166 HABITS OF BIRDS. 



remarked, that the head, compared with the bulk of 

 the body, is very heavy ; and it makes, together with 

 the neck, a load which the chick, even for several 

 days after its exclusion, can with difficulty support. 

 But in the egg-, let the position be what it may, the 

 head is supported either by the body or by the wing, 

 or by both together ; and the greater the size of the 

 head, the more efficient of course are the blows of the 

 bill. The length of the neck causes it to be bent 

 at this time, though after the first fourteen days it 

 becomes nearly straight ; but what seems to be done 

 out of necessity to procure room, is here, as in many 

 other operations of nature, the best thing that possibly 

 could have been done out of choice. 



By watching at the proper time, Reaumur fre- 

 quently heard chicks hammering upon the shell with 

 their beaks ; and in the more advanced stages of the 

 operation he could actually see them at work, through 

 the translucent membrane. The result of the first 

 strokes is a small crack, commonly situated nearer 

 the larger than the smaller end of the egg. When 

 this crack is perceptible, the egg is said to be chipped, 

 The membrane is seldom ruptured in the first in- 

 stance, even when the hard part of the shell over it is 

 detached ; but in one instance, while Reaumur was 

 observing the operations of a chick by candle-light, 

 it was hard at work pecking at the membrane divested 

 of its shell. It did not strike, however, but seemed 

 as if endeavouring to wear it out, and make it thin- 

 ner by continued friction. 



The continued blows extend the first cracks, and 

 new pieces of shell are driven off almost all in the 

 same circle, the blows running round nearly the 

 whole circumference of a circle which never cuts the 

 egg obliquely, but always directly across ; yet the 

 bill all the while remains under the wing, and always 

 in the same position. In order to accomplish this, 



