CYSTICEECUS CELLULOSE, AS POUND IN THE MUSCLES OF THE PIG. 117 
circular or oval spaces, which might be taken for nuclei or nucleoli. These collections of 
corpuscles make up nearly the whole of an animalcule, and they frequently give to it a 
lobulated and sometimes an obscurely annulose appearance. See Plate XI. fig. 2. 
The entozoa, as long as they remain in the primary fasciculi, retain all those cha- 
racters which have so far been described, but these characters gradually disappear after 
they have broken away from the cavity of the sarcolemma, and gained access to the 
spaces between the muscular fibres. 
In this new situation they gradually lose their former membranous clothing studded 
with ciha-like fibres, which can occasionally be seen partially deprived of its corpuscular 
contents, though sufiiciently perfect to admit of demonstration. See Plate X. fig. 16. The 
reniform corpuscles before aggregated together in circular groups now gradually lose 
their distinctness of outline, and imperfectly coalesce into confused ill-defined masses, 
haviug an oily aspect, so that, if in this state one of these vermicules be crushed under 
the microscope, amorphous oily and granular matter will be seen to have escaped from 
it, similar to that contained in the ventral part of the adult animal. Here, too, the 
restraint to the lateral growth of these entozoa being very much diminished, their breadth 
increases rapidly, and they present globular projections extending out very irregularly 
from their sides, giving them an irregular figure. See Plate XI. fig. 2. These projections 
gradually take on the form of those which were described on the ventral part of the 
perfect entozoon. The largest of the entozoa which I have seen in this stage is about 
j^th of an inch in length, and ^th in breadth. 
The next facts requuing especial notice, are those connected with that stage of develop- 
ment which takes place after the animalcule has become surrounded by an adventitious cyst. 
The first indication of the formation of such a cyst is, the turgescency of the capil- 
laries, or some of the smaller vessels in the vicinity of one or more entozoa. Granular 
bodies, exudation corpuscles, and fibres of different shapes next make their appearance. 
These at first only partially obscure the entozoon, but afterwards completely conceal it. 
When the cyst is first formed, the animalcule can, by a good light and careful exami- 
nation, be obscurely seen within it, and by dissection under the microscope it can be dis- 
lodged. See Plate XI. fig. 1, which is an accurate representation of one of these animals 
folded up in its cyst. Thus folded up, it measures i^th of an inch in length. 
Plate XI. fig. 7 shows a Cysticercus removed from its adventitious cyst. It has still 
somewhat of the folded character of the preceding specimen. This is yth of an inch in 
length, and aVth in breadth. The interior of a cyst being smaller than the animalcule 
contained therein, it naturally follows that during its growth one portion must be folded 
over another. By this means it is adapted to the confined locality in which it is lodged 
during the period of its development. Hence the ventral portions of all Cysticerci 
are, when first taken from their cysts, very much plicated ; but these plicae disappear 
after the ventral sac has become distended with the fluid brought into contact with its 
surface. 
Up to this point of the development of the Cysticercus, it is a simple cyst growing by 
MDCCCLVII. K 
