VERTEBRATE PALEONTOLOGY IN 1910 661 



In connection with the above may be mentioned an article on 

 the continuity of development by Dr. W. D. Matthew, published 

 in the Popular Science Monthly for November 1910 (pp. 473-8). 

 After discussing the geological sequence and development of 

 the so-called " ruminating hogs," or oreodonts, in North 

 America, the author concludes that if we regard the record as 

 continuous where there is no apparent break, " and that the 

 known record really represents what was going on over the 

 entire continent of North America, I do not see that we can 

 fairly escape from the conclusion that new species, new genera, 

 and even larger groups have appeared by saltatory evolution, 

 not by continuous development. 



** But — and here lies the crux of the whole question — we have 

 no right whatever to make either of these assumptions. And 

 without them the argument from palaeontology for discontinuous 

 development is almost or quite worthless." 



Later on in the article Dr. Matthew makes the following 

 important observations with regard to the probable places of 

 origin of the oreodonts, the horses, and certain other groups : 



*' I assume that since the oreodonts and peccaries never 

 reached the Old World, and the camels did not reach it till the 

 Pliocene, their centres of dispersal were well to the south of the 

 Bering Sea connection with the Old World. I assume that since 

 the horses are represented by a double evolutionary series, one 

 in Europe, a closer one in North America, their centre of dispersal 

 lay far enough north to spread into Europe on the one hand, 

 and North America on the other, but that the latter was nearer 

 or more accessible, i.e. their centre of dispersal was north-eastern 

 Asia or Alaska. On similar grounds the centre of dispersal of 

 most of the Tertiary ruminants might be located in north-west 

 Asia, of rhinoceroses in north-east Asia and Alaska, of dogs 

 in north-west Canada." 



This suggestion as to the single dispersal-centre of the horse- 

 group in high latitudes seems, on the face of it, much more 

 probable than Professor Cope's theory that the group had a dual 

 origin and development, one in North America and a second in 

 the Old World. 



An important advance in our knowledge of the early Tertiary 

 fauna of the Fayum district of Egypt has been made by Dr. Max 

 Schlosser, who in the Zoologischer Anzeiger for 1910, vol. xxxv. 

 pp. 500-508 announced the discovery in the Oligocene of remains 



