300 SECRETS OF ANIMAL LIFE 
“Out of approximately 600 living feeble-minded 
and epileptic Jukes, there are now only three in 
custodial care. It is estimated that at the end of 
fifty years the defective germ-plasm would be 
practically eliminated by the segregation of all of the 
600.” (3) A third proposal, to be considered very 
critically, is to improve bad stock by letting it 
mingle with good. If we were able, as we are not, 
to distinguish beforehand between characters that 
blend and characters that Mendelise, it might be 
practicable to get a passable average man from a 
good mother and a bad father, but in reference to 
well-defined characters the trend of investigation 
is strongly against any such experimenting. It is 
probable that the very worst thing a man can do is 
to taint good stock with bad. The children of such 
unions may turn out not badly, if they are brought 
up in conditions of wholesome nurture, and the taint 
(if a unit-character) may be wholly absent in some 
members of subsequent generations, but without 
the aid of persistent selection it cannot disappear 
from the lineage. When children genetically sound, 
but by individual malnutrition weakly, are trans- 
planted to good environment, they often do well; 
and if they grow up, settle down and marry, no 
stock is harmed. But Dr. Davenport justly doubts 
the wisdom of sending “much bad germ-plasm to 
good farming communities throughout our Middle 
West.” Dr. Davenport has done valuable service 
to the science of genetics, but we wish he had not 
written a sentence like this: “It is probable that, 
