SOME PROBLEMS OF COELENTERATE ONTOGENY 539 
These several series of facts afford, as I believe, very strong 
confirmation of my own results as related to Eudendrium, Pen- 
naria and Clava. They are also further supported by interest- 
ing results described by Young (’08) in connection with the ‘ His- 
togenesis of Cysticercus pisiformis.’ In this paper is found the 
somewhat radical suggestion that cells may arise de novo, from a 
‘eytoblastema,’ much as held by Schwann long ago. 
It is not necessary to review this phase further than to point 
out its relation to a similar suggestion made by the writer con- 
cerning a somewhat similar origin of cells after nuclear fragmen- 
tation in both Eudendrium and Clava. Several of Young’s 
figures are strikingly similar to those given in connection with 
Kudendrium, 
Another most interesting confirmation of my results is to be 
found in the account of Brooks and Rittenhouse (’07), of the 
development of Turritopsis. In this case both mitosis and ami- 
tosis are found occurring ‘simultaneously in the different cells 
of the segmenting egg.’ The varying size of the amitotic nuclei 
and their reticular structure, confirm with utmost exactness my 
earlier accounts. Furthermore, the association of amitosis with 
an approach toward syncytial conditions also resembles the con- 
dition in Eudendrium, as does also the metabolism associated 
with yolk digestion. I cannot agree, however, with the authors 
that there is any such relations involved in any of these processes 
as would bring them into conformity with the theory of Flemming, 
Ziegler, and others, that they presage degenerative ends. On 
the contrary, they seem to me to be most intimately associated 
with the intense metabolism and rapid growth of histogenesis. 
It remains briefly to refer to phases of nuclear behavior so 
characteristic in the cleavage of Pennaria, and to a less extent in 
Clava. Among these are such features as the highly vesiculate 
aspects of the nuclei during early cleavage, and the equally anom- 
alous features of clavicular, reniform and dumb-bell shaped nuclei. 
These facts have been very abundantly confirmed by the several 
researches of Hargitt, Smallwood, and Beckwith, already cited. 
Their interpretations, however, differ very widely from my own, 
and with plausibility and force. At the same time I fail to per- 
