HISTORICAL ACCOUNT OF EVOLUTION THEORY 35 
three-factors: a standstill or cessation of development on the part of 
some lines; sudden development by leaps (practically mutations); 
and hindrance or difficulty of reproduction (the type of thing that 
Romanes emphasized as physiological isolation ten years later). 
Eimer illustrated his theories by the evolution of color patterns in 
lizards and those on the wings of butterflies. In both he believed that 
longitudinal stripes were primitive, that rows of dots followed these 
which were in turn followed by crossbands, reticular patterns, and 
finally by solid coloration. This hypothetical phylogenetic order is 
more or less closely paralleled by the ontogenetic order, in the 
lizards at least. 
It will be noted that Eimer’s theory places natural selection in a 
subordinate position, but does not dismiss it altogether, as is done by 
Nageli. It aids natural selection in explaining adaptations in that it 
furnishes for natural selection various characters of selective value, 
which may be either perpetuated or eliminated according to their 
utility. 
E. D. Cope, a leading American palaeontologist of the past cen- 
tury, had an orthogenetic theory involving his ideas of “‘bathmism” 
(growth force), “kinetogenesis” (direct effect of use and disuse and 
environmental influence), and “‘archaesthetism” (influence of primi- 
tive consciousness). It may be said that his ideas were Lamarckian 
throughout. In common with the majority of palaeontologists of 
later date—Osborn, Williston, Hyatt, Smith, and others—Cope felt 
the need of some factor other than natural selection to explain the 
apparent steady progress of characters in definitely directed lines as 
seen in the fossils. It is natural therefore that palaeontologists almost 
universally lay hold of both Lamarckian and orthogenesis ideas. 
Charles Otis Whitman, who, until his death over ten years ago, was 
considered the leading American zodlogist, had strong leanings toward 
orthogenesis. In one of his few publications he says: 
“Natural selection, orthogenesis, and mutation appear to present 
fundamental contradictions; but I believe that each stands for truth, 
and reconciliation is not far distant. The so-called mutations of 
Oenothera are indubitable facts; but two leading questions remain to 
be answered. First, are these mutations now appearing, as is agreed, 
independently of variation, nevertheless the products of variations that 
took place at an earlier period in the history of these plants? Secondly, 
if species can spring into existence at a single leap, without the assist- 
ance of cumulative variations, may they not also originate with such 
