FACTS 



235 



of this parasite (sexual maturation, for example) may show 

 itself in a very important transformation of its host if the 

 total transformation of the genital parasite has taken place 

 in the interval between two moults. This probably happens 

 to the species said to have complete metamorphosis, such as 

 butterflies and beetles. 



On the contrary, with other insects like grasshoppers, 

 the transformation of the genital parasite is effected in the 

 duration itself of several successive moults, at each of which 

 a relatively slight modification is produced in the host. 

 Thus the series of forms of the grasshopper, while it has the 

 character of an ascent of steps, has a more continuous aspect 

 than the corresponding series for the butterfly. It is as 

 if you substituted several steps for the sudden leap from 

 caterpillar to winged butterfly. We should not, however, 

 be right in saying that evolution is continuous in the grass- 

 hopper and discontinuous in the butterfly. It is discon- 

 tinuous in both cases, but in the first case a series of small 

 discontinuities takes the place of the enormous discon- 

 tinuity of the second. 



Yet another reason introduces between individual and 

 individual a stronger discontinuity than that which results 

 from the fabrication of a new skeleton subjected to the 

 rebound of variations acquired during the course of an 

 individual existence. It is amphimixis. 



Although we have no very certain knowledge of the 

 manner in which the hereditary patrimony of the egg is 

 constituted at the expense of the hereditary patrimonies of 

 the two parents, yet we can see with the utmost evidence 

 that in the phenomenon of fecundation there is a certain 

 discontinuity. The egg is something new. It has an here- 

 ditary patrimony which is neither that of the father nor 

 that of the mother, which constitutes itself in an instant 



