primary and secondary industries, and to both 
benefit and threaten the welfare of plants, 
animals, and man. The same boundlessness 
characterizes the problem at the other ex- 
treme, the cellular and molecular level. Here 
chemists and physiologists work to relate 
chemical structure and toxicity and to eluci- 
date modes of action while geneticists probe 
the phenomenon of resistance. Between these 
extremes is a vast middle ground where 
engineers, physicists, and meteorologists 
strive to get better pesticide coverage; ento- 
mologists, plant pathologists, agronomists, 
and economists struggle to determine when 
pesticide use is justified; and ecologists and 
mathematicians attempt to develop sampling 
and analytical techniques appropriate to the 
populations being studied. Much the same 
order of diversity characterizes the field of 
biological and other methods of control and, 
of course, the use of combined or integrated 
control measures, which is bound to receive 
more and more attention in the future. It is 
easy to see why we have come to recognize 
such hybrid specialties as biochemistry, bio- 
physics, biometeorology, biomathematics, and, 
finally, biogeochemistry. These significant de- 
velopments provide further testimony that 
training in restricted disciplines is insufficient 
to meet the research problems of today. Highly 
trained specialists are indispensable in modern 
research; but for applied research in depth, 
teams of such specialists are commonly needed. 
EXPERIENCE FROM CHEMICAL 
CONTROL 
The use of pesticides illustrates some of the 
complexities inherent in the development and 
administration of pest-control programs. We 
should profit from this experience in looking 
ahead, especially since there is every likeli- 
hood that the use of pesticides will be con- 
tinued indefinitely into the future. 
In the last two decades, the use of pesti- 
cides has provided billions of dollars' worth of 
food and fiber and prevented countless human 
illnesses. But the lavish use of such a variety 
of toxic substances in so many different formu- 
lations and under so many different environ- 
mental conditions has raised a question that 
cannot be fully answered: What is the long- 
term hazard to man's productive environments 
and to man himself of continuing this practice? 
Public interest has been widely aroused. 
Agriculturists, foresters, and health authori- 
ties are well aware of the advantages achieved. 
They remain the principal users and, in 
general, the main supporters for continuation 
of pesticide use, albeit with increased precau- 
tions for safety. Those responsible for the pro- 
duction of fish and wildlife and for other con- 
servation programs are more fearful of the 
consequences and less anxious to see chemical 
control continued on the current scale. The 
chemical industries are directly involved, of 
course, and the lay public has expressed itself 
variously and vigorously. 
Governments have introduced statutory safe- 
guards at both the regional and federal levels 
in most advanced countries to require regis- 
tration of pesticides before sale, to limit 
specific uses of certain compounds, and to 
regulate the amount of pesticide permitted in 
food entering commercial markets. The ques- 
tion of food contamination extends into inter- 
national trade and carries with it, among 
others, a need for international agreement on 
methods for measuring pesticide residues. 
Such analytical techniques have advanced spec- 
tacularly in recent years. Now we can detect 
the presence of many compounds in parts per 
billion or even per trillion. This refinement 
means that products may now be declared 
"contaminated,'' which previously, by less 
sensitive methods, would have been certified 
free of residues. This change greatly compli- 
cates the administration of official residue 
tolerances, especially where regulations per- 
mit no contamination. The confusion arises 
from the fact that in many instances our ability 
to detect the presence of a pesticide has out- 
stripped our capacity to interpret the signifi- 
cance of the amount found. 
With few exceptions, it is impracticable to 
experiment directly on humans. Consequently, 
both acute and chronic toxicity of a compound 
to man have to be gaged from studies with ex- 
perimental animals. This approach has ac- 
knowledged weaknesses. Nevertheless, the 
record so far has been remarkably good. I am 
not aware of any human poisonings as a result 
of the marketing of food contaminated with 
pesticides. The Food and Drug Regulations 
appear to be providing adequate safeguards in 
this regard. But in addition to problems in 
