560 



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



of the secondary deposit is not so coarse and the laniel- 

 lation more distinct and persistent, which shows the in- 

 fluence of N. poeticus poetarum. A moderate-sized 

 minority of the grains follows the second method, the 

 differences noted being that the striae at the proximal 

 end are not so coarse and the lamellation more distinct 

 and more persistent. The gelatinized grains are as much 

 swollen, have as thin capsules, and are as much distorted 

 as in N. abscissus. 



In this reaction N. will scarlet shows qualitatively 

 a closer relationship to N. abscissus than to N. poeticus 

 poetarum. 



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 92 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 310.) 



The hilum and lamellae are as distinct as in N. 

 abscissus and a bubble is formed at the hilum as fre- 

 quently as in that starch. Gelatinization begins at the 

 hilum and progresses according to the two methods seen 

 in both parents, and the majority of the grains follow 

 the same method that was described for the majority of 

 the grains of N. abscissus, and for only a minority of the 

 grains of N. poeticus poetarum, while a small minority 

 follows the second method. The Only difference noted 

 in either method was that there was not so much fissuring 

 of the grains. The gelatinized grains are as much 

 swollen, have as thick capsules, and are as distorted 

 as in N. abscissus. 



In this reaction N. will scarlet shows qualitatively a 

 somewhat closer relationship to N. abscissus than to 

 N. poeticus poetarum. 



19. STARCHES OF NABCISSUS ALBICANS, N. ABSCIS- 

 SUS., AND N. BICOLOB APKICOT. 



Starch of N. abscissus is described on pages 554 

 to 558. 



N. ALBICANS (SEED PARENT). 



(Plates 12 and 13, figa. 70 and 74; Charts D 311 to D 316.) 

 HISTOLOGIC PKOPERTIES. 



In form the grains are usually simple and isolated, 

 although aggregates and compound grains are of very 

 common occurrence. The aggregates are usually doub- 

 lets or triplets of equal size, linearly or pyramidally 

 arranged; but there are some consisting of 10 to 12 

 grains which form an irregular, compact, knobby mass. 

 The compound grains belong to three types : In one there 

 are 2 or 3 component grains, each consisting of a hilum 

 surrounded by 3 or 4 lamellae, and all the components 

 in turn surrounded by 5 or 6 secondary lamellae ; in the 

 second type there are 2 to 12 component grains, each 

 consisting of a hilum and a distinct lamella, and all sur- 

 rounded by 1 or 2 secondary lamellae ; in the third type 

 there are, as a rule, 2 or rarely 3 component grains, one 

 of which is a large simple grain, to the side of the 

 distal end of which 1 or 2 small grains have become 

 adherent, and the combination later inclosed by 1 or 2 

 secondary lamellae. A number of aggregates consists 

 of one or more simple grains combined with one or 

 more compound grains of the first and second types 

 described. The grains are, as a rule, moderately regular 

 in form, but a majority show some and a moderate num- 



ber show considerable irregularities, and these irregu- 

 larities are due to the following causes: (1) Small or, 

 rarely, large rounded protuberances from the proximal 

 end, sides, or distal end; (2) shallow depressions and 

 elevations of the surface and margin of the grain, causing 

 au undulating or wavy outline; (3) deviation of the 

 transverse axis and consequent bending of the grain in 

 the middle or at either end; (4) the greater development 

 of one part of the distal end; (5) 2 indentations, one 

 on either side of, and just below, the proximal apex. 

 There is a moderate number of grains in which a rather 

 small grain has later been surrounded by 3 or 4 lamellae 

 of a secondary starch which are distinctly separated from 

 the primary lamellae by a deep furrow, and by the differ- 

 ence in refractivity of the starches. The conspicuous 

 forms are broad, rounded ovoid, narrow pointed ovoid, 

 nearly round, and short elliptical with both ends rounded 

 or with a flattened distal end. There are also plano- 

 convex, triangular with rounded angles, quadrilateral, 

 a few pyriform, and a few lenticular forms. The broad 

 forms are flattened, but the others are not. 



The hilum, when not fissured, is a not very distinct, 

 small, round or, rarely, lenticular spot. It usually is 

 fissured, however, and the fissures have the following 

 forms: (1) A short, straight line placed transversely, 

 obliquely, or rarely, longitudinally; (2) irregularly V- 

 or Y-shaped; (3) a long, irregularly branching, trans- 

 verse line; (4) T-shaped or cruciform; (5) flying-bird 

 figure. The hilum is sometimes centric, but in the 

 majority of the grains it is eccentric from 0.46 to 0.25, 

 usually 0.38, of the longitudinal axis. 



The lamellw are commonly not very distinct, but some 

 grains show rather fine continuous rings, which usually 

 follow the form of the outline of the grain. The pri- 

 mary grains, which have a secondary deposit of starch 

 surrounding them, do not show lamellation in the pri- 

 mary starch, but do in the secondary deposit. The num- 

 ber of lamellae counted on some of the large grains varies 

 from 6 to 14, usually 10. 



The size of the grains varies from the smaller which 

 are 4 by 4/*, to the larger elongated forms which are 

 40 by 34/t, and the larger broad forms which are 28 by 

 38/* and 40 by 40/*, in length and breadth. The common 

 sizes are 22 by 26ju,, 22 by 22/x, and 22 by 18/t. 



Comparison of the histologic properties between N. 

 abscissus and N. albicans shows : 



There are not so many compound grains or aggre- 

 gates. The compound grains belong to two types, which 

 are the same as the first two types described under N. 

 albicans; the third type described under that starch 

 is not seen. The aggregates belong to the same types 

 as in N. albicans. There are more simple grains in 

 which a rather small primary grain has been surrounded 

 by several secondary layers of starch. The grains are 

 somewhat more irregular in form and the irregularities 

 are due to the same causes, but there are fewer pointed 

 protuberances and more small depressions and elevations 

 of the surface. The forms are somewhat more rounded 

 than those of N. albicans. 



The hilum is more distinct and is not so frequently 

 nor so extensively fissured, but the fissures have the same 

 forms. A cruciate figure is not so often seen, however. 

 The hilum is sometimes more eccentric, but usually the 

 degree of eccentricity is the same as in N. albicans. 



