The Mode of Inheritance of Semi-Sterility in tlu- Offspring of Certain Hybrid Plants. 329 



plaut throwing velvet. The high percentage of aborted ovules in LV-92 

 is only partly due to tlie abstraction of the best pods for seed from its 

 small crop. 



Pedi- 

 gree 

 No. 



PodG 



Aborted 

 ovules 



Percentage 

 of ovules 

 aborted 



Percentage of 

 ovules aborted 

 in distal half 



Percentage of 

 pods with no 

 aborted ovules 



LV- 199 



LV-42.^) 



LV-494 



LV-27 



LV-91 



LV-92 



LV-114 



LV-468 



LV-486 



LV-527 



LV-548 



LV-558 



LV-150 



LV- 167 



LV-236 



LV-273 



LV-326 



LV-364 



LV-80 



LV-113 



LV-279 



LV-4G1 



Normal 



Thus the percentage of aborted ovules seen in the dry pods varies 

 from a minimum of 9 to a maximum of 32 (omitting the black plant 

 LV-486) for the normal plants, and from a minimum of 36 to a maxi- 

 mum of 57 for the semi-sterile plants. So many genetic factors (prob- 

 ably more than twenty) segregate in the second generation of tliis 

 cross, and affect the nutiition of the plants; and there are so many 

 obvious cases of maladjustment due to factorial combinations wliich do 

 not suit the environment; that it is to be exi)ected that some fertile 

 plants should show a fairly high percentage of undeveloped ovules. This 

 non-development of ovules usually affects the basal ovules mostly. 

 Thus in the distal halves of the pods, the minimum is 2 and the maxi- 



