THE RELATION OF DIET TO DISEASE 451 
arthritic cases occurred in Boatbilled herons {Cancroma 
cochlearia), fish-eaters. Our records show examples in 
Accipitres, Galli and Columbae, although the number of 
cases in the last order were few and slight in extent. This 
disease stands in close relation to diet, as it develops on 
generous protein food, high in nucleoprotein or hypo- 
xanthin, especially if this be associated with restricted 
activity. 
The carnivorous mammals lead in the disease of the 
thyroid glands. Thyroid disease occurs among the birds, 
but is equally distributed among the dietary groups. 
Thyroid activity has a marked influence on metabolism 
probably through the influence of the iodine-containing 
protein of its secretion. There are some experimental 
evidences in favor of a detoxicating function of the thy- 
roid, of which the following are quoted : (1) The effects of 
thyroidectomy are most marked in the carnivores; 
Herbivora are often capable Of several years of life with- 
out thyroid tissue; (2) administration of meat to 
thyroidectomized omnivores or herbivores caused a 
marked increase in all symptoms. The importance of 
the relation of the meat diet, detoxication and thyroid 
disease receives considerable confirmation from the fact 
that among the 1,860 mammalian postmortems thyroid 
disease occurred in 2.6 per cent, of all mammals, 94.9 per 
cent, of which were found in flesh-eating varieties. 
Wells (32) suggested that possibly this could be inter- 
preted as an indication that toxic materials found in the 
meat in the intestinal tract were, under normal conditions, 
detoxicated by the thyroid. Against a local neutraliza- 
tion, however, is the improvement following the 
administration of dried thyroid substance. The function 
is either neutralization of toxic substances or the stimu- 
lating action on intracellular metabolism, both of which 
might be called into play by an excessive protein diet. 
(32) Chemical Pathology, Philadelphia, 1918. 
