xvi MUTATION, MENDELISM, ETC. 



way, 1 Batesonians are heedless of all investigation into 

 the geographical distribution of species and the changes 

 on the borders of their range. The Zoological Museum 

 at Tring is pre-eminent for exact and thorough re- 

 searches of this kind, and the conclusions to which they 

 lead are well expressed by Rothschild and Jordan: 

 ' Geographical varieties . . . represent various steps in 

 the evolution of daughter-species.' And again, with 

 special reference to the believer in discontinuity : ' Who- 

 ever studies the distinctions of geographical varieties 

 closely and extensively, will smile at the conception of 

 the origin of species per saltitm.' - 



Nor is there any reason to wonder at the confidence 

 felt by these naturalists. It is explained on pp. 50-4 of 

 this work how it is that the evolution which has occurred 

 in time is preserved in the distribution of certain species 

 in space. Bateson's observations lead him to certain con- 

 jectures as to what has happened in the past. The 

 student of geographical distribution is recording history ; 

 and it is in the geographical distribution of varieties 

 rather than in ' Variation ' that we do indeed see, and 

 that without the chance of failure, ' Evolution rolling 

 out before our eyes.' 3 



1 ' I am convinced that the investigation of heredity by experimental 

 methods offers the sole chance of progress with the fundamental problems 

 of evolution.' Bateson, in Report British Association, 1904, p. 579. It 

 must be the same restriction to a point of view which, with all its vast 

 importance, is limited, that led Bateson to maintain, on p. 575 of the 

 same Report, ' that the survey of terrestrial types by existing methods 

 is happily approaching completion.' These words will sound somewhat 

 ironical to any naturalist who has had to do with museums, and knows 

 something of the difficulty in getting material worked out. There are 

 unfortunately very few animal groups concerning which Bateson's 

 statement is correct. 



2 Nov. Zool., 1903, vol. x, p. 492. 

 8 Bateson, On Variation, p. 17. 



