228 University of California Publications in Zoology \Vou.9 
as civilization advances, it must become ever more and more an 
underpinning and ally of all these. 
The distinction between an institution of applied science and 
one of pure science might be stated thus: The former is one the 
primary aim of which is to use certain more or less well-estab- 
lished truths and principles of science to the answering of 
man’s needs and desires in certain well-defined directions. For 
example, the Bureau of soils of the United States Department of 
Agriculture is for the purpose of applying chemistry, physics, 
and geology to the end of increasing the productivity of the land 
of the United States. The Liverpool School of Tropical Medicine 
is for the ‘‘perfeetion of physicians in tropical hygiene’’ and 
for ‘‘investigations in tropical diseases.’’ An institution of pure 
science, on the other hand, should be one the primary aim of 
which is to extend the bounds of man’s knowledge of nature in 
a specified field, and to show something of the significance of the 
new knowledge for the higher life of mankind. To be more 
definite, an institution of research in biology or in astronomy 
could justify its existence, in a democratic country like ours, 
only by making considerable additions to knowledge and then by 
showing, in language comprehensible to the generally but non- 
technically educated members of the community, something of the 
meaning of this knowledge for human beings in both the physical 
and the spiritual aspects of their natures.* 
I now mention certain biological discoveries and generaliza- 
tions which have, as I believe, very great importance to civilized 
men but which are by no means as widely known as they ought 
to be and might be, and which can become thus known only 
through the efforts of professional biologists. 
The significance of omne vivum ex vivo (all life from preced- 
ing life) not only for philosophic biology but for the attitude of 
thoughtful people generally toward the problems of practical 
+The soundness of this view is dependent upon the soundness of two 
assumptions which cannot be argued here but which may be briefly stated: 
1. The person of average natural endowment and education in the United 
States is capable of understanding the most essential things in any scientific 
discovery that has ever beefi made or is likely to be made for many years 
to come. 2. It does ‘‘matter’’ enormously not only to the individuals but 
to the nation as a whole, whether or not those who are capable of this much 
understanding have an opportunity to get it. 
