'206 



THE POTATO. 



the roots of the Twitch or Couch grass will bore their way 

 through the roots of trees, and especially so through the 

 tubers of the potato. He further says that the roots will 

 force their way through discs of tinfoil. The roots of 

 the Couch grass are furnished at their tips with hard 



TUBEK PIERCED BY COUCH. 



scales, hence their power of penetration. The illustration 

 shows a tuber pierced through with a Couch root. 



These examples of mimicry, etc., in the potato are 

 given in this work to show that there is, apart from the 

 food value and cultural details, much also of general in- 

 terest connected with the " Monarch of the Mould." 



