342 BIOLOGY AND ITS MAKERS 



Palaeontology, 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 palae- 

 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 



