GENERATION OF ANIMALS, II. i. 



a soft one : the earthy substance does not come to 

 the surface in the egg any more than it does in the 

 creature wliich lays it. And that is why they lay 

 their eggs internally : if the eggs emerged they 

 would be destroyed through lack of protection. 



Animals that tend to be cold and solid lay eggs, 

 it is true, but their egg is imperfect, and it has a 

 hard covering (a) because the animals themselves are 

 earthy and (6) because it is in an imperfect state 

 when laid, and the shelly exterior serves as a pro- 

 tection to keep it safe. Thus fishes, being scaly, and 

 Crustacea, being earthy, produce eggs with a hard 

 covering ; while the Cephalopods, which also lay 

 imperfect eggs, keep them safe by a method in ac- 

 cordance with the sticky nature of their own bodies ; 

 they exude a large amount of sticky substance over 

 the fetation. Insects all produce larvae. Now all 

 Insects are bloodless, and that actually is why they 

 are externally larva-producing. But it is not true 

 that all bloodless animals are larva-producing without 

 qualification, because there is overlapping as between 

 the larva-producing animals and those that produce 

 imperfect eggs (e.g., the scaly fishes, the Crustacea 

 and the Cephalopods), since the eggs of the latter 

 are larva-like, in that they grow bigger after they 

 have been laid externally, while the larvae of the 

 former, as they develop, become egg-like : we shall 

 explain later how this happens." 



We should notice how well Nature brings genera- 

 tion about in its several forms : they are arranged in 

 a regular series, thus : (1) The more perfect and 

 hotter of the animals produce their young in a perfect 

 state so far as their quality is concerned (no animal 

 brings forth young that are perfect in size, because 



141 



