146 DISEASE IN WILD MAMMALS AND BIRDS 
some cases of ulcerative bronchiectasis occurred but if so 
they were not conspicuous enough to mention in the diag- 
nosis and in only two protocols do I find a discussion 
thereof, once in a monkey and once in a carnivore. All the 
cases of our records were diffuse ectasias, fusiform, or 
irregular and none of the distinct saccular variety. 
From the foregoing facts it would seem that in human 
cases more weight should be laid to the effect of the 
dilating power of coughing and its preparatory exertions. 
While I am aware that the comparative incidence of 
human and lower animal bronchiectasis cannot be based 
upon the meager figures at our command, these dilata- 
tions certainly can be expected in a general autopsy 
service more in man than in lower animals. Chronic 
bronchitis is relatively rare, aside from the verminous 
varieties. I have seen little retained exudate in the 
bronchi, probably because quadrupeds seem with ease to 
raise and swallow the secretions. Nor do animals give 
vent to paroxysms of coughing such as the human being 
feels forced to do. Suggestive deductions from these 
points are that inflammation is the principal factor in 
acquired bronchiectasis and that the retention of secretion 
with \aolent inspiratory efforts are potent in man for the 
dilatation of the tubes. 
The Lungs. 
The essential respiratory organ of the animal body, 
the lung, is all through this kingdom a structure intended 
to expose the blood to free or combined atmosphere in 
order to permit gaseous interchange, therefore being 
arranged so that there is a close apposition of the two 
factors, separated only by such cells and membranes as 
may be necessary to protect the circulation ; perhaps these 
anatomical elements possess at the same time some vital 
force to further the exchange of useful and useless matter. 
In the two classes under discussion there is no difference 
whatsoever in the primary factors of respiration albeit 
