io6o LIFE : OUTLINES OF GENERAL BIOLOGY 



of agriculture. On the other hand, "while man lops off giants at the 

 head of the scale, he adds insignificant pigmies at the bottom", 

 partly by carelessness, as in the case of rats and cockroaches, partly 

 by thoughtlessness, as in the case of rabbits in Australia or sparrows 

 in the States. 



METHOD OF NATURALISATION.— What should man do when 

 he wishes to naturalise a valuable plant or animal in a new and 

 markedly different country? If trial has shown that naturalisation 

 is not easy, the transporter should work with those varieties which 

 seem most likely to be suitable. Attention should also be paid to 

 the quality of variability, for some stocks are much more fixed than 

 others. It may be useful to transport individuals of the most pro- 

 mising stocks to some intermediate station, where selection may 

 be made among the variations that continue to arise. Darwin noted 

 that "Merino sheep bred at the Cape of Good Hope have been found 

 far better adapted for India than those imported from England". 

 {Variation, 1868, p. 305.) In cases where success in the new country 

 seems to depend on the possession of a particular character, such 

 as thick fur or woolly leaves, the variants selected would be those 

 tending most markedly in that direction, but Mendelian methods 

 might come to the breeder's aid and enable him to "graft" on to the 

 tentative imports the desirable character in question if it existed 

 elsewhere in an allied race. By more systematic selection of heritable 

 variations and by Mendelian hybridising, it seems likely that the 

 process of acclimatisation might be greatly extended and hastened. 



Willis notes (1922, p. 28) that man has often failed in naturalisa- 

 tion by attempting too much abruptly. Learning from failure, he 

 is now trying gradual transitions, "as in the way he has treated 

 Liberian coffee in Java, taking the seed of successive generations 

 a few score yards higher up each time, till he has persuaded the 

 tree to do well at a much higher elevation than that to which it is 

 naturally suited." 



The attempts to acclimatise the beautiful Cyperus papyrus in the 

 Ceylon Botanic Garden failed when seed from Europe was used, 

 but seed from Saharanpur in India succeeded at once. The moral 

 is that man must moderate his impatience and take a hint at least 

 from Nature's operations — by small steps throughout long periods. 



ADAPTATIONS 



Since organisms do in most cases succeed in persisting genera- 

 tion after generation, for longer or shorter cycles of years, they are 

 obviously fitted or adapted to the normal conditions of their life. 

 In other words, an organism is an integrate of many adaptations — 

 "a bundle of fitnesses", it has been called. But the term adaptation 



