84 Hypothesis of Structure of Germ Substance 
ferentiated as it is through the division of labor, can 
receive to a certain extent the stamp of local character.” °4 
If we admit that each new specific current while 
passing through a nucleus deposits there the substance 
which was capable of producing it, and which would be 
capable on occasion of reproducing this same specific 
current,—a hypothesis of which we reserve a better 
exposition till later—we can conceive of nuclear soma- 
tization as a gradual and constant acquisition of new, 
specific, potential, somatic elements. 
The fact that each cell, as long as its differentiation 
has not progressed too far, can upon occasion, provided 
it be isolated from its neighbors, arise to the rank of a 
germinal cell, appears to indicate that these new somatic 
elements, thus gradually acquired, would from the start 
be simply added to the germinal elements already existing, 
without altering them at all, but merely relegating them 
to the potential state, from which, under normal 
conditions, they would not again emerge. 
In other terms we must suppose that all the germinal 
elements remain unaltered in the nuclei undergoing 
somatization as long as the number or the mass of 
acquired somatic elements does not progress beyond a 
given limit. 
But when this limit is once passed, then the require- 
ments of nutrition or of space would cause the different 
germinal elements to disappear gradually, and the nucleus 
concerned would thus lose all generative capacity. 
Further even those somatic elements, which each 
nucleus acquired one after another at each successive 
stage of development, will gradually disappear after 
“Oscar Hertwig: Zeit- und Streitfragen der Biologie. Praforma- 
tion oder Epigenese? Jena, Fischer, 1894. P. 142—143. 
