1887] The Significance of Sex. 39 
plasm, thin at first, grows out as an envelope about them, much 
as in Dallinger’s monad. (See F. R. M. S., July, 1886, and Fig. 
98.) When the cells are completed, they multiply by indirect” 
division (karyokinesis), but not to a very great extent, if destined 
to become ova. In this case a period of growth, of storage of 
nutriment for the future embryo, ensues, and when this work 
is completed, the ovum shows its homodynamous nature with 
the spermatozoon by completing its delayed divisions by the 
formation of the polar globules. Why these divisions are thus 
delayed will be discussed in its proper place. 
If the ovum has its special work to do, division of labor has 
also given the spermatozoon its special work. For the large and 
stationary ovum must be sought out and penetrated, and so the 
enveloping cytoplasm is built up into the proper locomotor or- 
gans, which gives the male cell its characteristic and varied 
forms. We see that the characters which distinguish the male 
from the female gamete, or vice versa, are purely secondary and 
acquired characters, and, in the absence of these, we would be 
unable to distinguish sex. We shall endeavor to show that she 
chromatin is not sexed, but probably differs in the two cells by an 
infinitesimal variation. So far as our idea of sex implies the 
differentiation of MALE from FEMALE, the chromatin ts not sexed, 
but so far as it implies DESIRE FOR CONJUGATION with other chro- 
matin differing from it by a slight variation, and likewise filled with 
‘a longing for conjugation, it (the chromatin) is sexed, but to this 
idea of sex the thought of male and female is foreign. Male and 
female are ideas that have arisen in contemplating the different 
secondary mechanisms that have been evolved for the purpose 
of effecting conjugation; and these characters are the result of 
the operation of the same principles that have differentiated a 
gland-cell from an epithelium-cell. 
But, let us see how these secondary or sexual mechanisms 
differ, and how the nucleus is related to them. We first consider 
the changes that are suffered by the nucleus of 
: THE OVUM. 
Most of the observations on the germinal vesicle (nucleus of 
the ovum) relate to its behavior in relation to the polar globules, 
which does not now concern us; for we now know that this is 
simply the nucleus dividing by karyokinesis so as to become 
