PLANT HYBRIDIZATION BEFORE MENDEL 115 



Regarding his own crossing Shirreff says : 



"One of my first attempts at crossing was made with April and Tala- 

 vera varieties, the latter being the pollen parent." 



Regarding the hybrid he says : 



"The plant from cross-fecundation appeared to be an intermediate 

 between the breeders." {ib., p. 28.) 



Between Shirreff's first and second attempts at the crossing of 

 wheat a period of nearly twenty years intervened. 



The technique developed by Shirreff in his wheat crossing ex- 

 periments is further described as follows : 



"The valves of the chaff were opened, and the anthers removed one 

 by one with the point of a needle. Three or four days afterwards, accord- 

 ing to the state of the weather, the valves of the chaff were again opened, 

 and the stigma touched with a camel's-hair brush covered with pollen 

 from the anthers of the male breeder. From the opening and closing of 

 the chaff valves," Shirreff says, "they frequently dropped off after fe- 

 cundation had been effected ; and scarcely one attempt in ten ended suc- 

 cessfully until the method described at page 21 was adopted, which so 

 changed matters that three attempts out of four proved successful." 

 {ib., pp. 29-30.} 



"For some time," Shirreff says, "my cross-fecundations produced noth- 

 ing very striking, until a variety in my comparative trial-plot attracted 

 notice, from the size of ear, and the length and strength of the straw, 

 when ripe, the grains were found to be fine in quality, and it was de- 

 cided to raise a stock from it for field practice." (ib., p. 31.) 



The variety in question was produced by crossing "Shirreff's 

 Bearded White" with pollen from "Talavera," with a view to 

 enlarging the seeds of the Bearded White, which were small and 

 round. The hybrid was called "King Richard," and was found 

 to be intermediate between the parents in form of ear, while ap- 

 proaching the Talavera in size and form. In tillering habit it was 

 intermediate. 



Shirreff, of course, knew nothing of the laws of segregation, 

 and a hybrid once obtained was for him always a hybrid. The 

 "mixed ears," spoken of as appearing in the progeny, were prob- 

 ably the segregating forms. Shirreff s^ys : 



"These mixed ears in all probability are owing to the hybridous 

 origin of King Richard, and are not likely to be got rid of without rais- 

 ing a stock again from a single grain, and when necessary doing so again 

 and again." {ib., p. 31.) 



By such selection he originated a new strain called "King Red 

 Chaff White," which was exhibited in bulk for the first time in 

 1870. Regarding it he says: 



