24 INTRODUCTION. 



fashion, and as the result of a series of unconscious, or 

 so-called reflex movements, which are caused by the fact 

 that from twenty-four to thirty-six hours before hatching 

 the chicken begins to breathe, and at last requires more air 

 than can pass through the shell. Hence arises a great 

 danger of suffocation, and in conseqirence of this strong 

 reflex action takes place, by means of which the chick is 

 caused to strike, pr push violently against the inner wall of 

 the shell with a sharp bony point formed on the beak, and 

 the whole body is stretched and extended. Pressure is 

 caused by the natural growth of the body within, and the 

 breaking of the shell cannot long be delayed. 



But when the chicken is out of its shell it is far from 

 running about and picking Tip corn. It generally lies for 

 about two hours helpless on its stomach, and neither eats 

 nor pecks, even though a grain of corn be placed in its beak. 

 It then begins to make feeble attempts to move, in which it 

 at first uses its wings just as though they were crutches. It 

 gets up,- falls down again, falls down and gets up, so that its 

 motion looks more like slipping than running. If a noise 

 is made near it, for instance if anyone knocks a table with 

 the finger, it turns to the side of the noise, and this is not 

 surprising, as its ear has already to a small extent been used 

 within the shell. During the next six hours, the chick 

 gradually gains strength and practice enough to run, and it 

 also begins to peck at the ground, but blindly and sense- 

 lessly; for it pecks at everything which reaches its eye, such 

 as little lumps of earth, heads of nails knocked into the 

 boards, grains of sand, and glass-beads, and even at mere 

 bright specks which may have been brought on to the table 

 or slate shelf among the chalk. This is done also by grown 

 poultry, which are frequently seen to peck at the ground 

 although there is nothing there to pick up. They also, like 

 the chickens, peck at pieces of chalk, until experience has 

 taught them that it is useless. Even poultry from which 

 the cerebrum has been removed, and which are therefore 

 without consciousness and without feeling, strike mechani- 

 cally with their beaks on the ground without picking up 

 corn. ju.t in the same way as human babies try to put into 

 their mouths whatever is given them. It ought not, there- 

 fore, to be surprising that chickens should do the same, 

 especially when imitation of the pecking mother comes into 



