TRANSMISSION OF MODIFICATIONS 405 



degeneracy beyond under-development in individuals, or as 

 associated with cessation of selection are in any way the result 

 of disuse ; whether an individual is a better parent after a long 

 course in exercise or training, or a worse one after a long life 

 of idleness, than the same individual would have been before ; 

 whether a race horse will transmit better speed after he or she 

 has been " developed," and has made a record on the track, than 

 he or she would have transmitted if never tracked ; whether the 

 later children of a studious or of an athletic man (or woman) 

 will be born with more ability in these directions than the earlier 

 ones, and whether the younger children of criminals are more 

 inclined to criminality than are those born before the criminal 

 instincts were fully developed in the parents. The real question 

 is this : Is transmission augmented or lessened by the degree of 

 development to ivldcJi racial characters have attained in the indi- 

 vidual before parentage, and without reference to selection ? 



In the opinion of the writer there is not yet sufficient evi- 

 dence on which to base a final decision, and much as we all 

 desire a settlement of the matter, and much as we need to 

 know what the real truth is, nothing is gained by passing pre- 

 mature judgment, and the question must be left for the time 

 unanswered. 



For the present the student must content himself with learn- 

 ing to know the field of discussion, and, inasmuch as he must 

 hold his opinions in abeyance, it is important that he know the 

 arguments pro and con. If he do this, and keep his ear to the 

 ground, he will find the question clearing up rapidly in the near 

 future ; we may be nearer its solution than the most careful 

 biologists have yet dared to hope. 



Not going back of the fact that no somatic variation can pos- 

 sibly become blastogenic, Weismann and his followers deny in 

 toto all possibility of such transmission, although Weismann him- 

 self has admitted, as a result of his own experiments with the 

 colors of butterflies as dependent upon temperature, that such 

 all-pervading conditions as heat may penetrate to the germ and 

 affect its character as well as that of the tissues of the body. 

 In the opinion of many recent writers the list of " all-pervading" 

 influences includes much more than temperature alone. 



