714 



DATA OF PROPERTIES OF STARCHES OF PARENT- AND HYBRID-STOCKS. 



2G/J., in length and breadth. The common sizes are 24 

 by 18/j. and 20 by 19/*. 



Comparison of the histologic properties between B. 

 socotrana and B. double deep rose shows : 



Form: Compound grains which are sometimes seen 

 in B. double deep rose do not occur in B. socotrana, nor 

 are there any evidences of the existence of aggregates as 

 in B. double deep rose. The grains are more regular in 

 form than those of B. double deep rose, but when irregu- 

 larities occur they are more striking and more obvious 

 than in that starch. The irregularities are due to the 

 following causes, of which the first, second, and third 

 are more common than in B. double deep rose, and the 

 fourth and fifth much less common : ( 1 ) 1, 2, or more 

 large, rounded or pointed protuberances from the proxi- 

 mal end or sides; (2) a greater development of one part 

 of the distal end of the grain than of the rest; (3) a 

 deviation of the axis and a consequent bending of the 

 grain; (4) elevations and depressions of the margin, 

 especially at the distal end; (5) rarely a secondary set 

 of lamellae whose axis is at an angle with that of the 

 primary set. The grains are much more elongated in 

 form than in B. double deep rose, and the round or nearly 

 round forms so common in that starch are very rare in 

 B. socotrana. 



The hilum is as distinct as in B. double deep rose and 

 somewhat less rarely fissured. The fissures have the same 

 forms as described under B. double deep rose and in addi- 

 tion a somewhat branched Y-form. The hilum is usually 

 eccentric, 0.18 of the longitudinal axis, which is 0.08 

 more eccentric than is usual in B. double deep rose. 



The lamella are fine instead of somewhat coarse and 

 are not so distinct as in B. double deep rose. There is 

 usually not a broad refractive lamella near the hilum 

 as in B. double deep rose, but there are often 1 to 3 or 

 more broad, refractive lamella; which may be situated 

 about half the distance from the hilum to the margin and 

 which, in some grains, form a band at this point, but in 

 others are separated and divide the fine lamellae into bands 

 of varying breadth. The lamellae are much less numer- 

 ous than in B. double deep rose. 



In size the grains are commonly 30//. by 21/t and 32/j. 

 by 14;it, in length and breadth. These sizes are, respec- 

 tively, 10/t longer and 2/t broader, and 6ju longer and 

 4/i narrower, than the corresponding common sizes of 

 B. double deep rose. The larger grains also are 18/u 

 longer and 2/t broader than the elongated grains of 

 B. double deep rose. 



POLARISCOPIC PROPERTIES. 



The figure is moderately distinct and usually well 

 defined. The lines cross at an acute angle which varies 

 widely in size in the different grains. They are often 

 very much bent and moderately often are bisected. The 

 figure may have one or more extra lines, and there are a 

 number of multiple figures. 



The degree of polarization varies from moderately 

 low to high (value 50). In most of the grains it is 

 moderate, in a few moderately low, and in a few moder- 

 ately high to high. There is often considerable varia- 

 tion in a given aspect of an individual grain. 



With selenite the quadrants are usually moderately 

 clear-cut. They are unequal in size and often very irreg- 

 ular in shape. The colors are usually not quite pure. 



Comparison of the polariscopic properties between 

 B. socotrana and B. double deep rose shows : 



The figure is more distinct and more often well de- 

 fined than in B. double deep rose. The lines cross at an 

 acute angle which does not vary widely in different 

 grains, and they are much less often bent or bisected. 

 The figure never has one or more extra lines, and multi- 

 ple figures are rare. 



The degree of polarization varies from moderate to 

 high (value 60), 10 units more than in B. double deep 

 rose. There is very little variation in a given aspect of 

 the individual grains. 



With selenite the quadrants are more clear-cut, and 

 are more often regular than in B. double deep rose. 

 The colors are much more often pure than in that starch. 



IODINE REACTIONS. 



With 0.25 per cent Lugol's solution, the grains all 

 color a moderate blue-violet (value 45). The color 

 deepens rapidly until it is very deep and has assumed 

 a more bluish tint. With 0.125 per cent Lugol's solution 

 the grains all color a light violet tinged with blue and 

 the color deepens moderately rapidly until it is deep 

 and has assumed a more bluish tint. After heating in 

 water until all the grains are completely gelatinized and 

 then treating with a 2 per cent Lugol's solution, the 

 gelatinized grains are all colored a moderate indigo, and 

 the solution a deep indigo. If the preparation is boiled 

 for 2 minutes and then treated with an excess of a 2 per 

 cent Lugol's solution, the grain-residues are very lightly 

 to moderately lightly colored at the proximal end, the 

 capsules a moderate violet, and the solution a very deep 

 indigo. 



Comparison of the iodine reactions between B. soco- 

 trana and B. double deep rose shows : 



With 0.25 per cent Lugol's solution the grains all 

 color a light to moderate violet tinged with blue (value 

 30), 15 units less than in B. double deep rose. With 

 0.125 per cent Lugol's solution the grains are all very 

 lightly colored, much less than in B. double deep rose. 

 After heating in water until the grains are all gelatinized 

 and then treating with a 2 per cent Lugol's solution, the 

 gelatinized grains are colored a moderately light to deep 

 indigo, more than in B. double deep rose; and the solution 

 a deep indigo, less than in B. double deep rose. If the 

 preparation is boiled for 2 minutes and then treated 

 with an excess of a 2 per cent Lugol's solution, the 

 grain-residues are all colored a moderate indigo at their 

 proximal ends, more than in B. double deep rose; the 

 capsules a very deep violet, more than in B. double deep 

 rose; and the solution a very deep indigo the same as in 

 B. double deep rose. 



ANILINE REACTIONS. 



With gentian violet the grains color very lightly at 

 once, and in 30 minutes they are light to moderately 

 colored (value 40). The majority of the grains are 

 lightly to moderately colored, a few lightly, and a very 

 few deeply. 



With safranin the grains all color very lightly at once, 

 and in 30 minutes they are moderate to deeply colored 

 (value 60). The majority of the grains are moderate 

 to deeply colored, a few lightly, and a few deeply. 



Comparison of the aniline reactions between B. soco- 

 trana and B. double deep rose shows : 



