erican naturalists, whose best representative is
Dr. E.D. Cope of Philadelphia.[202] This school endeavours to explain
all the chief modifications of form in the animal kingdom by fundamental
laws of growth and the inherited effects of use and effort, returning,
in fact, to the teachings of Lamarck as being at least equally important
with those of Darwin.

The following extract will serve to show the high position claimed by
this school as original discoverers, and as having made important
additions to the theory of evolution:

"Wallace and Darwin have propounded as the cause of modification in
descent their law of natural selection. This law has been epitomised by
Spencer as the 'survival of the fittest.' This neat expression no doubt
covers the case, but it leaves the origin of the fittest entirely
untouched. Darwin assumes a 'tendency to variation' in nature, and it is
plainly necessary to do this, in order that materials for the exercise
of a selection should exist. Darwin and Wallace's law is then only
restrictive, directive, conservative, or destructive of something
already created. I propose, then, to seek for the originative laws by
which these subjects are furnished; in other words, for the causes of
the origin of the fittest."[203]

Mr. Cope lays great stress on the existence of a special developmental
force termed "bathmism" or growth-force, which acts by means of
retardation and acceleration "without any reference to fitness at all;"
that "instead of being controlled by fitness it is the controller of
fitness." He argues that "all the characteristics of generalised groups
from genera up (excepting, perhaps, families) have been evolved under
the law of acceleration and retardation," combined with some
intervention of natural selection; and that specific characters, or
species, have been evolved by natural selection with some assistance
from the higher law. He, therefore, makes species and genera two
absolutely distinct things, the latter not developed out of the former;
generic characters and specific characters are, in his opinion,
fundamentally different, and have had different origins, and whole
groups of species have been simultaneously modified, so as to belong to
another genus; whence he thinks it "highly probable that the same
specific form has existed through a succession of genera, and perhaps in
different epochs of geologic time."

Useful characters, he concludes, have been produced by the speci