526 CHARLES W. HARGITT 
is associated in its nutritive relations with the direct activities 
of the tissue cells of the parent organism, yet in this particular 
species the egg certainly turns parasite, if not cannibal, and de- 
vours bodily the cells of either ectoderm or entoderm as may 
happen to afford it particular support at a giventime. And one 
finds in these growing ova of E. hargitti eggs literally loaded 
during most active growth with the engorged nuclei of tissue 
cells, the exact counterpart of those conditions found in Pennaria 
and Tubularia in which the growing eggs are similarly packed 
with the primordial ova of the ovarian tissues. 
In his earlier studies on heredity Weismann admits that germ- 
cells may be derived from somatic cells, e.g., (Essays on Heredity 
Eps 209): 
It is quite impossible to maintain that the germ-cells of Hydroids or of 
the higher plants exist from the time of embryonic development, as 
indifferent cells, which cannot be distinguished from others, and which 
are Only differentiated at a later period. Such a view is contradicted 
by the simplest mathematical consideration; for it is obvious that none 
of the relatively few cells of the embryo can be excluded from the 
enormous increase by division, which must take place in order to pro- 
duce the large number of daughter individuals which form a colony of 
polyps. It is, therefore, clear that all the cells of the embryo must for 
a long time act as somatic cells, and none of them can be reserved as 
germ-cells and nothing else; this conclusion is moreover confirmed by 
direct observation. 
In later discussing th's feature, while still contending that 
in most cases germ-cells arise early in ontogeny, Weismann is | 
yet compelled to admit that in Hydrozoa these do not arise till 
very late, and indeed in individuals of a later generation, (Evo- 
lution Theory, vol.1, p. 410). Notwithstanding this admission 
he still contends for his dogma of germinal continuity: 
Here the primordial germ cell is separated from the ovum by a long 
series of cell-generations, and the sole possibility of explaining the pres- 
ence of germ-plasm in this primordial cell is to be found in the assumption 
that in the divisions of the ovum the whole of the germ plasm originally 
contained in it was not broken up into determinant groups, but that a 
part, perhaps the greater part, was handed on in a latent state from cell 
to cell, till sooner or later it reached a cell which it stamped as a primor- 
dial germ-cell. Theoretically it makes no difference whether these 
germ-tracks, that is, the cell generations which lead from the ovum to 
