442 TOWER, DARWINISM. 
as some illuminatung experiments at Tucson have shown. This 
problem we cannot consider in this paper. 
As far as my observations have gone, they are diametrically 
opposed to the cardinal principle of the Hypothesis of Natural — 
Selection. Natural Selection postulates that survival is based upon 
adaptive variations, and the results that I have obtained show 
uniformly that chance position relative to the accidents of life is 
the controlling relationship. If further examination by other observers, 
with other materials, in other locations and not in collusion with 
the Hypothesis of Natural Selection can build up an adequate body 
of knowledge concerning the processes of elimination, then it will 
be possible to decide upon the role of Natural Selection in evolution 
and upon whether it is an actuality in nature at all In conclusion 
I must point out that even the sievelike action of eliminations 
involves the simultaneous operation of very many different pro- 
cesses, each of which must be individually analyzed. as well as 
their combinations and their collective effect. These are inescapable 
relations that have existed during the course of every generation 
of all of the organisms that have ever lived and more accurate 
knowledge of them is vital to evolution studies. This paper is a 
preliminary statement of some results obtained in the effort to 
analyze that underlying problem of whether it is chance position 
relative to the accidents of life or favorable adaptive constitution 
that determines whether organisms are to survive or be eliminated. 

