Haacke 229 
of the germ cells with the other cells of the body. The 
body represents a system in equilibrium; if this changes 
the germ cells developing in it change also. But the 
equilibrium of the system constituted by the body becomes 
directly altered by the acquisition of new characters; con- 
sequently the changes which it undergoes must be trans- 
mitted also to the germ cells. But no matter whether the 
germ cells become changed as a result of the acquisition 
of new characters by the body which surrounds them, or 
whether they remain unchanged, they always inherit the 
same thing, namely, the capacity to form that body with 
which they were in equilibrium.” 174 
Like Spencer he supposes that this equilibrium is due 
to the tendency possessed by an infinite number of par- 
ticles, identical throughout the whole organism, to dis- 
pose themselves in this way only. His rhomboidal 
gemmes, grouped into composite units or gemmaria, are 
fundamentally nothing else than the physiological units 
of Spencer. The geometric form attributed to them, 
which emphasizes the static character of this explanation, 
does not make it in any way more acceptable. 
Nevertheless there are to be noted and carefully con- 
sidered, here perhaps, even more than in Spencer, the 
close interaction and the reciprocal equilibrating influence, 
which would always exist between the soma and the germ 
substance,—that is to say, between the organism and that 
small portion of its units contained in the reproductive 
cells,—not only throughout the whole development of the 
individual but also after the completion of development 
when the organism becomes subject to the modifications 
which external agents induce in it. 
1%4TTaacke: Kritische Beitrage zur Theorie der Vererbung und 
Formbildung. Biol. Centralbl., Bd. XV. 1895. P. 568. 
