EVIDENCE FOR EVOLUTION FOUND IN EXTINCT MAMMALIA. 301 
simian. Our greatest ignorance lies in the direction of the structure of higher 
extinct apes, whose teeth have been found, but of whose skulls we know nothing. 
But it is really of less than usual importance that such a form should be discovered 
'{though I have no doubt it will be ; for we have so often bridged wider gaps than 
that between homo and simia that the evidence may be regarded as sufficient. 
All that'is necessary is to change the direction of the tendon which supports the 
first toe of the posterior foot, so that it shall become straight and not divergent 
from the other toes : to reduce a little the size of the canine teeth, and the space 
in front of the inferior canine, and the change from genus to genus is complete. 
The approximations already known render it probable that the change has already 
occurred. 
The speaker here illustrated by a table upon the blackboard the characters 
which distinguish certain families of geological mammalia, together with the char- 
acter and period of their changes. The changes were seen first in the limbs and 
feet, second in the teeth, third in the hair. The formations mentioned were all 
tertiary. The table- showed that during this period the hoofed mammalia under- 
went general modifications of structure in many ways. The toes became less 
numerous and the feet larger; the ankle and wrist joints became more perfect; 
the teeth passed through a great number of stages from simple to complex, and 
the brain increased greatly in size and complexity. An examination of these 
changes, said the speaker, demonstrated that they were all of the nature of 
mechanical improvements for the accomplishment of work. Many evolutionists 
are content to leave the question at this point — the survival of the fittest. But 
this is not enough. 
The Darwinians proper, he continued, have been willing to treat the varia- 
tion of form, as a matter of course, and as taking place in all directions and ways. 
They have openly or tacitly avowed a doctrine of omnifarious variation. This 
mode of stating the case has met with adverse criticism within and without the 
ranks of the evolutionists. It is contrary to the so-called law of chances that 
such omnifarious variation should produce the exact adaptations so wonderfully 
•displayed on every hand ; and paloeontology distinctly negatives any such suppos- 
tion. Evolution had proceeded along lines of profitable variation ; it is even 
probable that most variations have been profitable in some direction, and that 
the extinction of so many of the hnes has been due to the fact that they have not 
•been permanently, but only temporarily beneficial. In a word, "the origin of 
the fittest" has been adaptive in its direction, and for this there is only one ex- 
planation — i. e.y the action of mind. And it is altogether probable that this mind 
is to be found in the animal itself, and has acted as the director gf its movements. 
If the movements have produced the structures under the influence of impacts, 
strains, etc., as I believe to be the case, and expect to see proved, the relation 
of mind to the development of types becomes clear, and explains the origin of 
ithe fittest 
