ieyist NATURAL HISTORY SOCIETY OF DUBLIN. 
specimens may require to be some time at rest upon the slide to induce 
them to project their pseudopodia, or it may require some happy com- 
bination of circumstances, as regards the illumination, to bring to view 
objects of so great tenuity and often of considerable transparency. The 
sarcode body is almost always more or less densely loaded with chloro- 
phyll corpuscles, sometimes amylaceous-looking granules, besides those 
colourless granules always noticeable in the Rhizopoda. I cannot say 
that I have been able to perceive a nucleus, the existence of which is 
queried by Carter; neither have I seen the contractile vesicles; and 
I imagine the temporary, somewhat conical projections of the “ lorica,”’ 
adverted to by Carter, may be due rather to mechanical disturbances of 
the globular form than to the action from within of any such pulsating 
movement. | 
In connexion with the Acanthosystis turfacea, I have noticed a 
somewhat remarkable circumstance, which is, perhaps, sufficiently 
curious to warrant description. What I allude to is its becoming, 
in some unexplained way, the nzdus for the development of the ova of 
a minute unascertained rotatorian; and I have noticed this circum- 
stance sufficiently often to show that it can hardly be considered as 
exceptional or unusual. One sees an Acanthocystis with a portion of 
the green body-matter still normal and healthy, and the rest of the 
space occupied by one or two colourless ova, or considerably more fre- 
quently one sees three such ova, and then the whole or nearly the 
whole of the body-matter of the Acanthocystis vanished. At first 
glance this might be thought to look like a developmental state of the 
Rhizopod itself. But on watching one showing this condition, before 
many hours may be seen the beginning of life in one of the ova before 
the rest; with amazement one watches, and presently there shapes 
itself out, not a young Rhizopod, but a little rotatorian (not unlike a 
Monolabis). By degrees the young animal assumes more and more of 
a definite figure, and, like all young rotatoria just ready to leave the 
egg, seemingly very impatient of confinement. By repeated knocking 
and shoving headforemost against the wall of the ovum, it ultimately 
succeeds in bursting the shell, and so it reaches to the cavity of the 
Acanthocystis. But it is still in prison there. Its narrow bounds, 
although soon, perhaps, likely to have the companionship of a couple 
more of its own species about to be born, would by no means satisfy its 
roving propensities. Now, the circumferential spicula of the Acan- 
thocystis cohere in some way into a tough strong stratum, making a 
kind of integument, which only gives way, upon force, by an irregular 
rent. One meets such remains of defunct examples of Acanthocystis 
now and again. Our young rotatorian now repeatedly dashes headlong 
against this remaining barrier between him and freedom. Well done, 
little fellow! He has burst his prison walls, and swims away rejoicing, 
and already begins to pick up his ‘‘crumbs” in the ocean (to him) upon 
the slide. I presume we must regard the rotatorian as wholly a usur- 
per here—in a great measure, a parasite. Can the germ of the rotato- 
rian grow at the expense of the material of the body mass of the 
