Opalina, d11 
abnormal, though there is little to indicate that they are so. With 
them are often found clearly abnormal forms. Fig. 89 shows one 
such very stocky individual of O. caudata which had four nuclei 
each in a telophase stage of division. ‘’wo of these are seen in the 
figure in end view and so do not show that they are in mitosis. 
Fig. 90 shows an individual whose two nuclei have almost completely 
degenerated. I have found one individual of O. cntestinalis with ab- 
solutely no trace of a nucleus. These were clearly pathologic 
forms and not in any way comparable to the non-nucleated indivi- 
duals of Actinosphaerium, which Herrwie (1899) describes as reforming 
their nuclei from chromidia. Fig. 91 shows an O. caudata whose two 
nuclei are in a condition characteristic of multinucleated Opalinae, 
but very rare and I think abnormal in O. caudata. I have never 
found nuclei of this sort in O. itestinalis. 
In one lot of material of O. intestinalis from a_ fifty-four hour 
infection there were many individuals showing abnormal divisions 
similar to what Conn has described for the same species as budding ') 
(Figs. 228—235, Pl. XXV). When first seen these animals falsely 
seem to be zygotes in which fusion of the gametes is not yet com- 
plete. All the animals in this culture died within an hour. Fig. 229 
shows an individual just hatched from the cyst which lies collapsed 
near by. The little spine-like tip of the body shown in Fig. 230 
suggests that this individual was an imperfect microgamete (cf. Figs. 
163;: PH URX THs) 261) Pk XX). 
The abnormal nuclei in the six degenerating individuals of 
QO. obtrigona, referred to above, were very interesting and deserve 
further description. Figs. 99—101, Pl. XXI, recall some of 
LowentHar’s figures of nuclei of cysts of O. ranarum (Text 
Fig. X, b, page 280). Similar nuclei are quite usual in the 
full-grown forms of the multinucleated species, as well as in their 
cysts. The chromatin is found in two conditions 1) in a fine super- 
ficial net which slight nodal thickenings, this is hardly distinguish- 
able from the acrhomatic foam; and 2) in from two to six, or more, 
large disc-shaped or hemispherical masses pressed close to the nuclear 
membrane. Figs. 102 and 103 show somewhat similar superficial 
chromatin masses in which the chromatin is in the form of a darkly 
stained network with much lighter meshes. The difference in the 
appearance in the two sorts of chromatin discs in probably not 
wholly due to difference in staining. Very heavy staining and long 
1) Conn 1904, Figs. 14 and 15. 
