SOME PROBLEMS OF COELENTERATE ONTOGENY 53d 
‘mosaic work’! And what shall be said as to the existence of 
prelocalized germinal areasin such ova? Ihave searched through- 
out the phylum for ova having any semblance of such, but with- 
out evidence of its existence. It was thought for a time that 
Clava might be a case, but the most painstaking efforts to detect 
it were only negative. For a time Conklin believed he had 
found such in the ova of Linerges, and so pronounced; but his 
final utterance (’08, p. 166), recalls this: ‘‘The view expressed in 
my preliminary note on the development of Linerges, that the 
three layers of the egg give rise to the ectoderm, the entoderm, 
and the mesogloea is not confirmed by further study.” 
That there may be certain special distribution of egg material 
I have already shown in the case of several hydromedusae, but 
this is by no means implies that it is germinal in character or defi- 
nitely prelocalized. 
3. Amitosis 
In several earlier papers I found occasion to call attention to 
what seemed to be amitosis in cells during early cleavage. In 
several of these the evidence seemed direct and positive; in others 
the indications were somewhat general and indirect. The fact 
that several later students of cleavage in eggs of hydroids failed 
to confirm my results, while in the case of several others there has 
been very explicit confirmation, leads me to briefly review the 
matter as it appears at the present time. As I have elsewhere 
stated, the question of amitosis is purely one of fact. Whatever 
may be the implications of amitosis in its theoretical bearings on 
problems of heredity or otherwise, it must be evident that to 
attempt to discredit it on such grounds, or others of like nature, 
can only result in confusion worse confounded. One fact is Just 
as sacred as another, and just as much entitled to respect and 
consideration, and is bound sooner or later to be taken account 
of. The extreme attitude of Ziegler, Vom Rath, and certain 
other cytologists who would have us believe that amitosis is to 
be found only in senile or pathologic tissues, will have to be aban- 
doned as altogether unwarranted. Cytologists no less capable 
and conscientious, in growing numbers, accept amitosis as a normal 
