484 



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



apparently being the most resistant. The capsule of the 

 gelatinized grain of this species appears heavier and less 

 distorted than that of the species studied. It is to be 

 noted that when the reaction in this species becomes 

 started, it is more rapid than in N. bowdeni, etc. 



The hilum is distinct, and a bubble is usually formed 

 there. The lamella; become distinct, especially those 

 which are not so fine as the greater number. A narrow 

 and not very refractive band is formed about the margins 

 of the grains. Gelatinization in most of the grains be- 

 gins first at several points on the distal margin and then 

 at the hilum and proximal end, and, in others, first at the 

 hilum and proximal end and then at the distal margin. 

 Gelatinization progresses smoothly from the proximal end 

 and from the distal end by serial separation and gela- 

 tinization of the lamella? and in most of the grains con- 

 tinues so until a part of the grain midway between the 

 hilum and the distal end is reached, then the margin on 

 either side is first rapidly gelatinized, and then the cen- 

 tral material, accompanied by a deep invagination of the 

 previously distended gelatinized proximal portion and of 

 the rather less distended gelatinized distal portion, a 

 process which leaves a crumpled mass to represent the 

 completely gelatinized grain. In other grains gela- 

 tinization proceeds smoothly from the two ends until the 

 hilum is reached from the proximal end, then a refrac- 

 tive furrow or central fissure extends rapidly from the 

 hilum distally, and as the portion along the course of this 

 fissure gelatinizes the more resistant material at the sides 

 and margin is split into two pieces, which then rapidly 

 gelatinize. The gelatinized grains are very large and 

 much distorted and do not show any resemblance to the 

 untreated grain. 



The reaction with calcium 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; in about 1 per 

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

 in 15 minutes ; in about 2 per cent of the grains and 4 per 

 cent of the total starch in 30 minutes ; in about 3 per cent 

 of the grains and 8 per cent of the total starch in 45 

 minutes ; in about the same percentage of the grains and 

 10 per cent of the total starch in GO minutes. (Chart 

 D203.) 



The reaction with uranium nitrate begins in 1 minute. 

 Complete gelatinization occurs in 0.5 per cent of the 

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

 in 5 minutes ; in about 1 per cent of the grains and 3 per 

 cent of the total starch in 15 minutes ; in about 3 per cent 

 of the grains and 9 per cent of the total starch in 30 min- 

 utes; in about 6 per cent of the grains and 19 per cent 

 of the total starch in 45 minutes; in about 18 per cent 

 of the grains and 28 per cent of the total starch in 60 

 minutes. (Chart D 204.) 



The reaction with st'ro?it;ium nitrate begins imme- 

 diately. Complete gelatinization occurs in about 4 per 

 cent of the entire number of grains and 58 per cent of the 

 total starch in 5 minutes; in about 55 per cent of the 

 grains and 90 per cent of the total starch in 15 minutes; 

 in about 86 per cent of the grains and 95 per cent of the 

 total starch in 30 minutes; in about 92 per cent of the 

 grains and 9G per cent of the total starch in 45 minutes; 

 in about 93 per cent of the grains and 99 per cent of the 

 total starch in GO minutes. (Chart D 205.) 



The reaction with cobalt 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; very little advance in 15 and 30 

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

 cent of the total starch in 45 minutes ; very little if any 

 further advance in 60 minutes. (Chart D 206.) 



The reaction with copper nitrate begins in a few 

 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 1 per cent of the 

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

 in about 4 per cent of the grains and 14 per cent of the 

 total starch in 30 minutes; in about 10 per cent of the 

 grains and 22 per cent of the total starch in 45 minutes ; 

 in about 14 per cent of the grains and 25 per cent of the 

 total starch in 60 minutes. (Chart D 207.) 



The reaction with cupric chloride begins in a few 

 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 0.5 per cent of the 

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

 in 15 minutes ; little if any further advance in 30, 45, and 

 60 minutes. (Chart D 208.) 



The reaction with barium chloride begins in 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 2 per cent of the total starch in 15 minutes ; 

 little if any further progress in 30, 45, and 60 minutes. 

 (Chart D209.) 



The reaction with mercuric chloride begins in a few 

 grains in 2 minutes. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 4 

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

 in 15 minutes; in about 2 per cent of the grains and 5 

 per cent of the total starch in 30 minutes; little if any 

 further advance in 45 and 60 minutes. (Chart D 210.) 



N/ERINE ELEGANS (POLLEN PARENT ). 

 (Plate 6, figs. 32 and 35; Charts D 190 to D 210.) 

 Histologic Properties. 

 In form the grains are usually simple and isolated, 

 but there are a few aggregates, linearly arranged, which 

 are not noted in N. crispa, and a few compound grains, 

 which have either 2 components as in N. crispa, or 3 or 

 even 4, which are noted in that starch. The grains are 

 more regular than in N. crispa, and any irregularities 

 which occur are due to the following causes: (1) Greater 

 development of one part of the distal end or of one side 

 than of the rest; (2) protuberances, which are not so 

 large as in N. crispa; (3) a small deep notch in the distal 

 margin, which is more common than in N. crispa; (4) a 

 deviation of the longitudinal axis with consequent bend- 

 ing of the grain; (5) secondary sets of lamellae whose 

 longitudinal axes are at varying angles with those of the 

 primary set The conspicuous forms are ovoid and elon- 

 gated elliptical, even among the small grains. There are 

 also triangular with rounded angles, irregularly quadri- 

 lateral with rounded angles, pyriform, and nearly round 

 shapes. In the grains of N. elegans usually the proximal 

 end is smaller than the distal end or both ends are of 

 equal size, and only occasionally is the distal end the 

 smaller as in the majority of the grains of N. crispa. 



