RAIN ON THE ROOT CROPS. 



16: 



clearly bearing witness on their very faces to the inter- 

 vention of insect agency. Even higher in this respect 

 are the stocks and gilI)^nowers, whose petals are raised 

 on long claws, so as to form a tube for the preservation 

 of the honey from minor flies and beetles. These and a 

 vast number of other garden plants or wild weeds arc 

 all shown by their common points of structure to be de- 

 scended from a single original ancestor ; and the pecu- 

 liarities which natural selection has stamped upon them 

 have in many cases been further developed or exagge- 

 rated by the action of man. In fact, it would almost 

 seem as though we had but to set an ideal before our 

 eyes, and then by constant selection to bring it about 

 bodily in the sphere of concrete reality. On the other 

 hand, wherever the natural tendencies exist, we may 

 produce very like effects in the most widely different 

 families. Thus the carrot docs not belong to the same 

 group as the turnips at all, but is a similar highly evolved 

 root of the extremely unlike parsley and chervil tribe ; 

 while the beet and mangel-wurzel are equally remote 

 by ancestry, being artificial products from the goosefoot 

 and spinach line of descent. 



