388 GEORGE T. HARGITT , 
entoderm. In the ectoderm of this region no cells were found 
which looked at all like those figured, or any others that had any 
of the characteristics of germ cells, so it is certain that we have an 
entodermal origin of the egg cells. Goette (’07) found also that 
the eggs of Campanularia flexuosa which he examined, as well as 
those from most other campanularian hydroids, came from the 
entoderm and from the entoderm alone. He was not able to 
determine whether in this case the cells came from a single trans- 
formed epithelial cell as he had found in some hydroids or from 
the basal half of a divided epithelial (entoderm) cell as he found 
in other cases. Figures 3 and 4, especially the former, leave no 
doubt that an entodermal cell divides, the basal half forming the 
egg cell. Figure 2, however, seems to suggest the transformation 
of a single entodermal cell into an egg cell. There is no reason 
why both methods may not be active; certainly after it has been 
found, as Goette did, that some hydroids produce germ cells from 
ectoderm or entoderm indifferently, it might be expected that 
some would produce germ cells from entire or from half-cells 
indifferently, and this I believe to be the case in Campanularia 
flexuosa. 
The place of origin of the egg cells of the hydromedusae, once 
of great interest, has ceased to have very much importance. 
Weismann (’83), in his actual observations, found evidences of 
some germ cells arising from the ectoderm and others coming 
from the entoderm. (His statement on p. 145 concerning Cam- 
pularia flexuosa, that in the ectoderm there are cells which appear 
similar to the youngest egg cells, is not correct for the material 
which I have studied.) But later, especially in his volumes on . 
Evolution (’04) he refers the origin always to the ectoderm, and 
if they are not actually to be distinguished there, says they must 
at any rate originate there and later migrate into the entoderm 
where they become demonstrable as egg cells. Entirely aside 
from the theoretical importance which he claims for the place of 
origin and the subsequent migrations, views long since shown to 
be without any firm foundation or real significance, it is interesting 
to see the many cases where an undoubted origin from the ento- 
derm is demonstrated. C. W. Hargitt (06) showed in Clava 
