SMITH, ON MEASLED PORK. 5 



sitic worm, known to physiologists and anatomists as the 

 " Cysticercus cellulos(B." 



This worm, as it occurred in the muscle or flesh of the 

 pork supplied to me, consists of an external hag or cyst of 

 delicate rugose membrane, enclosing the animal of the Cysti- 

 cercus, retracted within its folds ; the space not occupied by 

 the worm being filled with a clear watery fluid. 



PI. II, fig. 1, represents the natural size of the " measles " 

 in fresh muscle ; fig. 2 the same in stale or salted pork ; and 

 fig. 3 the same fi'om fresh muscle, magnified 6 diameters. 



The animal of the Cysticercus, when withdrawn from the 

 cyst, Avithin which it lies invaginated, and curled up, in 

 all the specimens, consisted of a slightly enlarged head, 

 fig. 4 a, and a neck formed of numerous rings, fig. 4 b, 

 gradually enlarged into a bladder-like vesicle, fig. 4 c, 

 which constitutes the body of the worm. 



The neck and body of the Cysticercus are filled with a 

 mass of minute transparent bodies, which a fiu'ther examina- 

 tion leads me to regard as cellides discharging the function 

 of assimilation, i. e., converting the material endosmotically 

 absorbed by the cyst and bladder-like vesicle into the sub- 

 stance of the Cysticercus. The form of these cellides is 

 usually that of a flattened circular disc, and their average 

 diameter T^^-Vo^h of an inch, but neither their size nor form 

 is constant, some being linear, others irregular in outline, 

 and many not exceeding ^^V^^^^ of an inch in diameter."^ 



The head of the Cysticercus is provided, at its extremity, with 

 a circlet of about 24 booklets (fig. 5 a), immediately beneath 

 which are situated 4 circular organs, b, b, afterwards more 

 fully developed in the mature condition of the Cysticercus. 



The booklets, upon further examination with higher powers 

 of the microscope, arc seen to consist of a stem fixed in the 

 fiesli of the head (fig. 6 a), a barb (fig. 6 b), and a sickle-like 

 point (fig. 6 c). 



The Cysticercus, as above described, constituting the 

 "measles,^' is imbedded between the fasciculi of the muscle, 

 and occupies a chamber formed by the inflation of its cyst. 



Tlie cyst which in a fresh state fills the entire chamber, 

 on the death of the pig parts with its contained fluid, which 

 permeates the surrounding tissues. 



The chambers then collapse, and the muscle in consequence 

 becomes soft, and flabby to the touch. 



* [These elliptical bodies are composed in most part of carbonate of lime, 

 and would appear to be intended more for the purpose of giving greater 

 firmness or solidity to the part of the entozoon in which they occur than for 

 any other function. — Eds.] 



