person who feeds and attends 

 upon them, they perform the action of throwing up food, 

 and often do it. The cock pigeon, when he caresses the 

 hen, goes through the same forms of action as when he 



