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 
