326 OWEN'S POSITION IN 



into contact with A, but fuses with it ; so that the 

 substance of the progeny is A + B, and not merely 

 A ? What we want to explain is, not only why 

 sexless proliferation takes place in the animals or 

 plants in which it occurs, but why it does not take 

 place in other closely allied forms. It is not 

 legitimate to assume that sexless proliferation is 

 secondary and exceptional, and sexual proliferation 

 primary and normal. On the face of the matter, 

 it is just as likely to be the other way. 



In the essay under consideration, however, 

 Owen starts with this assumption. He conceives 

 that B is the agent by which a certain \ spermatic 

 force ' is transmitted to A ; and that, when appa- 

 rently sexless proliferation takes place, the evolu- 

 tion of the germs is really due to the presence in 

 them of this hypothetical ' spermatic force,' trans- 

 mitted from the first sexual proliferation. Starting 

 from the established truth that, where sex is con- 

 cerned, the essential step of the production of 

 progeny is the coalescence of substances contained 

 in two cells, one derived from the one parent, and 

 one from the other, and the subsequent division 

 and subdivision (with concomitant growth) of the 

 combined mass into the primary cells of which 

 the embryo is constructed, Owen goes on to say 



(P- 5) :- 



' Not all the progeny of the primary impreg- 

 nated germ-cell are required for the formation of 

 the body in all animals ; certain of the derivative 



