400 



General Biology 



they are often called "index fossils," as such fossils can be used to deter- 

 mine the place and period of the strata from which they are taken. 



One of the most interesting finds in 1901 was that of an ancient 

 animal, whose species is now extinct, that of a mammoth found frozen 

 in the ice of Siberia (Fig. 246), whose flesh was in excellent condition. 



In oil-bearing sands many excellent fossil specimens have also been 

 well preserved. 



But the fossil remains, which have excited most discussion and spec- 

 ulation, are those which are supposed to have belonged to human beings 

 higher in the grade of life than the highest apes we now know, and yet 



A. 



C. 



Fig. 247. 



A. Remains of Pithecanthropus erectus ; the single femur shown in different 

 aspects. 



B. Remains of the Neanderthal man in the Provincial Museum at Bonn. 



C. The Heidelberg Jaw. 



(A. From "The Open Court," B. from "Weltall V. Menschheit," C. from 

 Bryce after Schoet Ensack.) 



distinctly lower than man. Authorities, however, disagree considerably 

 as to what type of being these bones represented, some insisting their 

 possessor was human, and some that he was not. 



