DOES ACQUIRED VIGOR COUNT? 267 
vigor of the germ-cells, and the developmental 
vigor of particular items in the inheritance. The 
evidence brought forward in support of this view 
is confessedly indirect. In his experience as a 
breeder Mr. Bonhote has been puzzled by many of 
his results. He could not interpret them in terms 
of Mendelian, Galtonian, or any other formule, but 
he found them intelligible on the theory that the 
physiological condition of the parents at the time 
of reproduction may influence the germ-cells and 
their development. Low vigor in the parents will 
tend to be echoed in weakly offspring; high vigor 
will make for racial stability. But what is required 
is careful and skeptical criticism of all the evidence 
that points to the conclusion that the constitutional 
vigor, or vitality, or healthfulness of the parents at 
the time of parentage really counts in the devel- 
opment of the offspring. This is a momentous 
question, not to be answered by opinions, or on 
hearsay evidence, or even by reference to particular 
observations, such as the often-noticed delicacy of 
the children of a more or less invalided and worn- 
out father. In the case of Mammals the problem is 
complicated by the usually prolonged period of 
intimate symbiosis between the mother and the 
offspring, during which it would be strange indeed 
if the development were not sometimes perturbed 
when there are profound changes in the maternal 
metabolism. That such perturbations are not more 
noticeable is largely due to subtle adaptations which 
screen the young life from harm. 
