The Making of Species 



sport. Similarly, white animals appear not to 

 give rise to colour varieties. 



We are never surprised to find that an ordi- 

 nary upright plant produces as a sport or muta- 

 tion a pendulous, or fastigiate form. These 

 aberrant varieties, be it noted, occur in species 

 which belong to quite different orders. 



De Vries points out that laciniated leaves 

 appear in such widely separated trees and shrubs 

 as the walnut, the beech, the hazel-nut, and the 

 turnip. 



Another example of the definiteness of varia- 

 tion is furnished by what Grant Allen calls the 

 " Law of Progressive Colouration " of flowers. 



On pp. 20, 21 of The Colours of Flowers, 

 he writes, " All flowers, as we know, easily sport 

 a little in colour. But the question is, do their 

 changes tend to follow any regular and definite 

 order? Is there any reason to believe that the 

 modification runs from any one colour toward 

 any other ? Apparently there is. ... All 

 flowers, it would seem, were in their earliest 

 form yellow ; then some of them became white ; 

 after that a few of them grew to be red or 

 purple ; and finally a comparatively small number 

 acquired the various shades of lilac, mauve, violet, 

 or blue." 



So among animals there are many colour 

 patterns and structures that appear in widely 

 different genera, as, for example, the magpie 



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