640 



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



The reaction with calcium nitrate begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 

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



9 per cent of the grains and 30 per cent of the total 

 starch in 15 minutes; in about 21 per cent of the 

 grains and 45 per cent of the total starch in 30 min- 

 utes; in about 24 per cent of the grains and 54 per 

 cent of the total starch in 45 minutes; in about 27 

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

 in 60 minutes. (Chart D 392.) 



The reaction with uranium nitrate begins in a few 

 grains in 30 seconds. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 



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

 5 per cent of the grains and 20 per cent of the total starch 

 in 15 minutes; in about 6 per cent of the grains and 22 

 per cent of the total starch in 30 minutes ; in about 11 

 per cent of the grains and 25 per cent of the total starch 

 in 45 minutes; in about 15 per cent of the grains and 29 

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

 D393.) 



The reaction with strontium nitrate begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 12 

 per cent of the total starch in 5 minutes; in about 21 

 per cent of the grains and 48 per cent of the total starch 

 in 15 minutes; in about 44 per cent of the grains and 

 67 per cent of the total starch in 30 minutes; in about 52 

 per cent of the grains and 78 per cent of the total starch 

 in 45 minutes; in about the same percentage of the 

 grains and 80 per cent of the total starch in 60 minutes. 

 (Chart D394.) 



The reaction with cobalt nitrate 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 2 per 

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

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

 15 minutes ; in about 1 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 2 per cent of the grains 

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

 D 395.) 



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 12 

 per cent of the total starch in 5 minutes ; in about 2 per 

 cent of the grains and 19 per cent of the total starch in 

 15 minutes; in about 14 per cent of the grains and 50 

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

 19 per cent of the grains and 54 per cent of the total 

 starch in 45 minutes; in about 29 per cent of the 

 grains and 61 per cent of the total starch in 60 minutes. 

 (Chart D 396.) 



The reaction with cupric chloride begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 

 10 per cent of the total starch in 5 minutes; in about 16 

 per cent of the grains and 42 per cent of the total starch 

 in 15 minutes; in about 26 per cent of the grains and 

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

 29 per cent of the grains and 64 per cent of the total 



starch in 45 minutes; in about 31 per cent of the grains 

 and 70 per cent of the total starch in 60 minutes. ( Chart 

 D397.) 



The reaction with barium 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 



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

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

 15 minutes; in about 2 per cent of the grains and 9 per 

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

 same percentage of the grains and 10 per cent of the 

 total starch in 45 minutes; in about 3 per cent of the 

 grains and 11 per cent of the total starch in 60 minutes. 

 (Chart D398.) 



The reaction with mercuric chloride begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 about 1 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 11 per cent of the total starch in 

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

 cent of the total starch in 30 minutes; in about 7 per 

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

 minutes ; in about 7 per cent of the grains and 25 per cent 

 of the total starch in 60 minutes. (Chart D 399.) 



Iris trojana (Pollen Parent). 



(Plate 18, fig. 104, Charts D 379 to D 399.) 

 Histologic Properties. 

 In form the grains, as in /. iberica, are usually simple 

 and isolated, and there are even fewer aggregates of 2, 3, 

 or more components than in I. iberica. There are, how- 

 ever, many more compound grains than in this species 

 and these are of several types. The first type consists of 



2 grains, each consisting of a hilum and 4 or 5 lamellae 

 adherent and held together, except for 1 or 2 outer 

 lamellae, which encircle the margin only on 1 side, by 9 to 

 10 secondary lamellae, and so constitute a double proxi- 

 mal end to a large, elongated grain. The grains of the 

 second type are simply irregular masses of homogeneous- 

 appearing grains, whose hila alone show that separate 

 grains are present, the whole bound together by one thick 

 layer of starch. The third type consists of 2 grains, each 

 consisting of a hilum and 3 or 4 lamellaa held together by 

 1 or 2 common secondary lamellae. The grains are more 

 irregular in form than /. iberica and the irregularities 

 are due to the following causes in the order of the 

 frequency of their occurrence: (1) Deep triangular or 

 cone-shaped notches in the distal margin, these occurring 

 in nearly every grain; (2) a secondary set of lamellas, 

 whose longitudinal axis is at an angle (usually a right 

 angle) with that of the primary grain; (3) deviation of 

 the axis of a grain with consequent bending of the grain, 

 usually in the middle, but sometimes at the distal end ; 

 (4) shallow depressions and elevations of the surface, 

 producing a somewhat wavy or undulating outline; (5) 

 an occasional small pointed, or large rounded and irregu- 

 lar, protuberance from either end or from the sides. 

 The conspicuous forms are elongated elliptical, in which 

 the flattening of the distal end is more common than in 

 I. iberica, and boot-shaped. The additional forms are 

 shortened and regular T shape, pyriform, napiform, 

 club-shaped, ovoid with flattened distal end, round and 

 nearly round, and triangular. The grains as in I. iberica 

 are not flattened. 



