18 



The Female Flowers. The female flowers occur in definite 

 inflorescences (strobiloid spikes), which are borne on branches 

 arising directly from the leaf axils of the main stem itself, or from 

 the axils of the leaves upon lateral shoots produced by the main 

 stem. These inflorescences give rise to the hops of commerce. 



Each female flower is very minute and consists of a cup-shaped 

 perianth, partially surrounding the superior ovary, which contains a 

 .-single ovule, and which is surmounted by two long stigmas covered 

 with elongated papillae (4, 5, Frontispiece). At this stage (as a rule 

 early in July) the hops are said to be " in burr." After the stigmas 

 or " brush " of the young hops drop off there is a rapid growth of the 

 bracts of the strobile, giving rise to the fir cone shape of the 

 mature inflorescence (7, Frontispiece). The bines are now said to 

 be " in hop." 



During the " growing out " period, which usually lasts about 

 five weeks, it will be observed that there are two very distinct 

 kinds of bracts in the strobile. At the four corners of the hop 

 occur the seedless stipular bracts (7, Frontispiece), which are further 

 distinguished by their greenish colour, the limited development of 

 lupulin glands and their acuminate apex. On the flat sides the 

 rounded, bright yellow, seed-bearing bracteoles* (6, 7, Frontispiece) 

 occur in pairs. 



While carrying out the various cross-fertilisation experiments, 

 described in the second part of this paper, during the past summer, 

 it was noticed that the young hops which were not pollinated, and 

 which served as check experiments or controls, always remained in 

 burr for a much longer period (often more than a week) than those 

 which were pollinated. On the other hand, it was found that when 

 the young hops were artificially pollinated, the brush turned brown 

 and withered in three or four days and then fell off. The dying 

 away of the stigmas was at once followed by the growth in size of 

 the young hops. In a word, the pollinated hops started to grow 



* The stipular bracts and bracteoles of the hop are spoken of as " petals " by 

 the hop growers in Kent. 



