572 



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



sules as in N. empress. In this reaction N. madame de 

 graaff shows qualitatively a closer relationship to N. 

 albicans than to N. empress. 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in about 2 per cent of the 

 entire number of grains and 10 per cent of the total 

 starch in 5 minutes ; in about 6 per cent of the grains and 

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

 12 per cent of the grains and 49 per cent of the total 

 starch in 30 minutes ; in about 29 per cent of the grains 

 and 58 per cent of the total starch in 45 minutes ; and in 

 about 32 per cent of the grains and 65 per cent of the 

 total starch in 60 minutes. (Chart D 321.) 



The hilum and lamellae are as distinct as in 2V. albi- 

 cans. Gelatinization begins at the hilum, as in the 

 parents, and proceeds according to the two methods noted 

 under N. empress. The great majority of the grains 

 follow closely the first type as described under N. em- 

 press, except that 2 fissures do not so frequently extend 

 from the line dividing the primary from the secondary 

 starch, and the primary material is not divided into such 

 fine particles. A small number are gelatinized accord- 

 ing to the second method described, but more swelling 

 occurs and less distinct granulation. The gelatinized 

 grains are usually as swollen and have as thick capsules 

 as in N. empress, but some are as in N. albicans. 



In this reaction N. madame de graaff shows qualita- 

 tively a closer relationship to A 7 , empress than to IV. 

 albicans. 



The reaction with sulphuric acid begins immedi- 

 ately. Complete gelatinization occurs in about 86 per 

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

 the total starch in 2 minutes; and in about 97 per cent 

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

 starch in 5 minutes. (Chart D 322.) 



The hilum becomes distinct, attended by the forma- 

 tion of a small bubble in a smaller number of grains than 

 in either parent. The lamellae are as distinct as in both 

 parents. Gelatinization begins at the hilum and pro- 

 gresses according to the two methods described in IV. 

 empress. The first method, which is seen in a great 

 majority of the grains, is the same as that described for a 

 majority of the grains of IV. empress, and resembles that 

 described for all the grains of IV. albicans. In the second 

 type, which is seen in a rather small minority of the 

 grains, the differences noted are that the concentric fis- 

 sures that divide the portion distal to the hilum are regu- 

 lar and follow the lines of the lamellae, and the material 

 at the proximal end is distinctly striated and the striae 

 remain distinct for some time during the gelatinization 

 of the grain. In this reaction IV. madame de graaff 

 shows qualitatively a closer relationship to IV. empress 

 than to IV. albicans. 



21. STARCHES OF NARCISSUS WEARDALE PERFECTION, 



N. MADAME DE GRAAFF, AND N. PYRAMUS. 

 Starch of IV. madame de graaff (pollen parent) is 

 described on pages 570 to 572. 



NARCISSUS WEARDALE PERFECTION (SEED PARENT). 



(Plate 13, fig. 76; Charts D 323 to D 328.) 

 In form the grains are usually simple and isolated, 

 but there is a moderate number of both compound grains 

 and aggregates. The compound grains belong to two 



types, of which the first, which consists of 2 moderate- 

 sized grains adherent and surrounded by 1 or 2 common 

 secondary lamellae, is much more often seen than the 

 second, which consists of a number of hila in an amor- 

 phous-appearing mass of starch that is surrounded by 

 1 or 2 secondary lamellae. The aggregates are always 

 doublets of small or common-sized grains. A small ma- 

 jority of the simple grains shows clearly a primary grain 

 which has been inclosed by 4 or 5 secondary lamellae. The 

 grains are usually regular, but sometimes irregular, and 

 any irregularities which occur are due to the following 

 causes: (1) Small, irregular elevations and depressions 

 in the surfaces and margins of the grains; (2) 1 or 2 

 small rounded or large rounded or pointed protuberances 

 from either end or side; (3) a greater development of 

 one part of the distal end or of one side. The con- 

 spicuous forms are ovoid, plano-convex, triangular with 

 rounded angles, and nearly round. The additional forms 

 are elliptical, irregularly quadrilateral, and rarely pyri- 

 form. The broader forms are somewhat flattened, the 

 others are not. 



The hilum, when not fissured, is a small round or, 

 rarely, lenticular spot which is not very distinct. It is 

 fissured in the great majority of the grains and the 

 fissures have the following forms: (1) A straight, trans- 

 verse, or, rarely, oblique or longitudinal, line; (2) 

 V-shaped; (3) T-, -Y, or cruciate-shaped; (4) a flying- 

 bird form. The hilum is sometimes centric, but in the 

 majority of the grains it is eccentric from 0.45 to 0.29, 

 usually 0.35, of the longitudinal axis. 



The lamella in most of the grains are not very dis- 

 tinct, and in a moderate number are not visible in every 

 part of the grain. They are usually more distinct near 

 the hilum than near the margin. They are rather coarse 

 continuous rings which have in general the form of the 

 outline of the grain, but which follow it closely only near 

 the margin. The number counted on some of the larger 

 grains varies from 8 to 12, usually 10. 



In size the grains vary from the smaller which are 

 3 by 3/n., to the larger which are 30 by 40/t and 40 by 36/x, 

 in length and breadth. The common sizes are 18 by 20/t, 

 22 by 22/i, and 24 by 20/u. 



Comparison of the histologic properties between IV. 

 madame de graaff and IV. weardale perfection shows: 



There are fewer compound grains and aggregates. 

 The compound grains belong to the two types de- 

 scribed under IV. weardale perfection, but in the 

 first type, which is the one most commonly seen, 

 there may be 3, 4, or 5 components instead of but 2. 

 There is a rather larger majority of the grains in which 

 both a primary and a secondary formation of starch can 

 be seen. The grains are rather more irregular in form 

 and the irregularities are due to: (1) Elevations and 

 depressions in the margin and top surface; (2) pressure 

 facets at the distal end and sides; (3) protuberances 

 from either end or sides. The grains are somewhat more 

 varied in form. 



The hilum is not so often fissured and the fissures 

 are not so deep nor so extensive, but have the same 

 forms. It is somewhat less eccentric, the usual degree 

 of eccentricity being 0.37 of the longitudinal axis. 



The lamella are somewhat less distinct and are not 

 so coarse. 



