252 
body, at the period when the two chambers were not sepa- 
rated ; the other, posterior, embraces the larger part of the 
body of the cell (fig. 26 and following). It is remarkable 
that from the very commencement of the development of the 
protoplasmic filament on the surface of the “ generating 
cytod,” its free end was more charged than the rest of the 
body with opaque granulations. The cephalic extremity or 
“ anterior compartment” of the body of the adult Gregarina 
was already indicated. 
The partition between the two chambers which is in con- 
tinuity with the hyaline protoplasm of the periphery of the 
body differentiates itself little by little as it gets rid more and 
more completely of molecular granulations. 
Another modification which manifests itself in the con- 
stitution of the body of the Gregarina is the more and more 
complete delimitation of the most external portion of the pro- 
toplasm, which soon appears under the form of a membrane 
with double contour. ‘This membrane, which becomes more 
and more distinct, can be compared to the cuticle of the 
Infusoria, and, consequently, may be distinguished as the 
cuticular membrane. 
At the same time as the body elongates, it broadens notably, 
and the quantity of semi-fluid granular protoplasm which 
fills the greater part of the sac augments rapidly whilst the 
external protoplasmic layer, always hyaline and resistent, 
augments but slightly in thickness. 
The nucleus takes on a perfectly regular oval form; it en- 
larges at the same time as the cell, and it surrounds itself with 
a membrane, the presence of which, indicated by a double 
contour, can be demonstrated by making the nucleus submit 
to a transverse pressure. When the pressure has attained a 
certain degree of intensity, the nuclear membrane becomes 
rent (figs. 28 and 29). 
Ihave not recognised in the young Gregarine the suc- 
cessive disappearance of the nucleoli, so easy to observe in 
the adults. In the young Gregarine the nucleus never 
encloses but a single large nucleolus, in which very generally 
is observed a small vacuole. 
To complete this work it is necessary to compare the 
observation which I have above recorded with the most recent 
researches, of which the lower organisms have been the 
1 Since the publication of my first work on the Gregarina of the lobster 
(this Journal, January, 1870), where I announced for the first time this fact of 
the successive disappearance and reappearance of the nucleoli in the nucleus 
of a cell, M. Svierczweski, Assistant in the Physiological Laboratory at 
Kiew, has made known analogous facts observed by him in the ganglionic 
cells of the frog.—Centralblatt fir die M. W., 1869, No. 41. 
