194 
POPULAK SCIENCE EEVIEW. 
vesicles, and food vacuoles are no longer traceable ; circulation 
ceases, and the more conspicuous phenomena appear to be 
limited to the enclosure of one or more frustules of Diatoms 
(fig. 4) within the granular sarcode, the whole being contained 
within a defined capsule. This state is followed by the segre- 
gation of the sarcode granules into spherical masses (fig. 5, s), 
sometimes as many as eight in number, but usually not more 
than three or four. These granules appear to be identical 
with others which Dr. Wallich had previously observed and 
described under the name of sarcoblasts, and which evidently 
consist of the old sarcode of the Amoeba, revivified, after a 
fashion seen amongst other organisms, by passing through a 
temporary stage of rest. But, before tracing the further 
development of these bodies, we must examine the growth 
of another class of sarcoblasts, whose origin is altogether 
different. 
Both Dr. Wallich and Mr. Carter have noticed a segmenta- 
tion of the nucleus. The result of some of these processes of 
segmentation is very doubtful, but in others it has been the 
wholesale production of broods of young Amoebae. Mr. Car- 
ter found the nucleus, in one variety, to subdivide, until it 
consisted of more than seventy segments (fig. 2, s) of yellowish 
plasma, each being about Y s Vo th of an inch in diameter, the 
original nucleus, from which they sprang, having been about 
y-aVoth of an inch in size. Dr. Wallich has never succeeded 
in observing this wholesale segmentation of the nucleus. He 
has found that the nucleus and its capsule become segmented 
together up to a certain point ; but, according to his observa- 
tions, a limit is soon reached, beyond which no further fission 
takes place. When fission has ceased a new action begins, 
which results in the production of a number of sarcoblasts 
within the body of the nucleus. There is some ground 
for doubting whether these two writers have had the op- 
portunity of observing the same phenomena, which may 
account for the present disagreement of their conclusions. 
Mr. Carter says that each of the germs or sarcoblasts which 
he has seen formed by the segmentation of the nucleus is sur- 
rounded by a distinct capsule. Dr. Wallich recognizes the 
existence of the capsular covering of his segmented nuclei, 
wherever he has seen such ; but these have always been few 
in number, and altogether different from his sarcoblasts, 
which never exhibit such a covering. Of course a discrepancy 
of this kind between the observations of two such practised 
observers requires further research for its elucidation. But 
looking at the Protean nature of these organisms, it is 
more than probable that not only these variations exist in 
their reproduction, but that many others remain to be dis- 
