ioo THE MAIN CURRENTS OF ZOOLOGY 



culture periods, which are well exhibited in different 

 parts of France and Central Europe. No less than 

 six culture-periods of palaeolithic man are known, 

 indicating that the prehistoric period of human 

 development was far longer than the entire historic 

 period. 



It is, however, to fossil remains of primitive man 

 that we must look for evidences of structural changes 

 that have taken place in the human frame. 



Of all the bony parts, the skull is the most interest- 

 ing for comparison, since its size and configuration 

 indicate in a general way the degree of development 

 of the brain, and, as a consequence, the relative 

 grade of intelligence. 



One of the most famous documents of man's an- 

 cestral history is the well-known Neanderthal skull, 

 discovered in a cave near Diisseldorf in the valley of 

 the Neander, in 1856 and first described in 1857. It 

 is now exhibited with other parts of the skeleton in 

 the provincial museum at Bonn on the Rhine. The 

 inferences drawn from this very ancient skull, with 

 its low receding forehead, showing small develop- 

 ment in the region of the higher mental faculties, 

 created a sensation, and great opposition was devel- 

 oped in allowing the discovery to rank as an evidence 



