255 DR. J. W. HESLOP HARRISON ON 



Their uneven Geographical Distribution. 



One very striking feature of the rose hybrids we have con- 

 sidered thrusts itself upon us, and tliat is the manifest 

 inequality of their geographical distribution. For every 

 single hybrid shrub discovered in the South of England, 

 dozens have been detected in the North and in Scotland and 

 Ireland. As I have explained, this proceeds from the 

 nearness of mollis and pimpiiiellifolia in their flowering season, 

 and secondly from the lateness of spring in these latter areas 

 tending to mass, as it were, the periods for blossoming of all 

 the forms very close together. Great as this disparity is with 

 us, it is still further accentuated on the Continent. There, 

 rose hybrids of the patent type are extremely unfrequent, and 

 this, I think, depends on an exaggeration of the facts governing 

 their occurrence with us, involving a much more sharply 

 marked period of flowering in the ta.x\\QX pinipinellifolia, aided 

 by the restricted area inhabited by the northern Rosa mollis. 

 With a renewal of northern climatic conditions, as in Norway, 

 hybrids in the genus attain the same frequency as in the 

 northern portions of our island. Nothing could surpass the 

 magnificent set of mollis X pimpinellifolia hybrids I have 

 obtained from various stations in the west of Norway. 



Their Powers of producing Good Seed. 



Probably one of the causes leading to the tardy admission 

 of the hybrid nature of the forms discussed above was the 

 erroneous ideas which were current as to their fertility. This 

 fertility was so contrary to the preconceived notions of hybrid 

 sterility which held sway that it served to mask the real state 

 of affairs. To a very great degree the vogue of the idea, and 

 the failure of books to disclose the almost uniform barrenness 

 of recognised rose hybrids, arise from the fact that, as just 

 ■ shown, such hybrids are iiifinitely more prevalent in the north; 

 in consequence, they are usually cullecteil by visiting botanists 

 stiortly after the fall of the sepals. Then, owing to the effects 

 of heterosis and the exceptional display of flowers [)rovided by 

 the bushes, everything seems normal. Visit the same bushes 



