THE EVOLUTION OF MAN 



hypothetical mixed group have not yet been lo- 

 cated. But it must be remembered that our dis- 

 cussion is now dealing with sections of the 

 earth's history which are extending into eons of 

 time in which all things are becoming indistinct 

 and vague. To the extent that we venture into 

 the dim past, our proofs must be founded more 

 and more on circumstantial evidence. No one 

 could expect that all the typical stages and their 

 inter-relations should be distinctly seen, it must 

 be sufficient to trace in its approximate outlines 

 the logical course of the main growth. There 

 are a great number of special witnesses to make 

 a good case for our further investigation. 



We have now gotten far beyond the saurian 

 period into the so-called Primary age. We are 

 approaching those most ancient epochs which 

 gives us any direct evidence of primitive life on 

 earth by means of petrified specimens. We meet 

 in that period numerous masses of mineral 

 strata, which were once precipitated to the bot- 

 tom of the sea in the form of mud. These strata 

 bear no other fossil remains of animals than 

 those of fishes. Evidently these were then the 

 sole representatives of the animal world. 



We receive the impression that all animal life! 

 I at that remote Primary age was concentrated in | 



94 



