F. L. Engledow 97 



• 



them may depend some of the most important components of " yield." 



Investigations to this end are being undertaken. [The comparative 



morphology of the " hairs " on different parts of the plant may, perhaps, 



afford indications as to localities in which " parallel " development is 



to be expected.] 



The undermentioned crosses supply data concerning the inheritance 



of type of rachilla. 



Cross No. 53. 



Russian Goldthorpe, No. 9 x Plumage 



2-row 

 Bristly 



2-row 

 Smooth 



F^ = four plants ; all bristly 



Fo = 188 plants. Bristly : Smooth = 144 : 44 



= 76-6%: 23-4% 



In this case the deviation from 3 : 1 expectation is less than half the 



standard error. 



Gross No. 32. 



Russian ChevaUier, No. 7 x Inerme 



2-row 

 Smooth 



K 2-row 

 I Bristly 



Fx = 2 plants ; both bristly 



I 



[The seeds of these plants were sown on separately and the ^2 

 families were designated 32/1 and 32/2.] 



I 

 F-i 32/1 = 299 plants. Bristly : Smooth = 220 : 79 

 32/2=194 plants. Bristly : Smooth = 149 : 45 



F^i Total=493 Bristly : Smooth = 369: 124 



i.e. Bristly : Smooth = 74-8% : 25-2 7o 



In this case the deviation from the 3 : 1 expectation is far less than 



the standard error. 



Gross No. 57. 



Praecox x Plumage 



6-row / I \ 2-row 



Bristly ( ( Smooth 



i**! = 3 plants ; all bristly 



I 

 i*'2 = 186 plants. Bristly : Smooth = 146 : 40 



This suggests, but is by no means closely in accordance with a 3 : 1 

 ratio. Observation and theory compare thus : 



