.198 THE SURVIVAL OF THE UNLIKE. [vill. 



thistle finds its match in certain wild plants. The 

 report of the ' ' Russian Cactus Committee ' ' of North 

 Dakota declares that "our native grasses will entirely 

 exterminate the cactus, abundant proof of which can 

 be seen in many once cultivated but now abandoned 

 fields where the cactus has completely disappeared." 

 What was accomplished by these disputatious wild 

 plants can be always accomplished by judicious crop- 

 ping when new weeds attempt to usurp the land ; and 

 if this judicious cropping is already in practice, the 

 weeds will never gain a considerable foothold, and will 

 not attract attention. 



All these remarks concerning the relation of weed- 

 iness to farming are well illustrated by the methods 

 advised by the best authors for the destruction of 

 weeds. The leading "methods of weed destruction" 

 recommended by Professor Shaw's recent book upon 

 weeds are as follows : 



"The modification (when necessary) of the scheme 

 of rotation that has been adopted, so that such crops 

 as allow the seeds of the weeds which infest them to 

 ripen may, for a time, be omitted from the rota- 

 tion." 



The growing of hoed crops upon the farm 

 infested, to the largest extent that is practicable." 



"The growing of clover and lucerne, so far as this 

 can be done with profit." 



"The growing of soiling crops, to the extent that 

 may be found practicable, both because of the fa<*t that 

 they can be cut almost at dny time that is desirable, and 

 also because of their 'smothering' properties." 



The keeping of the land of the farm constantly at 

 work." 



