32 
liver of the white rat, although several hundred ova were 
fed. This does not augur well for our plans, which were 
to so heavily infest the common rat that he might be 
killed. This would give us an opening for considering 
the advisability of exterminating, at least locally, this 
pest. 
Pneumonyssus foxi, — We have found a second instance 
of this Arachnoid parasite of the lungs in a rhesus monkey. 
I have identified it by accepted taxonomic methods as 
the same in all respects as that mentioned in the 
Report for 1916, page 38. It may be recalled that the 
new species, named after Dr. Herbert Fox, was described 
from this Laboratory. 
Strongyloides in Primates. — The young Orang Sylvia 
has had several attacks of pemphigus (a blistering skin 
disease) during the past two years, and on a routine 
examination of everything readily accessible Strongyloid 
worms were unexpectedly found in her feces. Her cage- 
mate, Villa, is not infested nor is the Chimpanzee Mimi; 
but the Chimpanzee Johanna in the nearby cage does 
yield the same worm, and in much larger concentration.' 
They are microscopic in size, and to casual examination 
are the same as human Strongyloides stercoralis. It 
would require minute and painstaking examination to 
settle this point. They are of questionable pathogenicity 
for human beings in connection with Cochin-China 
diarrhoea and certainly do not appear to be pathogenic 
for Johanna, who enjoys perfectly good health. There is 
little ground, therefore, for a belief that they are causing 
the pemphigus in Sylvia, and the interest in the finding 
resolves itself into whether this species is identical with 
the human, is transmissible between man and ape, and 
whether the ape can be looked upon as a possible 
Strongyloides carrier. 
Respectfully submitted, 
FRED D. WEIDMAN, 
Acting Pathologist. 
