18 
THIRTEENTH REPORT. 
RECENT ACHIEVEMENTS IN PARASITOLOGY 
FREDERICK G. NOVY. 
It is well known that science in its varied branches has made wonder- 
ful strides during the past few decades. New modes of thought or points 
of view as well as new methods of attack have had much to do with the 
success achieved. Departments of science undreamed of before have 
thus come into existence and have attained rapid growth. As in the 
case of a new and. fertile country where the pioneers’ path is soon 
traversed bv many settlers, so in this or that new science we find that 
e 
its few explorers before long have many followers who devote them- 
selves industriously to developmental work. At no time in the past has 
there been such a large number of workers engaged in science as at 
the present day, and it is because of this large number of devotees that 
so much, quantitatively at least, is accomplished. Rapid exploitation 
of a promising field is a rule in the crowded business life and is none 
the less observed in science. It is the inevitable result of the conditions 
which obtain today, namely an ever-increasing number of trained men, 
rapid means of communication, and an abundant opportunity for publi- 
cation. The path of progress, however, need not be and indeed is not 
always straight for the reason that problem, method and observer are 
subject each to its peculiar variation or inaccuracy. Yet after all, 
errors such as they are soon become corrected and some real advance is 
made. 
The achievements for the decade just closed make a most interesting 
chapter in the history of science and augur well for the new century. 
To attempt a general survey of a decade’s scientific work would be to 
say the least inadvisable and it is not my intention to undertake such 
a task. I have thought, however, that it would not be out of place to 
present a brief account of some of the more notable results in fields of 
work with which I have some acquaintance. 
The control and eradication of disease has been a fruitful topic for 
research ever since Pasteur paved the way, first by his remarkable 
studies on the silkworm disease, then by his* classical studies on at- 
tenuation, especially that of the virus of anthrax and rabies. In the 
case of the silk-worm disease which threatened to impoverish France, 
Pasteur practically put an end to the malady by developing means for 
its detection and prevention. The corpuscles of Cornalia which we 
today recognize as the spores of a protozoon ( Nosema bombycis) were 
not considered by him as the cause but rather as reaction products com- 
parable to tubercles and cancer cells. Nevertheless he realized their 
diagnostic importance and by finding these bodies in the dust and 
sweepings of rooms where the worms were raised he was led to believe 
that the worms became infected by feeding upon the leaves laden with 
the infected dust. A series of tests confirmed the belief and gave, what 
we realize today, the first experimental transmission of a protozoal 
