306 BIOLOGY AND ITS MAKERS 
added another by the discovery in 1906 of a supposed prim- 
itive race of men in Nebraska. The two skulls unearthed 
in Douglass County in that State indicate a cranial capacity 
falling below that of the ‘‘ Australian negro, the lowest existing 
type of mankind known at present.” 
Fig. 111 shows in outline profile reconstructions of the 
skulls of some of the fossil types as compared with the short- 
headed type of Europe. 
Paleontological discoveries are thus coming to support 
the evidences of man’s evolution derived from embryology 
and archeology. While we must admit that the geological 
evidences are at present fragmentary, there is, nevertheless, 
reasonable ground for the expectation that they will be 
extended by more systematic explorations of caverns and 
deposits of the quarternary and late tertiary periods. 
Mental Evolution:—Already the horizon is being wid- 
ened, and new problems in humanevolution have been opened. 
The evidences in reference to the evolution of the human 
body are so compelling as to be already generally accepted, 
and we have now the question of evolution of mentality to 
deal with. The progressive intelligence of animals is shown 
to depend upon the structure of the brain and the nervous 
system, and there exists such a finely graded series in this 
respect that there is strong evidence of the derivation of hu- 
man faculties from brute faculties. 
Sweep of the Doctrine of Evolution.—The great sweep 
of the doctrine of evolution makes it ‘one of the greatest 
acquisitions of human knowledge.” There has been no 
point of intellectual vantage reached which is more inspiring. 
It is so comprehensive that it enters into all realms of thought. 
Weismann expresses the opinion that ‘“‘the theory of descent 
is the most progressive step that has been taken in the devel- 
opment of human knowledge,” and says that this position 
“is justified, it seems to me, even by this fact alone: that the 
FSSESSS) 
