Oct. 10, 1913 
Cysticercus Ovis 
17 
generalized coenurosis, there is no definite conclusive evidence that more 
than one species of parasite is concerned in sheep measles; hence the 
presumption is that the muscle cysticerci reported from sheep *all belong 
to a single species. Taking into account the fact that it has now been 
proved by experiment that muscle cysticerci in sheep develop into tape¬ 
worms distinct from either Taenia solium or T. hydatigena , it is quite 
clear that none of the observers reporting muscle cysticerci in sheep has 
given sufficient evidence to show that the parasites in any instance were 
Cysticercus cellulosae , as they were held to be by some, or C. ienuicollis , as 
they were held to be by others, and not in all cases, C. ovis. Commonly 
the only evidence to support the observer’s identification is a statement 
that the parasite showed the 
characters of C. cellulosae ( 01 1, 
Armbriister, Colberg, Rick- 
mann, Herter) or C. ienuicollis 
(Chatin, Glage). In a few 
cases measurements of the 
hooks have been recorded, but 
these apply equally as well or 
better to C. ovis than to C . 
cellulosae or C. ienuicollis. 
Rongert’s report is of special 
interest in this connection, as 
he gives a photomicrograph of 
the hooks (fig. 1), comparison 
of which with the hooks of 
C. cellulosae shows that the 
hooks agree imperfectly, thus 
demonstrating the incorrectness of Bongert’s positive opinion that the 
parasite was C. cellulosae. The opinion formerly held by the present 
writer (i9o8d) that certain partially grown muscle cysticerci with hooks 
not yet fully developed which had been found in a sheep were C. cellu¬ 
losae on account of the presence of certain characters also found in C. 
cellulosae is likewise seen now to be quite erroneous. 
Railliet and Morot noticed that the hooks of a cysticercus resembling 
Cysticercus cellulosae from a sheep heart, though agreeing fairly well in 
size with C. cellulosae hooks, as shown by the measurements which they 
give, corresponded closely in form to those of C. ienuicollis . They 
accordingly so identified the cysticercus, at the same time, however, 
calling attention to the fact that the hooks are fewer in number than is 
usual in C. ienuicollis and that they are smaller, differences possibly to 
be attributed, according to their view, to the location of the parasite in 
the muscles instead of in the serous membranes. It is quite probable— 
in fact, not to be doubted—that the parasite in this case was C. ovis. 
Fig . 1.— Cysticercus ovis: Hooks, X 2 75. ( After a photomi¬ 
crograph by Bongert, 1899a, fig. 3.) 
