20 
Journal of Agricultural Research 
Vol. I, No. i 
Cobbold, for example, apparently studied only one specimen (imperfect), 
and Railliet seems to have had only one fully developed undegenerated 
specimen for critical examination. 
Up to the present time sheep measles have been reported from the 
following countries: England, Germany, France, Algeria, German South¬ 
west Africa, New Zealand, and the United States. 
In completing this brief critical summary of the literature, only a few 
words need be given concerning the morphology of the parasites. As 
already noted, morphological details have been omitted from most of 
the accounts given of the recorded cases. The measurements of the 
hooks given by Railliet and Morot correspond to Cysticercus ovis , as do 
Bongert’s measurements and photomicrograph. Maddox was the first to 
observe the mammillated surface of the caudal bladder, which, however, 
has not been recognized as a distinctive difference between C. ovis and 
C. ienuicollis , except by the present writer (i9o8d), and apparently has 
escaped attention from other observers. 
LIFE-HISTORY INVESTIGATIONS 
Under date of February 29, 1912, Dr. S. E. Bennett, inspector in 
charge at Chicago, Ill., reported to the Bureau of Animal Industry that 
a number of sheep carcasses had been found to be infested with measles, 
and under date of March 1 Dr. O. B. Hess, inspector in charge at Seattle, 
Wash., also reported the finding of measles in several sheep carcasses. 
Specimens were forwarded to Washington from both stations for labora¬ 
tory examination. The cysts in the specimens were all degenerate, but 
fragments of the caudal bladder of cysticerci were found, and in view of 
the presence of cuticular papillae, which are likewise present on the 
caudal bladder of Cysticercus cellulosae , and in accordance with the 
opinion of German meat-inspection authorities as to the identity of 
mutton cysticerci, the diagnosis of C. cellulosae was made. Shortly fol¬ 
lowing the first reports, information was received that out of 4,537 sheep 
slaughtered at Seattle, Wash., 79 carcasses were retained on account of 
measles, and that during a month at Chicago 224 carcasses were retained. 
With this information at hand it was immediately apparent that the 
diagnosis of Cysticercus cellulosae could not be correct, for the reason 
that C. cellulosae and its tapeworm stage, Taenia solium , are exceedingly 
rare in the United States. Probably not more than a dozen cases of 
pork measles are found annually at any of the large stations, where the 
number of hogs slaughtered amounts to hundreds of thousands. It was 
unbelievable that a parasite so rare in its usual host should be so common 
in sheep. A few days spent in studying numerous specimens obtained 
at the abattoirs in Chicago developed the fact that the sheep-measle 
parasite was certainly not C. cellulosae , though in certain characters 
they were very similar. In some details of structure the muscle cysticerci 
