318 GC. CLIFFORD DOBELL. 
mecium (Calkins and Cull, ’07) and probably for other 
Infusoria. This kind of hermaphroditism must be a very deep- 
rooted phenomenonif we agree with Schaudinn and his followers 
(e.g. Prowazek) that sexuality is a fundamental attribute of 
living matter—a belief which I by no means share. 
A view similar to that of Schaudinn regarding the trypano- 
some cell has been put forward by Salvin-Moore and Breinl 
(07), who suggest that the nucleus and blepharoplast are 
differentiated gamete nuclei in one and the same individual. 
With Minchin (08) I believe that this view is “ far-fetched 
and misleading in the highest degree.” 
In connection with this matter mention may be made of a 
very remarkable binucleate protozoan, Amoeba diploidea, 
recently described by Hartmann and Nagler (08). The 
animal contains two nuclei, lying side by side, which a study 
of the life-cycle has shown to be the two gamete nuclei, 
which have not fused, from a previous conjugation. Fusion 
to form a zygote nucleus only occurs before the next conjuga- 
tion. We have here an organism in which the “paternal” 
and “ maternal’? chromatin remain separate all through the 
vegetative existence. Truly this is a most extraordinary state 
of affairs. It appears that A. diploidea is formed from 
two incompletely fused organisms, just as A. binueleats 
is formed from two incompletely divided ones. 
Finally, I will summarise the conclusions to which the 
foregoing considerations have led me. They are that the 
facts relating to chromidia are not yet sufficiently strong to 
bear the weight of the binuclearity hypothesis which rests 
upon them: that, therefore, this binuclearity hypothesis, 
however suggestive it may be as a working hypothesis, is 
far from being a “law,” as some would have it called: and 
that the tropho-kinetic binuclearity hypothesis is equally 
unworthy to rank as a cytological truth. he real signifi- 
cance of chromidial structures has been greatly distorted by 
viewing them from a theoretical standpoint. 
The most important inference, however, is that we require 
