THE SPERMATOPHORE IN ARENICOLA 1038 
SEXUALITY AND REDUCTION 
Many biologists are inclined to regard sexuality and reduction 
as causally related. Thus Davis says ‘‘Chromosome reduction 
as a physiological process seems to be a corollary of sexual nuclear 
functions.” (Bot. Gaz., vol. 43: p. 109.) If either were the 
effect of the other, we should expect reduction to bear a fixed 
relation to the sexual act. As itis we have seen that it may occur 
before, during or after such act. It would be better to say, then, 
that reduction is an adjunct of sexuality and both are probably 
corollaries of some fundamental cause yet to be determined. 
It has been suggested by Biitschli and later writers that the 
union of the gametes is a process of rejuvenescence. In other 
words, the sexual act is induced by exhaustion of the organism. 
We know that chromidia are due to degeneration produced by 
exhaustion and otherwise (Dobell, ’07). Further, a very simple 
type of reduction has been found in some protozoa (Monas, 
Adelea, etc.) to consist of the extrusion of chromidia. The very 
incomplete state of our knowledge regarding reduction, chromidia 
and sex, particularly among the lower plants and animals, makes 
the proposal of even a working hypothesis premature. I call 
attention to the exhaustion of the organism through repeated 
asexual divisions as a possible cause of both sexual union and 
reduction, merely to illustrate the possibility that both are corol- 
laries of some underlying single cause. 
About the only justifiable conclusion regarding the phylogenetic 
relation between the sexual act and reduction is that they arose as 
adjacent phenomena. This seems probable, since in primitive 
forms, both plants and animals, they occur close together in point 
of time. It would seem, on a priori grounds, too, that if a sexual 
union occurred in forms that had been producing asexually, a 
reduction in the amount of chromatin would promptly occur if 
it had not occurred previous to the act, so as to restore customary 
conditions as speedily as possible. 
