168 HABITS OF BIRDS. 



fracture towards the right, so that the bill might have 

 nothing to strike against. 



" Accordingly, I protracted considerably the small 

 fracture made in two different eggs, taking off pieces 

 both of the shell and the membrane as far as I went, 

 purposely to see what would happen to the chicks. 

 Unfortunately for the theory, the consequence was, 

 that each chick was sooner released from confine- 

 ment than if it had had to effect its own exit. I had 

 saved it part of the work, and it very well knew how 

 to change its place, so as to be able to break the 

 remaining part of the shell *." 



The fracture may be observed to be broader in some 

 eggs and narrower in others, and even of different 

 breadths in the same egg; while only a few pieces 

 are broken off in some and a great number in others, 

 the latter case exhibiting all the irregularities of a 

 glass bottle broken by the repeated gentle blows of 

 a hammer. The effect required to be produced is, 

 the entire separation of the two portions, first of the 

 hard shell, and then of the membrane, which is torn 

 by repeatedly pecking it with the bill. All chicks 

 do not succeed in producing this result in the same 

 period of time, some being able to perform the task 

 within an hour, others taking two or three hours, 

 while half a day is most usually employed, and 

 some require twenty-four hours. " I have seen 

 chicks," says Reaumur, " continue at work for two 

 days together. Some again work incessantly; others 

 take rest at intervals according to their physical 

 strength. I have observed some, in consequence of 

 their impatience to see the light, begin to break the 

 shell a great deal too soon ; ibr they ought, before 

 they make their exit, to have within them provision 

 enough to serve for twenty-four hours without taking 

 * Oiseaux Domestiques, Mem. torn. vi. 



