534 WHITE— STUDIES OF INHERITANCE IN PISUM. 



grains. From these facts, Darbishire holds the intermediate .lature 

 of the F^ starch grains is not responsible for the intermediate ab- 

 sorptive capacity of the F^ seed. High and low absorptive capacity 

 is to be regarded as a separate pair of characters. Darbishire has 

 not shown, however, that wrinkled Fj seeds differ markedly in ab- 

 sorptive capacity, which should be the case, unless the character of 

 the wrinkled pea completely masks any such difference in absorptive 

 capacity. 



Kappert (48), working over the same problems, secured results 

 only partially agreeing with those of Darbishire. He agrees with 

 Darbishire as to the intermediateness in form and constitution of 

 the starch grains and the absorptive capacity of the Fj seeds. He 

 also finds great variation in absorptive capacity of the Fj round seeds, 

 but offers a choice between two explanations — differences in en- 

 vironmental influences during development owing perhaps to posi- 

 tion of seed in the pod, or Darbishire's interpretation. Kappert 

 finds this variation in water absorptive capacity true of round peas 

 in the same pod in pure round-seeded varieties as well as in round- 

 seed segregates, and this is true when only seeds of same size, weight, 

 etc., are considered. Denaiffe, Darbishire and Kappert all agree 

 that wrinkled seeds in general have a higher water absorptive 

 capacity than round smooth peas, and hence there must be a close 

 correlation of some sort between the character of the starch and 

 ability to take up water. Both Darbishire and Kappert found the 

 water absorptive capacity of F^ peas to be nearer that of the round 

 smooth parent, while the starch grains should be considered as more 

 nearly approaching the wrinkled type, except in Kappert's crosses 

 involving " Laxton's Vorbote " (round smooth) and " Goldkonig " 

 (wrinkled). In these crosses, the F^^ starch was very similar to 

 " Laxton's Vorbote." 



Kappert finds no grounds for Darbishire's statement that both 

 simple and compound starch grains are found in about equal propor- 

 tions in Fi seeds, but thinks the starch grains Darbishire took for 

 simple were split on the narrow side, which Darbishire would have 

 noted if he had turned them over, as Kappert himself has done re- 

 peatedly. Splitting of starch grains, according to Kappert, may 

 take place fortuitously and not necessarily because of an inherent 



