ON THE QUICK GROWING WALNUT 
there is an underlying assumption to the effect 
that the various modifications of the individual 
are transmitted to the offspring of the individual. 
Unless such is the case, it is clear that there 
could be no such thing as the evolution of new 
species. It would avail nothing for the progeny 
of an individual that this individual was well 
adapted to its surroundings, unless the said 
progeny inherit the characteristics that made such 
adaptation possible. 
There is no logical escape from that conclusion. 
Whatever our conception of the mechanism of 
heredity, or of the exact manner in which the 
transmission of variation occurs, no one can be an 
evolutionist who does not believe that acquired 
characters are transmitted through heredity. 
There was a school of biologists who gained 
great prominence a few years ago, who denied the 
possibility of the transmission of acquired traits. 
Throwing logic to the winds, they based their 
denials on a metaphysical interpretation of certain 
observed microscopic structures within the germ- 
cell. These same biologists, while denying that 
acquired traits could be transmitted, were at the 
same time ardent upholders of what they called 
Darwinian evolution. 
But such a paradoxical contention must of 
necessity fail to maintain itself for any consider- 
[213] 
