Oct. io, 1913 
Cysticercus Ovis 
27 
of C. tenuicollis) survived until killed at the close of the experiment. 
All but one of the lambs (No. 2), which died 22 days after feeding, were 
examined post-mortem. 
Omitting this lamb from consideration, all of the lambs which received 
segments from the tapeworms produced by feeding muscle cysticerci 
showed cysticerci in their muscles when examined. Those found in the 
lamb which died 13 days after feeding were very small; those in the 
lamb which died 23 days after feeding were somewhat farther along 
in development, the beginnings of the head being already evident. 
Eighty-three days after feeding, the muscle cysticerci were found to 
have reached full development; some which had fully developed were 
already more or less degenerated, and some were found which had begun 
to degenerate before they reached their full development. In addition 
there were present live cysticerci which had not yet fully developed. 
The lambs which had been fed segments of Taenia hydatigena showed a 
few Cysticercus tenuicollis , most of which were degenerate. In both 
animals there were small degenerate cysticerci on the liver. There were 
no visible lesions of the liver in the lambs fed segments of T. ovis. No 
C. tenuicollis was found in any of the lambs fed segments of T. ovis , and 
no C. ovis in the lambs fed segments of T. hydatigena. The check lamb 
showed neither C. tenuicollis nor C. ovis, and neither of these parasites 
was found at the post-mortem inspection of the remainder of the lot 
from which the experiment sheep had been selected. 
Since these experiments show that muscle cysticerci in sheep resembling 
Cysticercus cellulosae and corresponding to the form described by Cob- 
bold as C. ovis develop into tapeworms when swallowed by dogs, it has 
been definitely proved that these cysticerci are not C. cellulosae. The 
adult of C. cellulosae (Taenia solium) does not occur in dogs; moreover, 
the tapeworms which were produced in the dogs are quite different from 
T. solium. Furthermore, the experiments prove that the muscle cysti¬ 
cercus and its adult stage are specifically distinct from C. tenuicollis and 
T . hydatigena . It appears that the ingestion of one or more gravid 
segments of T. ovis is likely to prove fatal to sheep. 
Attempts to produce tapeworms in man by feeding mutton cysticerci 
failed. On three occasions live mutton cysticerci were swallowed by the 
writer, a total of 10 cysticerci being ingested. No evidence of tapeworm 
infestation has since appeared. This experiment tends to prove that 
Cysticercus ovis is not transmissible to man. 
SYNOPSIS OP hWH HISTORY 
The adult of Cysticercus ovis is a tapeworm ( Taenia ovis) which occurs 
in the intestine of dogs. Since the parasites which live on dogs as a rule 
also thrive on wolves, and, since coyotes and other wolves frequently 
