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THE AMERICAN MUSEUM JOURNAL 



probability both views were correct, the Pelycosaurs being a side branch 

 from a direct line very near to the early mammalian ancestors, the Cyno- 

 donts being probably the immediate ancestors of the mammal. 



Baur who worked here in America and died some fifteen years ago, was in 

 favor of the reptile origin. Seeley adopted a rather curious view. He 

 believed that the egg-laying mammals came from reptiles but that other 

 mammals arose from amphibians. On the whole the Germans have favored 

 the amphibians as ancestors, while English opinion although somewhat 

 divided, has mainly been in support of the reptilian theory. The majority 

 of Americans, doubtless influenced by Cope and Osborn, have always favored 

 the descent of the mammals from a reptilian ancestor. 



I became interested in the question in 1885 and practically resolved then 

 that I would contribute what I could to the solution of the problem. In 

 1892 I went to Australia and spent some years in studing the egg-laying 





" U I) V 



£.> •;_•-*; Ss* 



Pareiasaurus serridens Owen. A restoration of a skeleton founded on the specimen in 

 the South African Museum. Though not a mammal-like reptile it resembles them in having 

 powerful limbs and the body lifted off the ground. The skeleton is from eight to nine feet 

 in length and stands about three and one-half feet high 



mammals and marsupials. In 1897 I went to South Africa and have been 

 working in that region for the last seventeen years. In these seventeen 

 years nearly every specimen that has been picked up there has passed 

 through my hands. 



We call our South African deposits the Karroo formation — naming it 

 from the Karroo desert — and there is probably none in the world of greater 

 interest. This formation is extensive, covering the greater part of the 

 interior of Cape Colony, almost the whole of the Free State and much of 

 the Transvaal, Basutoland and Natal, an aggregate area of 200,000 square 

 miles. The formation is composed of bluish shales much like slate in color 

 and of mudstones and there is little doubt that it has been formed of the 



