loz THE POPULAR SCIENCE MONTHLY. 



appearance of the Primates. At that period, there existed lemurs in 

 Europe and America, of a transitional type, showing points of resem- 

 blance to the hoofed animals of the same age, the ancestors of our own 

 horses and tapirs. The Eocene was the epoch of the first great pla- 

 cental mammalian population, and we know that in such early epochs 

 of each main class, when the class is assuming a dominant position, it 

 always possesses an immense plasticity, rapidly dividing and subdivid- 

 ing into more and more definitely specialized types. Accordingly, it 

 was probably as early as this period that the ancestors of the higher 

 apes began to differentiate themselves from the ancestors of the mod- 

 ern lemurs. All analogy shows us that these divisions begin a long 

 way down in time, proceed rapidly at first, and grow less rapid as the 

 various creatures become more and more specialized, so losing their 

 original plasticity. 



In the Miocene, the specialization of the Primates must have con- 

 tinued very fast ; for as early as the mid-Miocene strata we find in 

 Continental Europe a large anthropoid ape, identified by good authori- 

 ties as a close relation of the modern gibbons. Other apes of the same 

 date are similarly identified as nearly allied with other living genera. 

 Hence the question naturally arises if the bifurcation of the Primates 

 had already proceeded so far in the mid-Miocene period that even ex- 

 isting genera of higher apes had been fairly well demarkated, must not 

 the ancestors of man have already begun to be generically distinct 

 from the ancestors of the other anthropoids ? Is it not consonant with 

 analogy to suppose that the monkey group should have separated from 

 the lemur group in the Eocene ; that the anthrojtoid apes should have 

 separated from the monkeys in the lower Miocene ; and that the hu- 

 man genus (as distinct from the fully developed human species) should 

 have separated from the anthropoid apes in the mid-Miocene ? There 

 seems to be good reason for this conclusion. 



In mid-Miocene strata at Thenay, the Abbe Bourgeois has found 

 certain split flints, some of them bearing traces of fire, which he 

 believes to be of artificial origin ; and in this belief he is upheld by 

 M. de Mortillet, Dr. Hamy, MM. de Quatrefages, Worsaae, and Capel- 

 lini, and other distinguished anthropologists. Specimens may be seen 

 in the Musee de St. Germain, almost as obviously human in their work- 

 manship as any of the St. Acheul type. M. Delaunay has similarly 

 found a rib of an extinct manatee, which seems to have been notched 

 or cut with a sharp instrument ; and M. Ribeiro, of the Portuguese 

 geological survey, has noted wrought flints in the Miocene deposits of 

 the Tagus, which he exhibited in Paris in 1879. On the evidence of 

 these and other facts M. de Mortillet pronounces in favor of what he 

 calls Tertiary man. But as he carefully distinguishes him from Qua- 

 ternary man, "l'homme de St. Acheul" the river-drift man of Pro- 

 fessor Dawkins I suppose he means to imply that this species, though 

 belonging to the same genus as ourselves, was yet so far unlike us, so 



