
TOWER, DARWINISM. 419 
The difficulty with the Hypothesis of Natural Selection is that 
there is very slight evidence of any kind that the principles of 
Operation formulated by DARWIN are actually working in nature. 
Instances of elimination such, for example, as WELDON’s crabs in 
Plymouth Harbor, Bumpus’ English sparrows in New York and a 
few other like instances have been held to show elimination taking 
place along lines similar to those which DARWIN conceived as 
Operating in nature. Rare instances of this sort hardly provide 
adequate proof that Natural Selection was changing the species 
observed. 
The entire problem of Natural Selection centers around the cha- 
racter of the individuals that are eliminated as well as around the 
reason why they failed to survive; and until much more is known 
concerning this aspect of the fundamental fact that underlies Na- 
tural Selection, Darwın’s Hypothesis will continue to be a plau- 
sible explanatory hypothesis; but without definite proof. It is not 
easy to determine, there are, in fact, perhaps no criteria available 
at present whereby it is possible to decide categorically whether 
the individuals eliminated are unfit and unadapted. Consequently 
for the present the problem must receive elucidation from obser- 
vation and experiment by indirect attack. 
I have sought evidence in support of the principle of Natural 
Selection that was not based upon assumption and plausible ex- 
planation. 
These observations and experiments have centered around the 
question of... whether those individuals which persisted and 
reached maturity are those which possess variations of a nature 
such that they are thereby more efficient than their fellows and 
hence are better able to compete successfully in the struggle for 
existence. or whether the survivors are those individuals whose 
chance position, when the accidents of life happen, saves them 
from extinction and eliminates their less fortunately placed com- 
panions. This is the crux of the whole situation concerning Na- 
tural Selection; that is, whether it is fortuitous variation or acci- 
dental position which determines survival. It is this aspect of the 
Natural Selection problem that is considered in this paper. Upon 
