200 Sterile " Dtvarfs " in Humulus Lupulus L. 



since the " dwarfs " were treated as regards cultivation etc. from the 

 time of germination onwards in exactly the same way as the seedlings 

 which developed into normal plants. 



EXPLANATION OF PLATES. 



PLATE VIII. 



Fig. 1. Photograph taken in the Experimental Hop-garden at W^-e College, Kent, showing 

 the climbing bines of normal seedlings of H. Lupulus^ and, to the right, two "dwarf" 

 seedlings which have produced a large number of very thin stems all totally unable to 

 climb. These "dwarfs" are 7 years old. 



Fig. 2. Photograph as in Fig. 1 ; in the background can be seen the climbing bines 

 of normal seedlings, in the foreground a "dwarf" seedling, the most vigorous shoots 

 of which have climbed to a height of 5 feet. The leaves are cordate and simple, and 

 may be compared with those of the normal climbing plants shown in Fig. 1. 



PLATE IX. 



Fig. 3. Photograph of a "dwarf" seedling; the most vigorous shoots have climbed 2 feet. 

 The leaves are simple and cordate, and the stems thread-like. This "dwarf" is 

 7 years old. 



Fig. 4. A normal one-year-old seedling, starting the season's growth. 



Fig. 5. A "dwarf" one-year-old seedling, starting the season's growth. 



Fig. 6. A "dwarf " seedling at the end of its second year's growth. Natural size. 

 (This was one of many similar seedlings obtained in the '* cross" Canterbury White- 

 bine X male hop from Oregon, U.S.A.) 



