298 SECRETS OF ANIMAL LIFE 
appearance; there is a clear hereditary factor in 
licentiousness; pauperism indicates bodily or 
mental weakness, and the latter is linked with 
criminality; penal institutions have little beneficial 
influence upon persons of defective mentality; 
one in four Jukes is improved socially by Children’s 
Institutions; a change of environment gives the 
individual a new opportunity and a chance of 
mating into better families. In many cases, how- 
ever, the ne’er-do-well in new surroundings finds 
another like himself. Improved social environment 
demonstrably counts for much in the individual's 
development, but this depends on the response 
that he is able and willing to make, and the power 
of response depends on the hereditary constitution. 
Yet “ heredity, whether good or bad, has its comple- 
mental factor in environment.” 
Mr. Dugdale laid emphasis, as we have said, on 
the deteriorative effect of continuous bad surround- 
ings; Dr. Estabrook’s study, carefully documented 
with genealogical trees, shows that the hereditary 
factor is in some cases equally important, e.g., as 
regards weak-mindedness. It is probably unjust to 
trace all the innate deficiencies of later date to the 
original Juke strain, since evils bred in the bone 
would be sometimes accentuated by mating with 
similarly disposed members of other stocks. As to 
weaknesses that can be classed as Mendelian unit- 
characters—a question very partially answered, 
it must be noted that outbreeding with normal 
members of the community would affect the dis- 
