1895.] Organic Variation. 897 
minute variations in the germ may yield marked variations 
in the adult. 
All this is offered as conjectural. If it be based on fact, 
some important conclusions follow. To atavism, partial or com- 
plete whether due to original germinal weakness or subsequent 
lack of nutrition, degeneration may be due. The imperfect or 
poorly developed offspring, if it should prove fitted to some 
other mode of life than that of its race, might survive and yield 
descendants like itself. Through such a process, long contin- 
ued, the extreme degeneration occasionally seen might appear. 
On the other hand, if the molecular groups can possess ex- 
cess of energy or superfluous material, the result may be seen 
in some unusually large organ or greatly developed tissue, or 
a general superiority of the whole body; or, again, in the ap- 
pearance of some duplicate part or excrescence. Such an 
excess, if advantageous, might, as in the opposite case of de- 
generation, induce new habits in the animal, and, in time, 
lead to marked differences in species. If the excess appeared 
in the nervous system generally, or the brain particularly, an 
important psychical advance might result. It is certainly not 
impossible that the extraordinary intellectual powers which 
occasionally appear in the offspring of parents of ordinary 
mental development may be due to this cause, and that the 
gradual advance in mental ability in the animal kingdom, 
with the superior powers of attack and defence thence arising, 
have a similar origin. 
The problems here dealt with are very obscure ones. In 
considering them we are, perforce, confined to hypothesis, 
since facts are beyond our reach, other than such phenomena ~ 
of organic nature as have been adduced. Certainly the causes 
of individual variation lie low down in the process of develop- 
ment, and while, perhaps, due in a measure to environmental 
‘forces at work on the embryo or larva, are probably due in a 
much larger measure to conditions connected with the organi- 
zation and early development of the germinal cell. 
