er 
310 
in variola inoculata from skin inoculation, where an eruption develops 
in from 70 to 80 per cent of the animals. 
The constitutional reaction in monkeys variolated upon the mucous 
membrane differs in degree from that in those variolated upon the skin. 
We do not find such an abrupt elevation in the body temperature, and 
malaise and anorexia are absent. It seems reasonable to suppose that 
this relatively slight constitutional reaction is conditioned by the physical 
conditions at the locus of inoculation. The initial lesion on the mucous 
membrane is practically an open wound from the beginning, and conse- 
quently the products of cell destruction and any toxins produced by the 
specific organism can readily escape. The systemic absorption from 
lesions on the mucous membrane must be quantitatively much less than 
from the lesions upon the skin. 
We are inclined to attribute the infrequency of the exanthem in this 
series of animals to physical conditions at the Jocus of the primary lesion. 
At the time of inoculation the amount of virus which enters and remains 
in the scratch must be notably less than when the skin is inoculated, 
owing to the fact that the surface inoculated is bathed with fluids and any 
exudation stream set up by the trauma of the inoculation would be 
assisted by the moist condition of the surface and the action of similar 
opposed surfaces to carry off the bulk of the virus. In these inoculations 
there can be no such flooding of the lymphatics about the scratch as must 
occur after similar inoculations of the skin. 
The type of disease produced by variolation upon the mucous mem- 
brane conforms in general to that which follows inoculation of the skin. 
The nature of the primary lesion and the time of occurrence of the 
exanthem relate the disease at once to variola inoculata. The absence of 
focal lesions in the bone marrow and testicle differentiate the disease from 
variola vera in man. | 
CONCLUSIONS. 
(1) Inoculation of the mucous membrane of the lip, the nose, or the 
palate of the monkey (M. cynomologus) with variola virus produces a 
disease which conforms to the type of variola inoculata. 
(2) The primary lesion on the mucous membrane is similar, cyto- 
logically and histologically, to that which follows variolation of the skin. 
(3) Cytoryctes variole, in both the protoplasmic and the nuclear 
phases, are present in the lesions. 
(4) Cytoplasmic forms of the parasite are found invading endothelial 
cells of lymphatics beneath the lesions of 5 days’ duration. 
5. ON THE OCCURRENCE OF VARIOLA VERA IN MONKEYS AND IN THE 
ORANG-UTAN. 
In the preceding sections we have shown that the monkey and the 
orang-utan react in a definite manner to inoculation with the virus of 
smallpox. This reaction consists in the development of a disease which 
