32 The Significance of Sex. [Jan. 
ternate contraction with thickening, and stretching of the fibres of 
the reticulum. The nodes of the reticulum come closer together 
in some one direction, and get farther apart in the direction at right 
angles to this; at the same time the microsomata at the nodes ab- 
sorb the intervening microsomata. This looks as though the mat- 
ter of the microsomata was subject to mutual attractions and repul- 
sions, and then we could say that muscular movement is a special 
manifestation of those varied phenomena of division and fusion, 
attraction and separation of microsomata seen in karyokinesis.* 
However, this generalization cannot be made so long as we are 
uncertain whether the hyaloplasm or the microsomata are the 
primary thing, or whether they are independent but mutually 
reciprocal. If the microsomata (granules) are primary, then we 
must assume that the hyaloplasm is an aggregation of a special 
sort of these granules in a definite way to serve a definite func- 
tion. From the optical properties of the hyaloplasm this struc- 
ture must be regular and uniform. Others of these granules 
differentiate in various directions to serve various functions, and 
form, by various degrees of aggregation, the different sorts and 
sizes of microsomata. The primary granules from which all these 
other forms of protoplasm in the cell are derived must be en- 
dowed with the power of growth, of reproduction by simple di- 
vision, and of differentiation or variation. They would be affected 
by stimuli and vibrations travelling in the hyaloplasm in which 
they live. They should be designated gemmudes, because of all 
these properties. The cell, on this hypothesis, ts a gemmule state; 
it is a complex organism, with parts structured and differentiated 
for special ends for the good of the whole. The membranes for 
protection and osmosis, the reticulum for movement and trans- 
mission of sensations, the gemmule for assimilation and repro- 
duction. Degraded gemmules like differentiated and degraded 
cells form the various kinds of microsomata in the deutoplasm, and 
build up other parts of the cell. We shall see that the facts 
of cell-structure, of karyokinesis, and especially of fertilization, 
lend great weight in favor of this hypothesis. The gemmules are 
the idioplasm. They build up the cell in its peculiar characters 
and maintain it there. Under the above hypothesis the theory 
of Nageli as to the structure of idioplasm will apply to the struc- 
a See Figs. 12 and 93, d, and consult Van Beneden, Arch. Biol., iv. P- 343, and 
~ Melland, Quar. pe Mic. Sc., xxv., July, 1885. 
