518 DISEASE IN WILD MAMMALS AND BIRDS 
than one case occurs in the same enclosure containing 
groups of these varieties. Nor do animals in adjoining 
cages seem to ** catch " the infection. This observation 
does not suggest that any relaxation of hygiene need be 
allowed but probably it implies that not many bacilli are 
excreted by these animals ; they cough very rarely. 
Groups of ungulates (bison and deer) are often known 
to be infected but just how it has arisen is seldom clear. 
Transmission from monkey to monkey has been observed 
so frequently that it cannot be doubted, nor will anyone 
wonder at it if reflection is given to the close personal 
contact of these animals during their natural behavior. 
They huddle, pluck lice from one another, take food 
from the mouth of another, bite and perform many other 
actions greatly facilitating the transfer of any \'irus. 
Bacilli may also be disseminated by coughing, drooling 
and with the fecal discharges, for which latter there seems 
ample opportunity since a notable percentage of cases 
have intestinal lesions. Monkeys do not seem to raise 
sputum and expectorate it but they do eject saliva from 
their lips. 
Contraction of the disease from infected cages is be- 
lieved to have occurred at least once in our experience 
but the lesson of complete sanitary cleaning of the 
enclosure learned from that happening, seems to have 
enabled us to forestall its repetition. 
The Tuberculin Test. 
Tuberculosis presents the greatest single problem 
among the specific infectious diseases which the director 
of a menagerie must attempt to solve. Even though one 
may possess a knowledge of its zoological distribution, 
clinical characters and pathological effects, these are in- 
sufficient criteria for its detection at a stage when the 
animal might be saved by treatment or, what is most 
important, removed from its companions that they might 
be protected. To this end there remains but a single 
