56 CONTACTS WITH DARWINISM IV [ch. vi 



local adaptation to local needs, except upon very large areas. 

 Would adaptation be likely steadily to follow a line based only 

 upon averages, in such circumstances ? It would hardly seem likely. 



U 4 cotton, one of the great successes of cotton breeding, was 

 locally bred at Barberton in the Transvaal for certain needs, and 

 has proved to be a superior cotton for an immense area. But a 

 Darwinian species would almost certainly be a species produced 

 upon a local area, and if it began to spread about in its early 

 stages it would be lost (as Fleeming Jenkin showed) by crossing 

 with its neighbours, a fate from which U4 was, of course, carefully 

 protected. 



Conditions other than those of climate or soil are hardly likely 

 to change continuously in one direction, except upon broad 

 general lines, such as a change from forest to grassland or vice 

 versa, and even this is probably determined by climatic change. 



There is another type of adaptation, which we may call 

 adaptation to movable conditions. A climbing plant will remain 

 adapted to climbing almost anywhere that there are erect plants, 

 so long as it is suited to the climate and other general conditions. 

 A water plant can travel over an immense area, finding suitable 

 conditions in innumerable places. The American pitcher plant, 

 Sarracenia, is now quite happily established in a bog near to 

 Montreux, and so on. 



Geographical distribution was also explained by the selec- 

 tionists as based upon adaptation. The better adapted species 

 were those that spread the furthest. But how did a species 

 become adapted, let us say in Asia Minor, to the conditions that 

 occur in New Zealand? It must be just a case of luck. If the 

 species were old, so that it had plenty of time to adapt itself 

 wherever necessary, and as in this case it would probably have a 

 good deal of capacity to withstand extremes, or adaptability, it 

 would probably be able to find places whose existence would 

 enable it to get across the vast distances. When at last it reached 

 New Zealand it would probably soon find places in which the 

 conditions were sufficiently like those just left to enable it to live 

 there. One would, perhaps, expect those plants that were 

 evolved in regions where there was great variety of conditions to 

 be those most likely to spread widely ; it may be so, but we have 

 at present no evidence to go upon. 



In dealing with the adaptation of a plant to changed conditions 

 man always tends to be in too great a hurry. When Europeans 

 first went to the tropics, they tried to acclimatise there the plants 



