678 



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



The reaction with cobalt nitrate begins immediately 

 in a few smaller grains and in rare larger 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 min- 

 utes; in about 2 per cent of the grains and 3 per cent 

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

 advance is observed in 45 and GO minutes. (Chart 

 D479.) 



A few of the smaller grains are quickly gelatinized, 

 while very few of the larger grains, probably not more 

 than 0.5 per cent, are gelatinized in 60 minutes. 



The reaction with copper nitrate begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 2 per cent of the entire number of grains and 3 

 per cent of the total starch in 5 minutes; in about 3 per 

 cent of the grains and 4 per cent of the total starch in 

 15 minutes; in about 4 per cent of the grains and 6 per 

 cent of the total starch in 30 minutes ; in about the same 

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

 in 45 minutes; in about the same percentage of the 

 grains and 8 per cent of the total starch in 60 minutes. 

 (Chart D480.) 



The reaction with cupric chloride begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 2 per cent of the entire number of grains and 3 

 per cent of the total starch in 5 minutes ; in about 3 per 

 cent of the grains and 5 per cent of the total starch 

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

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

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

 starch in 45 minutes; in about the same percentage of 

 both grains and total starch in 60 minutes. (Chart D481.) 



The reaction with barium chloride begins in a few 

 small grains immediately. Complete gelatinization occurs 

 in about 0.5 per cent of the 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 3 per cent of the 

 total starch in 30 minutes ; little if any further advance 

 in 45 and 60 minutes. (Chart D482.) A few of the 

 smaller grains and an occasional medium-sized grain are 

 gelatinized, the larger typical grains being slightly if 

 any gelatinized by the reagent. 



The reaction with mercuric chloride begins in a few 

 of the smaller grains immediately. Complete gelatiniza- 

 tion occurs in about 3 per cent of the entire number of 

 grains and 4 per cent of the total starch in 5 minutes ; 

 in about the same percentage of the grains and 5 per cent 

 of the total starch in 15 minutes; in about 4 per cent 

 of the grains and 6 per cent of the total starch in 30 

 minutes; little if any advance in 45 and 60 minutes. 

 (Chart D 483.) Only the smaller grains and rare grains 

 of medium size undergo complete or partial gelatin- 

 ization. 



Gladiolus tristis (Pollen Parent). 



(Plate 20, fig. 116; Charts D 463 to D 483.) 

 Histologic Properties. 

 In form the grains are simple and appear as separated 

 grains of aggregates, or arranged either in partially disin- 

 tegrated or rare complete aggregates of from 2 to 4 com- 

 ponents. Doubtless aggregates of more components have 



existed, since polygonal grains with at least 5 angles are 

 found. A few originally simple isolated grains are pres- 

 ent. No compound grains were observed. Sharply de- 

 fined pressure facets are noted on most of the grains, 

 many more than in G. cardinalis, since the number of 

 separated grains are much more numerous. The surface 

 of the grains is regular, unless pressure facets may be 

 regarded irregularities; no rounded elevations or reticu- 

 lar markings were observed. The conspicuous forms of 

 the rare aggregates, as well as the numerous separated 

 and the few isolated grains, are the same as in G. car- 

 dinalis. In addition, an aggregate consisting of one large 

 and one or more small components is found as in G. 

 cardinalis, but no components in linear arrangement were 

 observed as appeared to be rarely present in G. cardinalis. 

 The grains like those of G. cardinalis are not flattened. 



The hilum, as a rule, is not distinct, much less so 

 than in G. cardinalis, but when observed is a round, oval, 

 or lenticular, non-refractive spot. Multiple hila are not 

 observed. Sometimes either a rounded or an irregular 

 cavity is found at the hilum, often larger and more irreg- 

 ular than in G. cardinalis. A short transverse cleft or 

 clefts, usually arranged in T, Y, and stellate figures, are 

 sometimes found at the hilum. Fissures frequently pro- 

 ceed from the hilum which pass obliquely towards the 

 distal corners of the grain. The fissures at and proceed- 

 ing from the hilum are present in more grains than in 

 G. cardinalis. The hilum is either centric, or has a range 

 of eccentricity from 0.45 to 0.25, commonly about 0.35, 

 of the longitudinal axis. 



The lamella; are usually not demonstrable and not so 

 distinct as in G. cardinalis. When observed they have 

 the same structure as noted for G. cardinalis. They 

 can more often be counted on the round isolated grains; 

 the number on the larger grains is 8 to 10, less numerous 

 than in G. cardinalis. 



The size of the grains varies from the smaller isolated 

 ones, which are 3 by 2/x, to the larger permanent isolated, 

 which are about 22 by 22/*, and the larger separated dome- 

 shaped components (no large aggregates found), which 

 are 24 by 24/t, in length and breadth. The common size 

 of the permanent isolated grains is about 18 by 16/t, and 

 the separated dome-shaped component is about 18 by 18/*. 

 The sizes are, on the whole, less than in G. cardinalis. 



Polariscopic Properties. 



The figure varies from centric to quite eccentric, 

 with more of the former, the mean is slightly more 

 eccentric than in G. cardinalis; it is not distinct in some 

 of the grains, and less clean-cut and distinct than in G. 

 cardinalis. The lines vary from fine to coarse, the mean 

 being coarser than in G. cardinalis, but they intersect 

 as in that species. They are usually straight, not being 

 bent nor bisected as often as in G. cardinalis. Pare 

 double and multiple figures are observed, but they are 

 not nearly so numerous as in G. cardinalis. 



The degree of polarization is moderate to high (value 

 65), lower than in G. cardinalis. There is somewhat 

 more variation in the different grains, and much greater 

 in the same aspect of a given grain, than in G. cardinalis. 



With selcnite the quadrants are moderately well de- 

 fined, but not so clean-cut as in G. cardinalis. They are 

 often slightly irregular in shape and unequal in size, in 

 somewhat more grains than in G. cardinalis. The colors 

 are pure in the majority of grains, but often show im- 



