1887] The Significance of Sex: 33 
ture of the gemmule, and not to the reticulum primarily as 
Nageli intended. But the discussion of this point belongs under 
the subject of heredity. 
It may be asked, what is gained by putting back the problems 
of life—of assimilation, of reproduction, and of heredity—one 
step; are they not as inscrutable as before? Undoubtedly they 
are, but we gain greatly by such a view as this. We can better 
understand the cell. Just as we simplified the problem of 4% as 
applied to the. higher animals, by the cell-doctrine, so we sim- 
plify by as great a step this protean problem by means of the 
gemmule hypothesis. We must accurately determine what are 
the real labors of the gemmule out of which, by organization, the 
more wonderful phenomena of cell-life grow, and then we shall 
see that we have spanned by a large fraction the chasm between 
non-living matter and living matter. The albumen molecule is 
a very minute thing when compared with the gemmule, and 
there is plenty of room for one or two stadia of organization 
between, that would, when known, simplify the problem com- 
pletely. On this hypothesis, also, cells must have a life-history 
in which they pass through stages of development and stop in 
various degrees of complexity as mature cells. The more highly 
organized cells must pass through the stages in which the less 
highly organized remain; and there is room here also for a phy- 
logeny and for cenogenetic modification. Finally, the simplest cells 
we know, must be to some extent modified from the condition 
in which the original cell was. This must be taken into account 
in trying to derive “living” protoplasm from “non-living” mat- - 
ter. The first gemmule could arise only by organization of a 
lower order of life, and the first cell must have been an aggre- 
gate of like gemmules produced by binary division of a mother 
gemmule. Reproduction in this hypothetical first cell we may 
reasonably suppose to have been effected in two ways,—either 
by a division of the gemmule colony into two smaller colonies, 
or by a dissolution of its members when each gemmule was set 
free to become the progenitor of its own cell-state. When dif- 
ferentiation came in, the primitive mode of reproduction became 
motie as ceg A few only of the gemmules were kept 
| tiated for purposes of reproduction. The others had 
to serve grat helping them to get better chance of food by 
carrying the colony about by amceboid or ciliary motion; others 
VOL. XXI.—NO. I, 3 : 
