EXPERIMENTAL STUDY OF HEREDITY 567 
ignorance, and crime; and how to increase the number 
of individuals physically, mentally, and morally more 
robust and sound; and withal how, if possible, to raise 
the standard of all desirable human traits. A careful 
study of heredity and eugenics will make possible a much 
more intelligent and efficient program for charity work 
and social betterment. 
488. Investigations Since Mendel. It must be re- 
membered that Mendel's most valued contribution was 
not the observations which he made and recorded con- 
cerning the garden pea, nor the hypotheses which he ad- 
vanced on the basis of those observations, but this method 
of procedure, whereby he elevated the study of heredity 
to the rank of an exact science. As in the case of all 
hypotheses, the task for science is to subject them to the 
most searching tests, to see if they invariably agree with 
facts, and may be accepted as in all probability embody- 
ing the actual truth may be elevated to the rank of 
theories. The testing of Mendelism has been occupying 
all the best talents of many investigators since the re- 
discovery of Mendel's publication, about 1900. Many 
biologists are still skeptical, others reject the hypotheses, 
and still others believe they contain the germ of truth, 
but must be more or less modified. Whether they prove 
to be erroneous or true is not so important, but it is impor- 
tant for us to know which is the case. True or not, 
they, like nearly all working hypotheses (natural selec- 
tion, mutation, nebular hypothesis, atomic hypothesis 
in chemistry, etc.) are rendering, or have rendered, a 
priceless service to science by pointing the way to further 
study, which enriches our knowledge of the living world, 
including ourselves, and therefore increases the intelli- 
