122 



LOCK : STUDIES IN PLANT BREEDING 



1. — Offspring of F2, Series 1. 



Expt. 41. — Offspring of white grains (crossed with G. W. S.). 



Out of 31 plants examined 16 produced white grains only. 



whilst 15 yielded both black and white grains, the expectation 



being that about 25 out of 43 plants (the offspring of 25 per cent. 



of the total number of F^ grains) would yield white only. Of 



plants which yielded both black and white grains the following 



produced a sufficient number to allow of the proportion being 



determined. 



Table 17. 



l 

 ■•> 



3 



I 

 5 

 6 



7 



Black. 



269 

 117 



82 

 ■2:: I 



59 

 I.V.I 

 169 



Total omit- 855 



tinp v> i 



White. 



ISS 

 126 

 115 



87 



95 

 219 

 200 



<.n:i 



1.798 



47-8 



52 2 



There seems to be no way of accounting for number 4 of 

 table 17 except as the result of some kind of error. 



Expt. 42. — Offspring of black or blackish grains ( do. ) 



Among 24 plants 2 produced exclusively black grains 



(all sugary). The remaining 22 produced both black and 



white grains, the proportion being as follows in the case of 



ten of them. ( The rest produced only a few grains each.) 



Table 18. 





Per cent. 

 Black. 



78 

 73 



XI 



48 



47 



15 



to 



10 

 50 



in 

 77 

 16 



Per « i mi 

 White. 



21 -7 

 26 7 

 I 5 • ( i 

 .-.II 

 53 

 5 1 • 6 

 59-7 

 59 4 

 19-5 

 53' I 



53 • 3 



