440 



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



9 per cent of the total starch in 5 minutes ; in about 35 

 per cent of the grains and 50 per cent of the total starch 

 in 15 minutes; in about 67 per cent of the grains and 81 

 per cent of the total starch in 30 minutes; in about 73 

 per cent of the grains and 93 per cent of the total starch 

 in 45 minutes ; and in about 90 per cent of the grains and 

 98 per cent of the total starch in 60 minutes. The un- 

 gelatinized portion of the grains consists of a part of the 

 outline of a few grains, together with rare grains that are 

 unaffected. ( Chart D 89.) 



The reaction with hydrochloric acid begins at once. 

 Complete gelatinization occurs in less than 3 per cent 

 of the entire number of grains and 3 per cent of the total 

 starch in 5 minutes; in about the same in 15 minutes; 

 in about 9 per cent of the grains and 11 per cent of the 

 total starch in 30 minutes; in about 26 per cent of the 

 grains and 30 per cent of the total starch in 45 minutes ; 

 and in about 28 per cent of the grains and -42 per cent of 

 the total starch in 60 minutes. The ungelatinized starch 

 is in the form of many entire grains and parts of the 

 margins of others. (Chart D 90.) 



The reaction with potassium hydroxide begins in a 

 few grains immediately. 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 2 

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

 15 minutes; in about 3 per cent of the grains and 7 per 

 cent of the total starch in 30 minutes ; in about 5 per cent 

 of the grains and 9 per cent of the total starch in 45 

 minutes; and in about 7 per cent of the grains and 11 

 per cent of the total starch in 60 minutes. (Chart D 91.) 



The reaction with potassium iodide begins slowly. 

 Complete gelatinization occurs in only rare grains and 

 in less than 1 per cent of the total starch in 5 minutes ; 

 less than 1 per cent of the grains and over 1 per cent of 

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

 the grains and 2.5 per cent of the total starch in 30 

 minutes; in about the same percentage in 45 minutes; 

 and in about the same percentage of grains and 3 per cent 

 of the total starch in 60 minutes. (Chart D 92.) 



The hiluni and fissures react about the same as in 

 H. katherince, the hilum swells less and enlargement of 

 fissures is less frequent than in H. magnificus. The en- 

 tire grain becomes very refractive and in most of the 

 grains the definition of lamellae and the refractive border 

 is about the same as in H. katherince, but occasionally 

 grains are found with one very prominent lamella form- 

 ing a line of demarcation between the main body of the 

 grain and the refractive border, which is so often found 

 in H. magnificus. The fissures are usually delicate and 

 much more like those of H. katherince, but in a few grains 

 they are quite deep and much like those of H. magnificus. 

 The course of gelatinization is even more varied than 

 in both parents, while it more frequently starts as in 

 H. katherince, yet in some grains the marginal border 

 and main body of the grain react as noted in H. mag- 

 nificus. The starch is sometimes disorganized with the 

 appearance of refractive granules, more frequently than 

 in II. kat'hcrince but much less frequently than in H. 

 magnificus. The starch may be broken into refractive 

 masses previous to gelatinization, as noted in H. katii- 

 erincv, but not observed in II. magnificus. The most 



resistant starch is more frequently located as described 

 in H. katherince, though in a small number of grains it 

 may occur as in H. magnificus. 



The gelatinized grains are swollen and slightly to 

 considerably distorted, about the same as in H. katherince 

 but less than in H. magnificus. Some grains are only 

 partially gelatinized, while many are but little affected 

 beyond the swelling of the hilum and the enlargement of 

 the fissures, much closer in this respect to //. katherince 

 than to H. magnificus. Excepting in a few grains, H. 

 andromeda exhibits qualitatively a much closer relation- 

 ship to H. katherince than to H. magnificus. 



The reaction with potassium sulphocyanate begins in 

 very few grains in 1 minute. Complete gelatinization 

 occurs in less than 1 per cent of the entire number of 

 grains and of the total starch in 5 minutes; in about 2 

 per cent of the grains and 3 per cent of the total starch 

 in 15 minutes; in about the same percentage of grains 

 and 3.5 per cent of the total starch in 30 minutes; in 

 about the same percentage of grains and 4 per cent of the 

 total starch in 45 minutes; and in about 3.5 per cent 

 of the grains and 4 per cent of the total starch in 60 

 minutes. ( Chart D 93.) 



The swelling of the hilum and the absence of a bubble 

 are about the same as noted for both parents A delicate 

 fissure, sometimes present in the untreated grain, often 

 becomes a little deeper than in H. katherince, but much 

 less enlarged and refractive than in H. magnificus. 

 The lamella occasionally become more distinct, a little 

 more frequently than in H. kaiherince, but with much 

 less frequency than in //. magnificus. The methods of 

 gelatinization described for both parents are observed, but 

 many more grains follow those noted in //. kath.erince 

 than in H. magnificus. The fissures more closely re- 

 semble those of H. katherince than of II. magnificus. The 

 mesial region is more frequently disorganized with irregu- 

 larly massed granules of somewhat greater refractivity 

 than in H. katherince, but not so brilliant in so many 

 grains as was found in H. magnificus. The fissures occa- 

 sionally become very deep and sparingly branched, fol- 

 lowed by the breaking of the starch into moderately large 

 refractive fragments, not quite so frequently observed 

 as in H. katherinw, but with greater frequency than in 

 //. magnificus. 



The gelatinized grains are swollen and slightly to 

 considerably distorted, greater distortion in a few more 

 grains than in //. kaiherince, but in considerably less 

 than //. magnificus. Many grains in which the reaction 

 is almost complete contain a number of refractive gran- 

 ules, these are more frequently arranged in the same 

 manner and located similarly to those observed in H. 

 katherince, but a small number more closely follow the 

 arrangement and location of those in H. magnificus. 

 Excepting in a few grains, //. andromeda shows a much 

 closer relationship to H. katherince than to H. magnificus. 

 The reaction with potassium sulphide begins in only 

 rare grains in 1 minute. Complete gelatinization occurs 

 in less than 1 per cent of the entire number of grains and 

 of the total starch in 5 minutes ; in about the same per- 

 centage of each in 15, 30, 45, and 60 minutes, respec- 

 tively. (Chart D 94.) (Insufficient material to study 

 the qualitative reactions.) 



