562 THE BEGINNINGS OF LIFE. 



and become metamorphosed into a Rotifer, this in 

 turn, when it multiplies, whether agamically or by 

 true eggs_, produces other Rotifers. Again, it has been 

 ascertained that both Rotifers and Nematoids are 

 capable of arising directly from transforming vegetal 

 vesicles if they are of sufficient size, and provided they 

 undergo some unknown though probably distinct pro- 

 cesses of total molecular change. And the forms which 

 have been thus produced also multiply their own kind, 

 without exhibiting the least tendency to reproduce a 

 vegetal organism similar to that from which the trans- 

 forming vesicles had been derived. 



As soon as new forms arise which habitually pro- 

 duce internal buds or eggs, such organisms may be sepa- 

 rated in an important manner from those ephemero- 

 morphs from which they have been produced. Amongst 

 animals and plants in which such processes occur, we 

 begin to find those definitely recurring forms constituting 

 ^ species,' to which we have above alluded, because 

 homogenesis has now become the rule, and the sexual 

 method of reproduction has more or less definitely 

 commenced. This sexual differentiation, as we have 

 seen, has been rapidly attained by some of the highest 

 representatives of heterogenetic transformations, and 

 some of these forms, such as Nematoids, afterwards 

 continue to multiply themselves through successive 

 generations by a sexual and homogenetic method. . 



Seeing that the product of transformation in each of the 

 above-mentioned cases subsequently multiplies (as long 



