34° BIOLOGY AND ITS MAKERS 
Paleontology, by treating fossil life and recent life in the 
same category, has come to be one of the important lines of 
investigation in biology. It is, of course, especially rich in 
giving us a knowledge of the hard parts of animals, but by 
ingenious methods we can arrive at an idea of some of the 
soft parts that have completely disappeared. Molds of the 
interior of the cranium can be made, and thus one may form 
a notion of the relative size and development of the brain 
in different vertebrated animals. This method of making 
molds and studying them has shown that one characteristic 
of the geological time of the tertiary period was a marked 
development in regard to the brain size of the different 
animals. ‘There was apparently, just prior to the quaternary 
epoch, a need on the part of animals to have an increased 
brain-growth; and one can not doubt that this feature which 
is demonstrated by fossil life had a great influence in the 
development of higher animal forms. 
The methods of collecting fossils in the field have been 
-greatly developed. By means of spreading mucilage and 
tissue paper over delicate bones that crumble on exposure 
to the air, and of wrapping fossils in plaster casts for trans- 
portation, it has been made possible to uncover and preserve 
many structures which with a rougher method of handling 
would have been lost to science. 
Fossil Man.—One extremely interesting section of pale- 
ontology deals with the fossil remains of the supposed 
ancestors of the present human race. Geological evidence 
establishes the great antiquity of man, but up to the present 
time little systematic exploration has been carried on with 
a view to discover all possible traces of fossil man. From 
time to time since 1840 there have been discovered in caverns 
and river-gravels bones which, taken together, constitute an 
interesting series. The parts of the skull are of especial 
importance in this kind of study, and there now exists in 
