THE COMMUNICABLE DISEASES 515 
external appearance and behavior, it naturally follows 
that early cases, possibly of an "open" or infectious 
character are still less likely to give evidence of their 
existence. This is well recognized by veterinarians as 
being true of cattle, but is perhaps less well known, or 
possibly admitted, by those who handle the very sus- 
ceptible monkey. 
Upon a visit to a foreign garden I was told that 
experience alone is sufficient to enable an observer to 
detect tuberculosis, and that the disturbance entailed in 
physical examination and tuberculin tests is preju- 
dicial to the well being of all varieties, but especially the 
delicate ones. I learned later that they had the disease in 
their exhibition cages all the time but decided to put their 
method to the test. Shortly after my return from abroad 
a splendid specimen of Grivet Monkey {Cercopithecus 
sah(Bus) was condemned by the tuberculin test. He was 
well studied by the superintendent and two very experi- 
enced keepers, all of whom pronounced him one of the 
finest specimens they had ever seen, and stated that he 
was behaving quite normally. Despite their protests he 
was sacrificed, tuberculosis with early cavitation being 
found in the upper lobe of the left lung. Incidentally 
vague physical signs were found by auscultation, but as 
the monkey was unruly and had long pectoral hairs little 
weight w^as placed on the observation. However, it is 
frequently possible to make very thorough physical 
examination of the lungs of the more tractable specimens, 
diagnoses of pneumonia and bronchitis being frequently 
made in this and other parks, so that treatment may 
be instituted. 
Importance of Transmission and Known Susceptibility. 
Some light upon possible reasons for the poor condi- 
tion of an individual animal is of course shed by a 
knowledge of the disease to which that particular variety 
is most susceptible, to which may be added the data 
