728 



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



begins first at the distal and then at the proximal end, 

 but the progress of gelatinization is the same as that 

 described. The gelatinized grains are much swollen, have 

 rather thin capsules, and are very much distorted, retain- 

 ing none of the form of the untreated grain. 



The reaction with calcium nitrate begins immediately. 

 Complete gelatinization occurs in about 81 per cent of the 

 entire number of grains and 95 per cent of the total starch 

 in 1 minute ; in more than 99 per cent of the grains and 

 total starch in 5 minutes. (Chart D 566.) 



The reaction with uranium nitrate begins in 15 sec- 

 onds. Complete gelatinization occurs in about 66 per 

 cent of the entire number of grains and 84 per cent of the 

 total starch in 1 minute; in about 97 per cent of the 

 grains and in more than 99 per cent of the total starch in 

 3 minutes ; in more than 99 per cent of the grains and 

 total starch in 5 minutes. (Chart D 567.) 



The reaction with strontium nitrate begins imme- 

 diately. Complete gelatinization occurs in about 90 per 

 cent of the entire number of grains and 95 per cent of 

 the total starch in 1 minute; in more than 99 per cent 

 of the total starch in 3 minutes. (Chart D 568.) 



The reaction with cobalt nitrate begins in 30 seconds. 

 Complete gelatinization occurs in about 85 per cent of the 

 entire number of grains and 98 per cent of the total starch 

 in 5 minutes; in about 96 per cent of the grains and in 

 more than 99 per cent of the total starch in 15 minutes. 

 (Chart D 569.) 



The hilum becomes distinct, unaccompanied by the 

 formation of a bubble. The lamella? also become distinct. 

 Gelatinization begins at the hilum and progresses accord- 

 ing to two methods. In the first, which is seen in all the 

 broader grains which are in the majority, 2 furrows are 

 observed to extend transversely or slightly obliquely from 

 the hilum on either side to the margin. That part of 

 the grain which is distal to these furrows and to the hilum 

 becomes more refractive in appearance, accompanied by 

 a greater distinctness of the lamella?, and is then divided 

 by very fine fissures radiating from the hilum. Mean- 

 while that part of the grain proximal to the hilum and 

 the furrows becomes homogeneous-looking and very re- 

 fractive. The hilum now begins to enlarge steadily, appa- 

 rently more toward the proximal than toward the distal 

 end, and the proximal starch and that of the sides nearby 

 forms a thick, homogeneous-looking band at the proximal 

 margin which just at the apex is thinner and more hya- 

 line in appearance than elsewhere. The distal starch 

 forms a broad granular mass at the distal end. That 

 portion just at the margin, however, is not granular and 

 is homogeneous-looking. This latter portion is the first 

 to be completely gelatinized, then the band at the proxi- 

 mal end and sides nearby, and finally the granular mass 

 near the distal margin. In the second method, which is 

 seen in the elongated grains, the hilum enlarges some- 

 what and 2 furrows or fissures are seen to extend obliquely 

 from either side of the hilum nearly to or quite to the 

 distal margin. The starch comprehended between these 

 2 furrows grows more refractive and is then divided into 

 filaments or bundles of filaments from the hilum nearly to 

 the margin by 2 rows of fissures, slanting proximally 

 from the original furrows or fissures, to the longitudinal 

 axis of the grain. These filaments are partially gela- 

 tinized and leave a granular residue which collects just 

 above the starch at the distal end. This starch at the 



distal end is rather indistinctly fissured by parallel longi- 

 tudinal fissures and is then gelatinized, becoming slowly 

 thinner and more hyaline in the process. The starch at 

 the proximal end and sides meanwhile forms a thick, 

 homogeneous-looking, marginal band, and as the hilum 

 swells and enlarges in the direction of the proximal end 

 more than toward the distal end, the starch at the proxi- 

 mal apex becomes thinner and more hyaline in appear- 

 ance. The starch at the distal margin gelatinizes first, 

 then that at the proximal margin and sides, and finally 

 that composing the granular mass near the distal end. 

 The gelatinized grains are much swollen, have rather 

 thin capsules, and are considerably distorted, especially 

 at the distal end. They, however, retain some resem- 

 blance to the form of the untreated grain. 



The reaction with copper nitrate begins immediately. 

 Complete gelatinization occurs in about 78 per cent of 

 the entire number of grains and 86 per cent of the total 

 starch in 30 seconds ; in about 92 per cent of the grains 

 and in more than 99 per cent of the total starch in 1 

 minute. (Chart D 570.) 



The reaction with cupric chloride begins immediately. 

 Complete gelatinization occurs in about 67 per cent of the 

 entire number of grains and 87 per cent of the total starch 

 in 1 minute; in about 96 per cent of the grains and' in 

 more than 99 per cent of the total starch in 3 minutes ; 

 in more than 99 per cent of the grains and total starch 

 in 5 minutes. (Chart D 571.) 



The reaction with barkan chloride begins in 15 sec- 

 onds. Complete gelatinization occurs in about 60 per 

 cent of the entire number of grains and 74 per cent of the 

 total starch in 5 minutes ; in about 78 per cent of the 

 grains and 95 per cent of the total starch in 15 minutes; 

 in about 91 per cent of the grains and 98 per cent of the 

 total starch in 30 minutes; very little if any further 

 advance in 45 and 60 minutes. (Chart D 572.) 



The reaction with mercuric chloride begins imme- 

 diately. Complete gelatinization occurs in about 57 per 

 cent of the entire number of grains and 68 per cent of 

 the total starch in 1 minute; in 86 per cent of the grains 

 and 97 per cent of the total starch in 3 minutes; in 

 about 95 per cent of the grains and in more than 99 per 

 cent of the total starch in 5 minutes. (Chart D 573.) 



Musa Gilletii (Pollen Parent). 



(Plate 23, fig. 134; Charts D 553 to D 573.) 

 Histologic Properties. 

 In form the grains are usually simple and isolated, 

 there being a few compound grains and a few aggregates. 

 The compound grains belong to two types instead of 

 but one as in M. arnoldiana: (1) 2 small or common- 

 sized grains surrounded by 2 or 3 common sec- 

 ondary lamella}; (2) 3 or more very small grains sur- 

 rounded by 20 or 30 common secondary lamellae. The 

 aggregates, of which none was seen in N. arnoldiana, 

 each consists of 2 grains of equal size adherent at their 

 distal ends or at the distal end of one and the side of the 

 other, or of 3 or more equal-sized grains arranged in an 

 irregularly linear manner. The grains are, as in M. 

 arnoldiana, moderately regular in form, and any irregu- 

 larities are due to the following causes: (1) A deviation 

 of the longitudinal axis (usually near the distal end) 

 and a consequent bending of the grain ; (2) small nipple- 

 like or larger pointed projections from the proximal end ; 



