ORIGIN OF ORGANIC FORMS 319 



leaves, in others the stem presents a turnip-like swelling, 

 in others the inflorescences turn into fleshy organs well 

 known to everybody. In a fourth kind the stem grows 

 tall, and hardens, so that sticks may be made out of it ; 

 in a fifth the leaves acquire a bright colour, and so on. 

 Obviously no one would ever suppose that the progenitor 

 of all these forms, and hence also the transitional form, 

 which serves as the link between them, possessed all 

 these characters. As a matter of fact the wild original 

 form of cabbage does not present a single one of these 

 extreme characters. It is therefore very possible that 

 in some cases the real connecting form should escape 

 our attention. But it is beyond doubt, nevertheless, 

 that in the majority of cases transitional forms between 

 species no longer exist, and, as has just been observed, 

 according to Darwin's theory this very absence of them 

 is one of the results of natural selection. For the sake 

 of clearness we shall again refer to a comparison with 

 artificial selection. When different varieties of cabbage 

 arose, people who cultivated them evidently began to 

 care for the most rare and extreme representatives of 

 the several kinds. The specialist in the cauliflower did 

 not worry about stems or leaves ; what he cared for was 

 only the inflorescence, which he desired to be large and 

 fleshy. A specialist in the decorative kind of cabbage 

 cared only about the colouring and the form of the 

 leaves ; one and the same plant could not produce at 

 the same time both a head and a walking-stick, and so 

 on. It is clear that plants which did not show an 

 extreme development of some special character, but 

 combined many of them less sharply defined, were no 

 longer cultivated, were even destroyed, and hence were 

 bound to disappear. Consequently the appearance 

 of more clearly defined representatives was inevitably 

 followed by the extermination of the less clearly defined, 

 as a result of which the connexion between extreme forms 

 would break down and a series of variations disconnected 



