368 HISTORY OF 



The next generation is of those animals that we 

 see produced from the egg. In this manner all 

 birds, most fishes, and many of the insect tribes, 

 are brought forth. An egg may be considered 

 as a womb, detached from the body of the parent 

 animal, in which the embryo is but just beginning 

 to be formed. It may be regarded as a kind of 

 incomplete delivery, in which the animal is dis- 

 burdened of its young, before its perfect forma- 

 tion. Fishes and insects, indeed, most usually 

 commit the care of their eggs to hazard ; but 

 birds, which are more perfectly formed, are 

 found to hatch them into maturity by the warmth 

 of their bodies. However, any other heat of the 

 same temperature would answer the end as well j 

 for either the warmth of the sun, or of a stove, is 

 equally efficacious in bringing the animal in the 

 egg to perfection. In this respect, therefore, we 

 may consider generation from the egg as inferior 

 to that in w r hich the animal is brought forth alive. 

 Nature has taken care of the viviparous animal 

 in every stage of its existence. That force which 

 separates it from the parent, separates it from 

 life ; and the embryo is shielded with unceasing 

 protection till it arrives at exclusion. But it is 

 different with the little animal in the egg ; often 

 totally neglected by the parent, and always sepa- 

 rable from it, every accident may retard its 

 growth, or even destroy its existence. Besides, 

 art or accident also may bring this animal to a 

 state of perfection ; so that it can never be con- 

 sidered as a complete work of nature, in which 

 so much is left for accident to finish or destroy. 



