322 DISEASE IN WILD MAMMALS AND BIRDS 
ment and disease may be g-reater than the excess work 
occasioned by the mere physical bulk of the enlarged 
gland in the neck would seem to warrant. A detoxicating 
function has been ascribed to the gland, but Murray dis- 
credits this on the ground that congestion occurs in 
infectious disease of warm blooded animals but not in 
snakes. He thinks the gland more likely stands in some 
connection with the thermoregulatory mechanism. 
It is evident from the foregoing that the thyroid is 
closely related to protein metabolism, and that this is in 
some way connected with the ability the body possesses to 
use iodine in the food if it can get it. Feeding of meat to 
fish was found by Marine to increase the size of the 
thyroid. With all this in mind it is not astonisliing that 
two-thirds of our cases of thyroid abnormalities were 
found in the order Carnivora. 
The anatomical changes of the human thyroid that 
precede or accompany the various clinical pictures cannot 
be said to be uniform to a degree that one can even 
approximately predict in every case what will be found 
at operation, at autopsy or by the microscope. Further- 
more, much discussion has existed upon the importance 
of the several changes, the association with clinical phe- 
nomena and the nomenclature. I shall not enter the 
academic discussion with our material because so much 
has depended, in human medicine, upon symptoms, signs 
and chemistry — data that we cannot adduce. Upon many 
occasions I have seen animals with very e\ddent goitres, 
but have not been able to detect bulging of the eyes or 
especial nervousness. One striped hyena carried his 
mass for several years. It swelled up occasionally and 
seemed to cause dyspnoea. At one examination of the 
beast, to see if anything could be done for him, a large 
cyst broke under the examining hand, whereupon a deep 
inspiration was heard and rehef was apparent. This 
handling was repeated twice, these times Avith the pur- 
pose of breaking cysts and when this was successful 
