1 8 Journal of Agricultural Research voi.i,No.i 
Not only have observers failed to give sufficient evidence that the 
mutton cysticerd in any case exactly agreed in morphology with Cysti- 
cercus cellulosae or C. ienuicollis , but they have also failed to produce 
experimental proof to support their identifications. C. cellulosae has 
never been produced experimentally in sheep by feeding Taenia solium 
eggs (Teuckart, Kiichenmeister, Perrondto); nor, vice versa, has T. solium 
been produced in man as a result of ingesting mutton cysticerci (Chatin, 
Ransom 1 ). 
There is also no good evidence that Taenia hydatigena has ever been 
obtained as a result of feeding the mutton cysticercus to dogs. It is 
true that Chatin states that such is the case, but the evidence that the 
tapeworms were identical with those belong¬ 
ing to Cysticercus tenuicollis consists simply 
in ChatnTs affirmation that they were the 
same, and there is no objective evidence at 
all to support this view. It also should be 
noted that no one has shown that segments 
of T. hydatigena , when fed to sheep, will pro¬ 
duce muscle cysticerci. Leuckart, Kiich- 
enmeister, and others have found only C. 
tenuicollis as a result of such experiments. 
Cobbold’s opinion that Cysticercus ovis 
is the larva of a human tapeworm, the so- 
called Taenia tenella , has never had any 
supporting evidence and, of course, is now 
entirely discredited. Cobbold, however, it 
is interesting to note, was quite correct in 
another opinion which he at one time held—namely, that it is probable 
that the adult of C. ovis occurs in one of the carnivora. 
Most of the records of muscle cysticerci in sheep are based upon iso¬ 
lated cases in which the parasites have usually been more or less degen¬ 
erate. Thus, Cobbold noted the presence of degenerated cysticerci in 
mutton on several occasions and described Cysticercus ovis on the basis 
of a single specimen (fig. 2) which had lost the caudal bladder before it 
came into his hands. Maddox described C. ovipariens (figs. 3 and 4) on 
the basis of one degenerated cysticercus. The number of cases seen by 
Mobius, reported by Kiichenmeister, is not stated. Chatin apparently 
saw muscle cysticerci on several occasions, and some of these evidently 
were alive and undegenerated. Morot refers specifically to five cases 
and refers to an indefinite number of others, in all of which the parasites 
were degenerated and were recognized as cysticerci only from the char¬ 
acter of the cysts. Railliet and Morot reported one case of a single, 
apparently undegenerated cysticercus in the heart of a sheep, and refer 
Fig. 2.—Cysticercus ovis: Head and 
neck, X 30. (After Cobbold, 1869a, p. 
30, fig. 2.) 
1 For an account of the present writer’s experiments, see pp. 21-26. 
