14 HOPS. 



out underground runners near and parallel to the surface, 

 which, when separated from the parent plant, are capable 

 of developing into independent stocks. Not infrequently 

 the rootstock obtains considerable dimensions, the diameter 

 varying, in the case of mature plants, between two and 

 three inches, whilst the roots extend downwards for a 

 distance of as much as thirteen feet. 



In the case of cultivated hops, the propagation of which 

 is exclusively effected by the vegetative method, artificial 

 rootstocks are produced by the separation of portions of the 

 parent plant, which new. stocks throw out from the vicinity 

 of the cut extremity and the adjacent parts a number of 

 adventitious rootlets, which behave in the same manner as 

 the roots of the seedling plant. The hop is particularly 

 long lived, especially the wild sorts, and is very difficult to 

 get rid of where it has once gained a footing in the soil ; 

 since even when the rootstock dies out in the course of 

 (20 to 30) years there always remains in the ground portions 

 of roots and stems capable of producing new plants. 



The rootstock is insusceptible to the influence of cold, 

 and will stand even the hardest winter without injury. It 

 is, however, more sensitive to prolonged wet weather and 

 mechanical injuries, which are frequent causes of destruc- 

 tion. Broadly speaking, the anatomical structure of the 

 hop root is identical with that of other dicotyledonous 

 plants. According to Fleischmann the total superficial 

 area of the roots of a mature hop plant measures about 

 860 square inches. 



The Stem and Leaves. 



In spring the plumule of the seedling hop and the buds 

 of the underground stem (or adventitious buds) of older 

 plants throw up- young shoots which appear above the sur- 



