WEED MIGRATION 703 



In their own wild homes, likewise, these and scores of other 

 species are almost as sensitive to change as when forced by man 

 into an unappreciated state of culture. The simple cutting of the 

 forest is to most of these plants disastrous, though such of them 

 as are very hardy will often linger until fire has swept the cleared 

 land and burned out the tinder-like humus. After the fire comes 

 a complete change of vegetation, and, during the interval before 

 the stumps are finally removed and the land turned by the plow, 

 the clearing too often becomes a tangle of fire cherry (Prunus 

 pennsylvaniea) , aspens (Populus tremuloides and P. grandidentata) 

 and other quick-growing trees and shrubs with a liberal mixture 

 of blackberry and raspberry bushes, fire weeds (Epilobium and 

 Erechtites), rattlesnake-weeds (Prenanthes) , and other coarse 

 plants which love the open and the direct sunshine. When the 

 final planting of the farm crop comes, however, these sturdy plants 

 of the burned land are quickly disposed of and rarely if ever do 

 they make themselves troublesome in the cultivated field. 



E. W. Claypole, in speaking of the migration of weeds to 

 America, says: 



Underneath the great wave of human emigration from the so- 

 called Old to the so-called New World, underneath the noisy, busy 

 surface tide that has swept westward from the shores of Europe 

 to those of America during the last two hundred years, there has 

 existed another and a less conspicuous wave, another and a less 

 prominent tide of emigration. Westward in its direction, like the 

 former, it has silently accomplished results that seldom strike 

 the superficial eye, but yet are scarcely less in magnitude than 

 those which have followed the advent of the white man to the 

 shores of America. 



I allude to that slow and noiseless immigration of European 

 plants which has been going on for many years, and which prob- 

 ably commenced when the first European vessel touched our shores. 

 Side by side with the displacement of the red man by the white 

 man has gone on the displacement of the red man's vegetable com- 

 panions by plants which accompanied the white man from his trans- 

 Atlantic home. Not more completely have the children of the 

 pilgrim fathers made themselves at home on the banks of the 

 Charles and the Neponset, not more completely have the successors 

 of Champlain and Jacques Cartier established themselves along 

 the St. Lawrence, not more completely have the descendants of 

 the aristocratic colonists of Maryland and Virginia appropriated 

 the shores of the Chesapeake, than have the homely weeds of Eng- 

 land and France made themselves at home in the New World: 

 established themselves on its soil, appropriated its fields, its gar- 

 dens and its waysides. Nor have the older states alone been seized 

 by those European invaders. The stream has flowed beyond them, 

 and as no village or hamlet in the west is without its population 



