408 ORIGINATIVE FACTORS IN EVOLUTION- 



distinct and relatively well-adapted species. The first ques- 

 tion has to do with primary or originative factors ; the second 

 has to do with secondary or directive factors. It may well 

 be, however, that the discontinuity of species depends more 

 on originative than on directive factors. 



A good many years ago there was born in a normal North 

 of Scotland family a child who grew up to be a wise and 

 well-proportioned dwarf. He married and had children 

 a certain number of whom were dwarfs. The peculiarity 

 re-appeared in grandchildren and great-grandchildren, and 

 one of the fourth generation was recently at the head of a 

 successful business a wise and well-proportioned dwarf. 

 The question before us, discussible if not answerable, is, 

 What conditioned the dwarf? This is the fundamental prob- 

 lem of the origin of the distinctively new. Whether it be 

 a clever dwarf, a mathematical genius, a 10-foot tailed 

 cock, a copper-beech, a Greater Celandine with laciniate 

 leaves, the general problem is the same, the old problem of 

 new departures. What are the originative factors in organic 

 evolution ? 



2. Variations Distinguished from Modifications. 



A problem so difficult demands cautious handling. The 

 first question is as to the nature of the novelties that actually 

 occur; and the sound procedure is to take stock of all observed 

 peculiarities or differences marking off individual organisms 

 of the same kind. These " observed differences " must be 

 measured and registered without theory or prejudice. We 

 compare the colour of the trout we catch from different 

 streams, the various numerical relations of radial canals and 

 sense-organs in a thousand jellyfishes of the same species, 

 the plumage in a score of ruffs, the number of vertebrae in 



