ON THE APPEARANCE OF STERILE 'DWARFS" 

 IN HUMULUS LUPULUS L. 



By E. S. salmon, F.L.S., 

 S.E. Agnc. College, Wye, Kent 



In a large number of " crosses " which I have made during the past 

 seven years between different cultivated female varieties of hops and 

 various individual male hops\ some of the resulting seedlings are 

 remarkably distinct in character from either parent. The distinguish- 

 ing features of these seedlings are (1) their total, or almost total, 

 inability to climb; and (2) their complete sterility, no flowers being 

 produced. 



With reference to the first character, we find that in these abnormal 

 seedlings the strong relatively thick climbing stems (" bines ") which in 

 the normal male or female hop-plant arise annually from the perennial 

 rootstock are replaced by a number (often a very large number) of 

 weak, thin, sometimes almost thread-like stems, of limited growth, 

 which are either totally unable to climb, or climb weakly a short 

 distance. In many of these abnormal seedlings — which may con- 

 veniently be termed "dwarfs" — all the shoots either grow prostrate 

 on the surface of the ground or form an erect bush-like gi-owth about 

 1 foot high ; in other cases the longest shoots if provided with a piece 



^ Prof. J. Percival {Agric. Botany (1902), p. 335) writes: " ...the male [bop] is always 

 practically a wild form, for on account of their being of no use to the grower, males have 

 never been subject to special selection and improvement. It is somewhat curious that 

 although female seedhngs show considerable variation, we have never seen any morpho- 

 logical differences among males, no matter what their origin, except in one or two solitary 

 instances where the 'bines' were a paler colour than usual." This statement is somewhat 

 misleading, since we find in the forms, or varieties, of the male hop quite as much varia- 

 tion in such characters as the colour of the stem and petioles, length of the lateral 

 branches, and in other vegetative characters as in the female hop-plant. 



