INFLUENCE OF CLIMATE, ETC., ON THE DISTRIBUTION & 
CHARACTER OF DISEASE. 693 
others report it very rare, although other practitioners report a 
more frequent occurrence. 
In Alabama, Dr. Cary reports the affection frequent and 
acute, but in general the disease seems not very common in 
the South. 
The disease occurs most frequently in the states bordering 
upon the Ohio River and upon the Mississippi River above its 
junction with the Ohio, reaching its greatest prevalence in the 
United States and probably in the world in Illinois, Iowa and 
Missouri. In more northerly states it tends to disappear so that 
Dr. Lyford, of Minneapolis, sees it largely in imported horses. 
As the high semi-arid country east of the Rocky Mountains 
is approached, the disease becomes far more rare and less dan¬ 
gerous, yielding readily in most cases to care and treatment. So 
in Nebraska and North Dakota, Drs. Stewart and Hinebauch re¬ 
port it very rare and mild. 
Reaching a still greater altitude with less rainfall and hu¬ 
midity the disease vanishes as we approach the Rocky Moun¬ 
tains to reappear again at a few of the lower altitudes along 
the Pacific Coast. 
This disease has no known parallel in geographical distribu¬ 
tion. It vanishes wholly in those regions where tuberculosis 
and tetanus cease to exist but prevails to its greatest extent in 
regions where the latter are comparatively rare, and in turn it 
becomes rare where tuberculosis and tetanus prevail most fre¬ 
quently and severely. 
The etiology has been explained by some teachers and wri¬ 
ters apparently to their entire satisfaction. I was taught that it 
was largely hereditary and that the shining example of this was 
to be found in the progeny of the famous blind sire Lexington, 
and so in my early practice I frequently found the cause in a 
remote infusion of Lexington blood, attributing to other causes, 
the more frequent appearance of the disease in draft stock, not 
related to Lexington. In the Rocky Mountain region we find 
as much of the Lexington blood comparatively as anywhere, 
the original breeding stock having been derived very largely 
