118 
ME. EAIXET ON THE STEECTHEE AND DEYELOP:iIENT OF THE 
the assimilation of fluid imbibed equally by every part of its surface, no one part dif- 
fering sensibly in its structure from another. No portion of this surface presents any 
indication of incipient booklets or suckers. There is nothing either on its surface or in 
its interior analogous to the structure of an ovum. Nor is there any other anatomical 
character which would raise its organization above that of a simple acephalocyst. How- 
ever, this so exactly resembles in its structure that of the ventral portion of a perfect 
Cysticercus, that it is impossible to doubt their identity of character. Its size, too, is not 
much beneath that stage where the suckers and booklets first begin to present obscure 
indications of the part they are about to occupy. I may obsene, moreover, that this 
form, and all the preceding ones, together with perfect Cysticerd provided with the 
regular number of booklets and suckers, can, in many specimens of diseased muscle, all 
be found intermixed together in a space not exceeding a square line. 
The dimensions of that form of Oysticercus in which there are obscure, though suflS.- 
ciently certain, indications of the site about to be occupied by the neck and suckers, are 
about iwth of an inch in length, and i^th in breadth. See Plate XI. fig. 8. 
The first indication of the addition of the neck with the suckers and booklets to the 
ventral part of a Cysticercus, is the appearance about its centre of a shghtly raised body, 
depressed in the middle, with longitudinal folds proceeding from each side of it towards 
the poles of the ventral cyst, appearing as if at this part the parietes of the latter had 
been drawn inwards. See Plate XI. fig. 8. On two sides of this hollow there ai'e dark 
transverse lines, rather more distinct on one side than on the other, indicating the com- 
mencement of the transverse rugae of the neck, mentioned in the description of tliis part 
in the perfect animal, in which the laminated earthy bodies are contained. About the 
central part of the cervical projection there is an ill-defined oval space, ha’sing a granular 
appearance, and containing some minute spherical particles of a dark colour, consisting 
apparently of a highly refractive material. See Plate XI. fig. 8. In this condition of the 
entozoon there is nothing in this space which has the slightest resemblance to the parts 
which are there about to be developed, namely, the booklets, suckers, and eaidhy concre- 
tions; and it is only by the comparison of these obscure appearances with the other- 
specimens in which the development of the booklets is a little more advanced, that their 
true signification can be learned. See Plate XI. figs. 10 and 12. 
Of these parts I will first describe the development of the booklets, these being the 
most remarkable and characteristic organs of a Cysticercus. 
By comparing the preceding specimens with one hr which some of the booklets ai-e in 
progress of development, and sufficiently advanced in then- formation to leave no doubt 
of their real nature, it will be seen that the highly refractive globular pai’ticles seen in 
Plate XI. fig. 8 are portions of the material of which the booklets are composed. The entii-e 
number of these organs is not in progress of formation at the same time, but only about six 
are being developed at once, and when these are nearly completed, others make theii- 
appearance. The primary condition of one of these organs is very remarkable, consisting 
merely of a confused and irregular group of very bright particles of a pale straw-coloiu’. 
