GENERATION OF ANIMALS, III. ii. 



the situation where they happen to be is sunny, the 

 eggs of birds " as well as of oviparous quadrupeds get 

 fully concocted without incubation (for all these 

 quadrupeds lay their eggs on the ground, and they 

 get concocted by the heat in the earth ; any o\i- 

 parous quadrupeds which visit their eggs and sit on 

 them do so rather for the sake of protecting them 

 than for any other reason). 



The eggs of quadrupeds are formed in the same 

 way as birds' eggs. They are hard-shelled, and 

 double-coloured, take shape up towards the dia- 

 phragm (as birds' eggs do), and present the same 

 features in every other respect both externally and 

 internally ; so that studying the cause of any of them 

 is the same as studying the cause of them all. Only, 

 whereas the eggs of quadrupeds, being so strong, get 

 fully concocted by the agency of the climate, birds' 

 eggs, being more fragile, need the mother-bird. It 

 looks as though Nature herself desires to provide 

 that there shall be a feeling of attention and care for 

 the young offspring. In the inferior animals this feel- 

 ing which she implants lasts only until the moment 

 of birth ; in others, until the offspring reaches its 

 perfect development ; and in those that have 

 more intelUgence, until its upbringing is completed. 

 Those which are endowed ^vith most intelligence show 

 intimacy and attachment towards their offspring even 

 after they have reached their perfect development 

 (human beings and some of the quadrupeds are 

 examples of this) ; birds show it until they have 

 produced their chicks and brought them up ; and on 

 this account hen birds which have laid eggs but omit 



similar way : " she leaveth her eggs on the earth, and 

 warmeth them in the dust " (R.^'.), 



L 289 



