Osteology cf the Chatham Island Snipe. €93 



which I should like to refer before commencing this account. 

 I have said that there is good reason to regard the Chatham 

 Island Snipe as an ancient and generalised form — apparently 

 the most generalised Snipe-like form of which we have any 

 evidence — and that its present habitat is ultra-southern. 

 Have we any right to assume, as is invariably done in other 

 like cases, that the present-day habitat of this the most 

 generalised Scolopacine form represents the centre of dis- 

 persal (or part of the original focus of dispersal) of the 

 Scolopacine race? In a recent and most interesting paper 

 on ''Climate and Evolution," Dr. W. D. Matthew (Annals 

 N.Y. Acad. Sci. vol. xxiv. 1915, pp. 171-318) has stated as 

 his opinion that such an assumption as regards generalised 

 members of other groups is " wholly illogical." " Whatever 

 agencies/' he says (p. 180)^ " may be assigned as the cause 

 of evolution of a race, it should be at first most progressive 

 at its point of original dispersal, and it will continue this 

 progress at that point in response to whatever stimulus 

 originally caused it and spread out in successive waves of 



migration At any one time, therefore, the most 



advanced stages should be nearest the centre of dispersal, 

 the most conservative stages farthest from it. In the same 

 way, in considering the evidence from extinct species as to 

 the centre of dispersal of a race, it has frequently been 

 assumed tliat the region where the most primitive member 

 of a race has been found should be regarded as the source 

 of the race, although in some instances more advanced 

 species of the same race were living at the same time in 

 other regions. The discovery of very primitive Sirenians 

 in Egypt, while at the same time much more advanced 

 ' Sirenians were living in Europe, has been regarded as evidence 

 that Africa was the centre of dispersal of this order. It is 

 to my mind (food evidence that it was not (italics mine). 

 .... it is much more correct to say that the modern 

 African fauna is of Tertiary aspect, and is in large part 

 the late Tertiary fauna of the nortliern world, driven 

 southward by climatic change and the competition of 

 higher types.-'^ 



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