174 THE TRANSFORMATIONS OF THE ANIMAL WORLD 



that of Cernay-les-Rheims in France, are the first 

 faunas where, side by side with Multituberculata 

 and polyprodont Marsupials, we note the presence 

 of undoubted placental Mammals. But it should 

 be remarked that already, from the ancient epochs 

 of the lower Eocene, the Placentals are differentiated 

 into distinct groups, in which it is easy to recognize 

 the representatives of several orders, some extinct, 

 like the Condylarthra, the Arriblypods, the Tillo- 

 donts, and the carnivorous Creodonts ; the others, 

 the Insectivora and the Primates, continuing with 

 light modifications to our own time. Perhaps, 

 as has frequently been said, the differential charac- 

 ters of the orders are not, in these early faunas, 

 as sharply separated as in our time ; or perhaps 

 a few types of Cernay or of Puerco present some 

 mixed or inclusive characters which, at times, 

 render it difficult to attribute this or that genus to 

 the Creodonts or the Condylarthra, or to these last 

 or the Primates respectively. In any case, this efface- 

 ment of the limits between the orders, which so much 

 struck Dr. Lemoine in his excellent studies on the 

 Mammals of Cernay, seems to me to have been 

 singularly exaggerated by some pseudo-philoso- 

 phical paleontologists, who strive to see links every- 

 where, and thus run the risk of confusing everything. 

 It cannot be denied that the first fauna of Placental 

 Mammals known already shows very evident differ- 

 entiations in several directions, an important fact 

 which necessarily implies the earlier existence of 

 placental faunas still less differentiated, which we 

 may expect later on to discover far back in Second- 

 ary times. 



