Evolution Going On 189 



remember that they are all scions of the not very promising wild 

 cabbage found on our shores. And are not all the aristocrat 

 apple-trees of our orchards descended from the plebeian crab- 

 apple of the roadside? We know far too little about the pre- 

 cise origin of our cultivated plants, but there is no doubt that 

 after man got a hold of them he took advantage of their varia- 

 bility to establish race after race, say, of rose and chrysanthe- 

 mum, of potato and cereal. The evolution of cultivated plants is 

 continuing before our eyes, and the creations of Mr. Luther 

 Burbank, such as the stoneless plum and the primus berry, the 

 spineless cactus and the Shasta daisy, are merely striking in- 

 stances of what is always going on. 



There is reason to believe that the domestic dog has risen 

 three times, from three distinct ancestors a wolf, a jackal, and 

 a coyote. So a multiple pedigree must be allowed for in the 

 case of the dog, and the same is true in regard to some other 

 domesticated animals. But the big fact is the great variety of 

 breeds that man has been able to fix, after he once got started 

 with a domesticated type. There are over 200 well-marked 

 breeds of domestic pigeons, and there is very strong evidence that 

 all are descended from the wild rock-dove, just as the numerous 

 kinds of poultry are descended from the jungle-fowl of some 

 parts of India and the Malay Islands. Even more familiar is 

 the way in which man has, so to speak, unpacked the complex 

 fur of the wild rabbit, and established all the numerous colour- 

 varieties which we see among domestic rabbits. And apart from 

 colour-varieties there are long-haired Angoras and quaint lop- 

 eared forms, and many more besides. All this points to evolu- 

 tion going on. 



The Romance of the Wheat 



It is well-known that Neolithic man grew wheat, and some 

 authorities have put the date of the first wheat harvest at between 

 fifteen thousand and ten thousand years ago. The ancient civili- 



