Opalina. 215 
macrogametes and other small forms from the tadpole, except possibly 
the microgametes, and also in the smallest forms found in the spring 
in the rectum of the frog. I regret that my notes do not say as to 
the presence of the ectosare spherules in the microgametes of 
O. dimidiata and I do not remember with certainty, though I think 
they are present and of good size in this species as in the micro- 
gametes of O. intestinalis and O. caudata. 
It is not easy to be certain who of the students of the Opalinae 
have seen the ectosare spherules, for, excepting by Licrr & Dusosca 
(19046) for O. saturnalis, they have not been figured or clearly 
described. TOnniGEs (1898) describes for O. ranarum certain greenish 
granules, disc-shaped, elongated, or of irregular form, and varying 
in size. He says that in most individuals they lie exclusively in 
the endoplasm and goes on to describe at considerable length their 
minute structure. In the main his description applies surely to 
what I have called endosare spherules (Mercatr 1907 a), but the 
greenish color he ascribes to these is characteristic of the ectosarc 
spherules. TOnniGEs has not distinguished between the two kinds 
of spherules and it may be that the greenish color of the outer 
ones has been ascribed by him to them all. Contre & Vanry (1902) 
have evidently not distinguished the ectosare spherules. NeErzEs- 
HEMMER (1906 and 1907) describes remarkable phenomena connected 
with certain disc-shaped spherules. I am not sure I understand 
correctly his description, but it seems to apply to the larger ecto- 
plasmic spherules and not to the smaller sort of spherules which lie 
in the endoplasma. He says that these disc-shaped bodies change 
into spherical or ovoid spherules into which the reproductive chro- 
midia migrate, each spherule with its chromidia constituting a new 
reproductive nucleus in which the spherule furnishes the achromatic 
portion and the chromidia the chromatic portion of the new nucleus. 
The conditions in O. intestinalis previous to and during the spring 
sexual reproduction preclude any such interpretation, useless O. ra- 
narum, upon which NeresHEIMER worked, is fundamentally different 
from the binucleated species. Opalina ranarum is a far less favorable 
species than the binucleate forms for the study of the ectosare 
spherules, for in O. ranarum they are not only proportionally but 
actually much smaller. 
Endosare. 
The endosarc of all the species of Opalina I have studied shows 
usually a finely granular and fibrous appearance in which the real 
