400 



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



quently follows at the proximal end, while in some grains 

 it advances to the proximal end before gelatinization 

 starts at this end, a narrow band at the proximal end and 

 sides nearby proving the most resistant starch. In 

 grains with centric or nearly centric hilum the reaction 

 starts almost simultaneously at both ends. The process 

 advances from two ends towards the hilum in the major- 

 ity of grains, a narrow band of starch at either side just 

 distal to the hilum usually proving the most resistant. 

 In rounded grains the refractive border is sometimes 

 gelatinized without distortion. A fissure is found in 

 some grains which form the hilum previous to gelatiniza- 

 tion, and usually as the process approaches the hilum a 

 fissure is not present ; one is formed which then pushes 

 through the more resistant starch surrounding the hilum. 

 The gelatinized grains are swollen and much distorted 

 so that they do not resemble the untreated grain. 



The reaction with calcium nitrate begins in rare 

 grains in 1 minute. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains 

 and total starch in 5 minutes; slight progress in 15 

 minutes; in about 0.5 per cent of the grains and 1 per 

 cent of the total starch in 30 minutes; slight progress 

 in 45 minutes ; in about 1 per cent of the grains and 2 

 per cent of the total starch in 60 minutes. (Chart D 35.) 



The reaction with uranium nitrate begins in rare 

 grains in 1 minute. Complete gelatinization occurs in 

 about 0.5 per cent of the entire number of grains and 1 

 per cent of the total starch in 5 minutes; very slight 

 progress in 15 minutes; in about 1 per cent of the grains 

 and 2 per cent of the total starch in 30 minutes; little 

 if any further progress in 45 and 60 minutes. (Chart 

 D36.) 



The reaction with strontium nitrate begins in rare 

 grains in 1 minute. Complete gelatinization occurs in 

 less than 0.5 per cent of the grains and total starch in 

 5 minutes ; in about 0.5 per cent of the grains and 1 per 

 cent of the total starch in 15 minutes; in about 1 per 

 cent of the grains and 2 per cent of the total starch 

 in 30 minutes; in about 3 per cent of the grains and 

 5 per cent of the total starch in 45 minutes; in about 4 

 per cent of the grains and 7 per cent of the total starch 

 in 60 minutes. ( Chart D 37. ) 



The reaction with cobalt nitrate begins in very rare 

 grains in 1 minute. Complete gelatinization occurs in 

 much less than 0.5 per cent of the entire number of 

 grains and total starch in 5 minutes ; in still less than 

 0.5 per cent of the grains and total starch in 15 minutes; 

 in about 0.5 per cent of the grains and 1 per cent of 

 the total starch in 30 minutes ; little if any further prog- 

 ress in 45 and 60 minutes, respectively. (Chart D 38.) 



The reaction with copper nitrate begins in rare grains 

 in 1 minute. Complete gelatinization occurs in less than 

 0.5 per cent of the entire number of grains and total 

 starch in 5 minutes; in about 1 per cent of the grains 

 and 2 per cent of the total starch in 15 minutes; little if 

 any further progress in 30, 45, and 60 minutes, respec- 

 tively. (Chart D 39.) 



The reaction with cupric chloride begins in very 

 rare grains in 1 minute. Complete gelatinization occurs 

 in much less than 0.5 per cent of the entire number of 

 grains and the total starch in 5 minutes ; in about 1 per 

 cent of the entire number of grains and 2 per cent of the 



total starch in 15 minutes; little if any further progress 

 in 30, 45, and 60 minutes, respectively. (Chart D40.) 



The reaction with barium chloride begins in rare 

 grains in 1 minute. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains and 

 total starch in 5 minutes ; still but rare grains completely 

 gelatinized and the reaction begun in but few grains 

 in 15, 30, 45, and 60 minutes, at the end of which period 

 complete gelatinization still occurs in less than 0.5 per 

 cent of the grains and total starch. (Chart D 41.) 



The reaction with mercuric chloride begins in very 

 rare grains in 2 minutes. Complete gelatinization occurs 

 in less than 0.5 per cent of the entire number of grains 

 and total starch in 5 minutes; in about 0.5 per cent of 

 the grains and 1 per cent of the total starch in 15 min- 

 utes; in about 1 per cent of the grains and 2 per cent 

 of the total starch in 30 minutes; little if any further 

 progress in 45 and 60 minutes. (Chart D 42.) 



HlPPEASTRUM CLEONIA (POLLEN PARENT ). 



(Plate 1, fig. 8; Charts D 22 to D 42.) 



Histologic Properties. 



In form the grains are usually simple and isolated, 

 but a larger number of both compound grains and of 

 aggregates are observed in this starch than in that of 

 //. titan, and there are also a number of isolated grains 

 each having a large pressure facet at the distal end, no 

 such grains being observed in H. titan. The grains are, 

 as a rule, more rounded and more irregular than those 

 of H. titan. The irregularities are due to the following 

 causes: (1) Various shallow depressions in and flatten- 

 ings of the margin; (2) small nipple-like and larger 

 rounded and pointed projections; (3) some unequal de- 

 velopment of one part of the distal end. The conspic- 

 uous forms are: Ovoid (usually rather broad but with 

 one pointed end, although somewhat elongated forms and 

 forms with both ends blunt and rounded occur), plano- 

 convex and dome-shaped, round and nearly round, and 

 elliptical. There are also reniform, finger-like, trian- 

 gular, lenticular, and quadrilateral forms with rounded 

 corners. The chief differences in form between this 

 starch and that of H. titan are that the grains of this 

 starch are somewhat more rounded and more irregular in 

 form. The two starches resemble one another closely. 



The hilum, when not fissured, is not very distinct and 

 appears as a round or lenticular spot. It is fissured mod- 

 erately often, but probably not so much as the grains of 

 II. titan. The fissures take the following forms: (1) 

 A single, moderately straight line often with several small 

 fissures branching from it; (2) an occasional cruciform 

 or Y-shaped fissure. The hilum is often centric, but 

 usually eccentric, and the degree of eccentricity varies 

 from 0.45 to 0.25, usually 0.39, of the longitudinal axis. 

 The hilum is on the average less eccentric than in 

 H. titan. 



The lamellw are often indistinct, but are distinct on 

 more grains and more regular than was noted in the 

 starch of H. titan. When they can be seen they are 

 distinct, rather coarse bands usually having the form 

 of the outline of the grain, even when near the hilum. 

 They are usually continuous throughout the grain, but 

 occasionally only near the hilum, and in some grains 

 a few discontinuous lamella? may be seen surrounded by 

 several continuous ones. Those counted on the common- 



