124 Mr. A. D. Darbishire. On Crossing Round wth [June 20, 
positive correlation between size of grain and number of component pieces. . 
The commonest types of grains are those with 4, 5 or 6 component pieces. 
Grains with 7 or 8 pieces are rarer; grains with 2 or 3 pieces are intermediate 
in frequency between those with 4, 5 and 6 on the one hand and 7 and 8 on 
the other. But whilst grains with 7 or 8 pieces are not much larger than 
those with 4, 5 or 6, grains with 2 or 3 are always conspicuously smaller than 
those with 4, 5 or 6. 
The average length of the grains is 0°0269 mm., the average breadth 
0°0248 mm. The average length-breadth index is 92°19; that is to say, 
the grains are, as a glance at fig. 2 shows, almost round. The above figures 
were calculated from measurements of 105 grains. 
There are also in wrinkled peas a number of very small single grains which 
can be distinguished from the pieces, into which the compound grains break 
up, by the fact that they are circular. They are always smaller than grains 
consisting of two pieces. Two of them are shown in fig. 2. 
Fig. 2.—Starch-grains of Wrinkled Pea Fic. 3.—Normal c-grain of Wrinkled Pea, 
(c-grains). together with occasional p-grain. — 
Lastly, I have found very rarely indeed, in examples of “ British Queen,” 
isolated p-grains, as shown in fig. 3. At first I thought these grains had been 
introduced by using a razor with which I had been cutting round peas. 
But after taking every precaution to guard against this, by immersing the 
razor in strong potash before using it, I still found them: so that I cannot 
but believe that they really occur in wrinkled peas. I have also found them 
“Telephone,” and in extracted wrinkleds. 
