270 M. M. Mercaur 
granules of other Cilata. But one notes a decided difference between 
the two. In Opalina the chromatin spherules are formed and dis- 
solved in the course of every cell division, while in most of those 
Ciliata which have been most carefully studied the macronucleus 
dissolves and is reformed only during or after conjugation, or under 
conditions of nutrition which often induce conjugation. In Hopli- 
tophrya uncinata, a probable near relative of Opalina, the macro- 
nucleus is very often found fragmented into granules or groups of 
granules which are scattered through the cell (Text Fig. VIII, C). 
One cannot believe that this fragmentation is usually connected 
with conjugation. I have not followed the fate of the scattered 
granules in Hoplitophrya uncinata, nor have I as yet had time to 
study carefully the abundant refractive spherules in the endoplasm 
of this species. They seem to be formed in the macronucleus and 
also in the scattered fragments of the macronucleus when this 
breaks to pieces (Text Fig. VIII). They do not react to mtra vitam 
stains exactly as do the endoplasmic spherules of Opalina, yet they 
are probably of a generally similar nature. The apparent connection 
of refractive spherules and macronucleus in Hoplitophrya uncinata, 
and the frequent fragmentation of the macronucleus, make this 
species a peculiarly favorable one for the study of the refractive 
spherules and their relation to the macronucleus. I hope soon to 
give the matter further study. The scattered macronuclei of Loxodes 
rostrum (JosEpH 1907) are perhaps comparable to the scattered groups 
of macronuclear granules seen in Hoplitophrya. 
The relation of the refractive spherules in the endosare to the 
chromatin spherules in Opalina is not fully established. The resem- 
blance between the two in their staining reactions is not a demon- 
stration of their relation, but it does suggest that the substance of 
the chromatin spherules may find its way into the endoplasmic 
spherules. This, is rendered still more probable by the fact mentioned 
that in Hoplitophrya apparently similar refractive spherules arise in 
the macronucleus and in the scattered groups of macronuclear gra- 
nules when the macronucleus fragments. 
Refractive spherules somewhat comparable to those in the endo- 
sarc of Opalina are not rare among the Cuiliata, Nyctotherus and 
several species of Balantidium, present in the same hosts with 
‘Opalina, have many such refractive spherules in their endoplasma, 
which, however, seem always to stain darkly with iodine. They 
are not composed of true glycogen but are apparently paraglycogen 
of a somewhat different nature from that in the spherules of Opalina. 
