and birds appeared, numerous, varied and strange saur- 

 ians inhabited land and sea; but "witli the end of the chalk- 

 period most saurians seem to have vanished suddenly from 

 the scene, and soon we behold the mainlands and oceans 

 inhabited by mammals of most diverse kinds." The saur- 

 ians have become almost extinct and the mammal-tribe 

 suddenly shows a most extraordinary variability and power 

 of development. How is either phenomenon to be ex- 

 plained? 



"The disappearance of a group oi organisms has been 

 preferably explained since the time of Darwin, by defeat in 

 the struggle with superior competitors. If ever an expla- 

 nation lacked pertinency, it does so in this case, in which 

 the succumbing group is represented by gigantic and well 

 preserved animal forms, widely distributed and accustomed 

 to the most varied methods of nutrition, whereas the com- 

 petitor appears in the form of small, harmless marsupials. 

 It would be equivalent to a struggle between the elephant 

 and the mouse." /ly]J -fwt A'L^yu.iitt \,o^-v^ ■ 



We acknowledge with pleasure this clear rejection of 

 Darwinism on the part of Steinmann. 



Steinmann also rejects the natural extinction of those 

 forms, perhaps from the weakness of old age; whether he 

 is wholly warranted in doing so, seems somewhat doubtful. 

 He tries to explain the phenomenon on the basis of the 

 multiple origin of the mammals ; and in fact there is already 

 speculation regarding triple origin, viz: tambreets, mar- 

 supials, and the other mammals. Now if the latter also 



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