330 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
During the past year great advances have been made in the long- 
neglected field of aerobiology, dealing with the distribution of pollens, 
fungus spores, micro-organisms, etc., through the air; new knowledge 
of the spread of contagion through the air has been obtained, and 
new methods of control worked out, using vapors and ultraviolet rays. 
Also within the year there have been a number of new biological 
methods of controlling pathogenic organisms, including discovery 
of an enzyme-like substance in young rats, by which tuberculosis ba- 
cilli may be shorn of the waxy coats that protect them from drugs 
and phagocytes, and discovery of germ-killing substances extracted 
from molds and from various types of soil bacteria. In the field of 
nutrition, evidence for the need of particular amino acids for special 
functions in the body have been demonstrated, and may pave the 
way for better control of these functions in the future. New methods 
have been developed for the study of the ultimate connections be- 
tween nerves and muscles, which may lead to better control of paralysis 
and muscular diseases. Announcement has also been made of the de- 
velopment of germ syrups, at negligible cost, which change the bac- 
terial life of the human intestine so that, like deer and cattle, we can 
not only digest the cellulose of grass, leaves, and wood, but can also 
synthesize our own supply of B vitamins within our own bodies. In 
research on cancer, which is one biological problem that is still un- 
solved, a number of significant advances have been made. A few 
more pieces have been fitted into the mosaic, bringing the final pic- 
ture a little nearer to completion. In this field as in that of allergies, 
there is still much to be done, but there is every reason to believe that 
it will be done before very long. 
Man’s ingenuity has freed him from many phases of the struggle 
for existence to which other creatures are subject. He has gained 
an insuperable advantage over the wild beasts, and his inventive genius 
defies the attacks of climate and the elements. In his struggle against 
disease he has, as we have seen, made wonderful progress, although 
he still has far to go. There is some reason to hope that after the 
present global war has burned itself out we may be able to free our- 
selves from the one phase of the struggle for existence that man’s 
ingenuity has steadily made more terrible, the struggle of man against 
man. With all the phases of the struggle for existence well in hand 
we may then turn to a struggle for improvement of our kind by the 
application of two other branches of biological science, genetics and 
eugenics. Within our own generation preventive medicine has 
grown out of therapeutic medicine; perhaps our children may live 
to see a still newer branch of “improvement medicine,” in which en- 
docrinology, nutritional studies, problems of aging and rejuvenescence, 
and eugenics will lead to greater health, more happiness, longer life, 
and better evolutionary prospects than have hitherto been our lot. 
