GERM CELLS ‘OF COELENTERATES 391 
of stages through the entire history of the egg. Furthermore, 
there is no division of the cell to form generations of oogonia and 
oocytes, but from the earliest stage found, up to the mature egg, 
it is the growth and development of a single cell. In other words, 
an individual cell (or half of a single.cell) of the entoderm trans- 
forms directly into a single mature egg without any divisions in 
the process, until the polar bodies are formed. 
Smallwood (’09) found in Hydractinia that egg cells are trans- 
formed directly without any immediately preceding cell divisions 
and C. W. Hargitt (’11) refers (p. 525) to similar occurrences in 
Pachycordyle and Eudendrium, and others: have found similar 
eases. The point here made is that the form under consideration 
shows, in a manner so clear and striking as to leave no doubt, that 
it is not possible to speak of a ‘continuity of the germ-plasm’ in 
the sense of cells early set aside and more or less carefully guarded 
from contact with, and participation in, the activities of the so- 
called somatic cells. For it is clearly shown that the egg cells 
arise from, and are a further development of, an individual 
(already differentiated) entoderm cell, which up to the time of the 
transformation was performing the same functions as its neigh- 
bors lining the coelenteric cavity. Here, somatic and germ cells, 
that is somato-plasm and germ-plasm, are one and the same 
thing. It is proper to speak of a continuity of germ-plasm in the 
sense that all cells in the body, germ cells and somatic cells, are 
descendents of the original fertilized egg cell; but no cell in the 
body appears to retain any initial peculiarity that does not also 
apply to every other cell. If it be objected that this removes from 
the concept ‘germ plasm’ the very thing that has characterized 
it, I can only reply that such is precisely the case; but from the 
evidence as presented in C. flexuosa no other conclusion can be 
drawn. The work of Goette (’07) and of others give the same 
results when they say germ cells may be formed from any ofthe 
developmental stuffs of the body. Jorgensen (’10) finds the same 
thing to be true in sponges and comes to the same conclusion. 
It is not necessary to insist that these conclusions be applied to 
all other groups of animals, for exactly the opposite conclusion 
has been drawn from the evidence shown in forms such as Ascaris, 
