

TOWER, DARWINISM. 431 
three stations in the barrancas and left to their fate. When this 
Station was seen in the following year, a Strong population of 
beetles was present, showing that the dry conditions were not 
prohibitive to the species after the egg stage had been passed. 
They had completed their transformation, aestivated successfully, 
emerged and were laying eggs, but these eggs had dried up precisely 
as in the other dry locations. The egg Stage is apparently the 
crucial period in the life cycle of this beetle and largely determines 
its permanent habitudinal positions and adjustments. The point of 
interest for this paper is that neither in nature nor in experiment 
were any differences discovered to indicate that the eggs of this 
species, taken at random from. wild examples and from stocks in 
captivity, had any properties upon which a differential survival 
capacity could be based. Both in nature and in experiment, elimination 
through desiccation was clearly due to fortuitous position rather 
than to different adaptive capacities. An instance of this kind is 
one that, conceivably at least, ought to yield differential survival 
results, if survival depends on the existence of best-fitted individuals, 
but no evidence of this was ever obtained. 7 
The general result that comes from an examination of the problem 
of survival and elimination statistically investigated, in different 
locations and followed in many places through a period of years, 
has shown that elimination in nature in the instances examined is 
entirely due to the chance position that the eliminated happened 
to occupy relative to the accidents that constantly menace their 
existence and did not depend in any discovered respect upon 
adaptive capacities or variations. Elimination, as far as observed in 
these instances, would be non-efficient, non-directive and non- 
cperative in any evolutionary process that is known. I am not 
asserting that natural eliminations may not have this directive effect, 
but only stating that as far as discovered in the instances examined, 
the effectiveness of elimination to produce changes and modifica- 
tions of the organisms observed would be zero. 
BY EXPERIMENTAL TEST. 
The object of these experiments was to discover what was 
involved in elimination, that is, whether elimination was due to 
