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asserts that when the germinal matter (of the residuum 
of the stirp) is everywhere affected by the same conditions, 
it would be everywhere affected in the same way ; that, 
where the sexual elements are thus modified, they pro 
duce corresponding modifications in the offspring ; and 
last, but not least in importance, that the modification 
in the parents’ organisms and sexual elements takes place 
at the same time ; and sometimes the sexual elements 
are modified when the body is not. Here, then, we have 
a modification taking place before birth in all the indi 
viduals subjected to a given influence—and a modification 
which can be inherited by offspring. Whether the modi 
fications of the body can be inherited or not, is a small 
matter, if the sexual elements are similarly modified and 
reproduce these modifications in offspring. These similar 
variations will be reproduced and fixed in the race without 
the intervention of the principle of selection. 
Very similar to the theory of Mr. Galton is Dr. Weis- 
mann's doctrine of the “ Continuity of the Germ Plasm,” 
at which the author has laboured now for many years, 
during which the theory has undergone considerable 
modification. The germ plasm is the name given to the 
contents of the germ cells, in sexual reproduction, the 
germ cells are supposed to produce the cells which go 
to build up the body of the offspring, and therefore called 
somatic (body) cells. In doing this, it is possible that 
all the contents of the germ cells should be used up in 
producing the body cells, and that then the body cells 
should produce the germ cells de novo. Or it is possible 
that only a portion of the contents of the germ cells 
should be used up, and that what remains should form 
the germ cells of future generations. The first of these 
conceivable methods Dr. Weismann designates as the 
cyclical development of the germ plasm ; the latter he