UTAH ACADEMY OF SCIENCES 73 
To the hook-worm alone he attributed the “laziness” and 
general shiftlessness of the poor whites in the sand-lands 
and pine-barrens of the South. It is said that physicians 
laughed at his “theory”, as they called it; but finally be- 
came convinced of its truth. And when we consider that 
fifty cents worth of medicine will cure a man who has been 
a life-long sufferer from this terrible affliction, and that by 
proper sanitary measures it can be absolutely prevented; 
when we consider that Dr. Stiles’ discovery will regenerate 
certain portions of the South, and give health and hap- 
piness to one-fiftieth of the population of the United States, 
we surely must conclude that biological science has added 
its share to the peace and prosperity of the world, notwith- 
standing the fact that many of our friends on the outside 
would look on with a good natured smile at the work of 
collecting, classifying and studying the various kinds of 
worms found in the intestines of dogs, sheep, badgers, foxes, 
etc. 
Another prolific line of recent investigation has been 
that of insects as carriers of disease. The discoveries of 
the last few years in regard to the connection between the 
mosquito and malarial fever, yellow fever, and certain tropi- 
cal fevers are still fresh in the mind. As to the practical 
results of these studies we have but to turn to Havana, a 
hot-bed of yellow fever for over two centuries, but now 
free from the disease; or we have but to compare the over- 
whelming death-loss at the Panama canal during the De 
Lesseps regime with the extremely low mortality existing 
there now. 
And so, as the biologist discovers the life history of 
these various animal and plant parasites, the physician ex- 
tends applied knowledge along his own special lines; 
until we may hope that in the not far distant future, a 
certain class of diseases will become extinct. Among these 
diseases, none gives more promise of early extinction than 
typhoid fever. In the year 1890, 2.2 per cent of all deaths 
in the registration area of the United States had been 
caused by this disease. In 1900, this had been reduced to 
1.9 per cent, and in 1910 to 1.6 per cent. 
