528 WHITE— STUDIES OF INHERITANCE IN PISUM. 



or more divisions or separate irregularly shaped small particles 

 cemented together by a yellowish substance which is not colored 

 blue by iodine (19). The most common grains are 4-6-particled. 

 Both Kappert (48) and Darbishire (19) occasionally found potato- 

 shaped grains similar to those of round-seeded peas among the com- 

 pound starch grains. Small round grains are always present. Kap- 

 pert (48) found the starch grains of very young peas (2-3 weeks 

 old) to be free from splitting, and through observations on later 

 stages, he found all gradations from simple round grains to the 

 characteristic compound or radially split grain of 2 to 8 particles. 

 This led him to conclude that compound starch grains are simply 

 radially split simple starch grains and with only one starch for- 

 mation center instead of 2 to 8 such centers as is commonly sup- 

 posed. The so-called compound grains may be further broken up 

 through the action of diastase and this led Kappert to believe the 

 starch of wrinkled peas was more soluble than that of smooth- 

 seeded peas, a supposition made more plausible through the greater 

 amount of sugar and dextrine present. 



Both Gregory (37) and Darbishire (19) found the compound 

 starch grains of the wrinkled peas they studied to be smaller than 

 the starch grains of smooth-seeded peas. 



The data from measurements of several varieties are given 

 below : 



Investigator. Variety. 



Diameter. 



No. Grains Measured. 



Gregory (37) Several 



Darbishire (19) iBritish Queen 



Kappert (48) jGoldkonig. . . . 



.06-.2 mm. 

 .0248-.0269 mm. 

 .0245-.0268 mm. 



105 

 20 



The breadth-length index for starch grains of wrinkled peas of 

 course is higher being 92.2 for British Queen and 91.5 for Gold- 

 konig. 



Denaiffe (23), Darbishire (19), Kappert (48) and others all 

 agree that more water is taken up by dry wrinkled peas than by 

 smooth peas. Chemical analyses as given by Kappert show that the 

 water content of the air dry smooth and wrinkled peas differs only 

 by I or 2 per cent, in favor of the former. However, fresh wrinkled 

 peas before they are ripe are said to have possibly as high as 8 per 



