Darwin. 281 
Of Darwin’s pangenesis it is necessary here to men- 
tion only the conception that the sexual or reproductive 
organs in general were not so much the place of refuge to 
which the germ plasm withdrew immediately after its 
separation from the soma at the very commencement of 
development, as rather the containers of the germinal 
substance continually produced and secreted by other 
parts of the organism lying without these organs, so that 
they build up as it were the sexual or reproductive 
cells out of this valuable material thus received and 
accumulated.?12 
In Darwin’s hypothesis this conception of the repro- 
ductive organs as mere glands for the reception and 
giving up again of the germinal substance was intimately 
associated, although in its essence quite separate and 
independent, with his further conception of the free 
circulation of the gemmules throughout the organism; 
and he supposes, as is known, that these gemmules were 
produced and secreted continuously during the adult state 
by all somatic cells indiscriminately—by those already 
present as well as by those just appearing in consequence 
of a new functional adaptation. Now if Galton by his 
experiments on the transfusion of blood from a rabbit of 
one species to the blood vessels of another belonging to a 
related species, has provoked a thoroughly justifiable 
doubt of this supposed circulation of gemmules, especially 
in so far as it was carried on in the blood vessels, the 
original idea remained nevertheless unshaken, that is that 
the germinal substance is assembled in the sexual glands 
after it has been formed in some real place of origin 
external to them. 
212Darwin: The Variation of Animals and Plants under Domesti-+ 
cation. II. P. 370, 379. 
