32 THE CONTROL OF LIFE 



§ 2. The Idea op Controlling Life 

 For ages before Darwin's day, it had been the practice 

 of shrewd men to look out for ' sports ' among dogs and 

 horses, pigeons and poultry, and so on ; or for * novelties' 

 among apples and roses, cereals and cabbages, and so 

 on. These sports and novelties, whose origin still 

 puzzles the biologist, were used as the starting-points 

 of valuable breeds of animals and varieties of plants. 

 The secret of domestication seems to have been lost, 

 though it may be that the number of domesticable 

 animals was never large ; but the practice of improving 

 breeds and making new breeds of domesticated animals 

 has been for a long time familiar, as in the case of cattle, 

 horses, sheep, dogs, and poultry. Additions to the 

 number of cultivated plants have continued into modern 

 times and the improvement of old-established races has 

 never ceased. 



But the theoretical side of this control was slow of 

 being discerned. There was no vivid realisation of the 

 fact that all the aristocrats of the apple-orchard are 

 the descendants of the sour plebeian crab-apple of the 

 wayside, or that all the quaint fantails and pouters, 

 turbits and tumblers of the dovecot are the descendants 

 of the rather conventional rock-dove {Columba livia) 

 of the shore-cliffs. The significance of what cultivator 

 and breeder had achieved was not appreciated till it 

 was seen in the light of Darwin's generalisation, that 

 the present has evolved from the past, that the factors 

 in the process are discoverable and like those in operation 

 now. In the light of this, it could not but occur to 



