442 



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



6. STARCHES OF H^MANTHUS KATHERINJE, H. PUNI- 



CEUS, AND H. KONIG ALBERT. 



H. katherince is described on pages 429 to 433. 



H^MANTHUS PUNICEUS (POLLEN PARENT). 



(Plate 4, fig. 20; Charts D 106 to D 126.) 



HISTOLOOIC PBOPEBTIES. 



In form the majority of the grains are simple and 

 isolated ; many occur in aggregates of from 2 to at least 

 20 components, more frequently 9. Pressure facets are 

 present in many grains. Compound grains are quite 

 numerous, the number of components varying from 2 

 to at least 26, more often the former. The grains are 

 very irregular and vary much in shape; only rarely are 

 grains with perfectly regular outlines observed. The 

 irregularities are chiefly due to the following causes: 

 First, well-marked depressions, sometimes slightly con- 

 cave on the surface which are not noticeable in H. kath- 

 erince; second, to rounded protuberances, not so fre- 

 quently observed in H . leathering, located usually near 

 the proximal end ; third, to a slight shifting of the longi- 

 tudinal axis of primary lamellae as in H. katherince; 

 fourth, to an occasional secondary set of lamellae, less 

 often observed than in H. katherince. The arrangement 

 of the components of the aggregates is very characteris- 

 tic. They may be compactly clustered and have the form 

 of simple grains, but frequently they are linearly 

 arranged to be club-shaped. When the latter, the grains 

 gradually enlarge at one end, or are root-shaped when 

 branched, or are occasionally serpentine, etc. The con- 

 spicuous forms among the isolated grains are irregular, 

 broadened ovoid ; irregular pyrif orm ; nearly round ; 

 imperfect ellipsoidal; bean-shaped; and plano-convex. 

 There are in addition imperfect quadrangular with 

 rounded angles, potato-shaped; heart-shaped; reniform; 

 napiform; and some of indefinite forms. The grains 

 are usually much flattened ; and they are more flattened 

 than those of H. katherince. 



The hilum is not usually distinct in the large grains. 

 When observed it is a round or flattened-elliptical, or 

 lenticular, non-refractive spot, which varies from centric 

 to 0.30 eccentric of the longitudinal axis, more often 

 0.40 to 0.45. The hilum in the small components of 

 aggregates is a small, round, refractive spot which varies 

 in position from centric to slightly eccentric. The hilum 

 is more often demonstrable, and, on the whole, less 

 eccentric than in //. katherince. 



The lamellce are not usually demonstrable throughout 

 the entire grain. When observed directly around the 

 hilum they form either circular or elliptical rings; but 

 most of the lamellae follow the outline of the grain. The 

 lamellae vary from fairly fine on the narrower grains to 

 very delicate on the broadened ones, and frequently one 

 coarse and more refractive lamella is located at about 

 0.33 of the distance from the hilum. On the large grains 

 20 to 28 lamella have been counted, and on the medium- 

 sized grains 8 to 11. 



The size varies from the smaller grains which are 

 4 by 3/i, to the larger which are 44 by 28^, in length and 

 breadth. The common size is 32 by 28ft.. The grains 

 tend to be broader in proportion to length than in //. 

 katherince. 



POLARISCOPIC PROPERTIES. 



The figure is centric to quite eccentric and fairly 

 clean-cut and distinct, the lines are more distinct through- 

 out entire figure in a larger number of grains than in 

 II. katherince. The lines vary from rather narrow to 

 very broad, and in the majority of the grains intersect 

 obliquely; they are more often broad and intersect at 

 right angles in more grains than in H. katherince. They 

 may also be arranged in the form of a mesial line with 

 bisected ends, as in the bean-type. The figure is often 

 quite irregular because of the lines being frequently bent 

 or bisected, the former about the same, but the latter 

 more often, than in II. katherince. Double figures (in 

 both compound and aggregates) are often present, much 

 more frequently observed than in H. katherincv. 



The degree of polarization is high to very high (value 

 78), slightly higher than in H. katherince. It varies 

 from moderate to very high with the majority moderately 

 high, there is also a variation in the same aspect of a 

 given grain. The variation in the different grains is 

 about the same, but rather more in the same aspect of a 

 given grain than in //. katherince. 



With selenite the quadrants are moderately well de- 

 fined in a majority of grains, rather less than in H . kath- 

 erince; and they are often unequal in size and irregular 

 in shape, but rather less than in H. katherince. The 

 colors may be pure, but sometimes the blue and usually 

 the yellow are not quite pure. The colors tend more 

 often to be impure than in H. katherince. 

 IODINE REACTIONS. 



With 0.25 Lugol's solution the grains color a mod- 

 erate to light violet with a reddish tint (value 40) 

 that gradually becomes quite deep tending to a blue- 

 violet, a few taking on a deeper color than the others. 

 The color is lighter but rather redder than in //. kath- 

 erince. With 0.125 Lugol's solution, the grains color 

 a light violet with reddish tint which very gradually 

 becomes slightly deeper, not so deep but redder than 

 H. katherince. After heating in water until the grains 

 are gelatinized and then adding a 2 per cent Lugol's 

 solution, the gelatinized grains color a bright rather light 

 blue, some grains deeper than others, a little deeper and 

 without the reddish tint sometimes found in H. kath- 

 erince; the solution colors a deep indigo-blue, about the 

 same as in H. katherince. If the gelatinized preparation 

 is boiled for 2 minutes and then treated with an excess 

 of iodine, the grain-residues color a light to deep dull 

 blue, many with a reddish tint, more varied but not so 

 reddish as in //. katherince; and the capsules color an 

 old-rose to deep heliotrope, the latter not quite so reddish 

 as in H. katherince. 



ANILINE REACTIONS. 



With gentian violet the grains begin to color at once, 

 and in half an hour they are moderately deep to deep, 

 slightly deeper than in //. katherince (value 62). 



With safranin the grains begin to stain immediately, 

 and in half an hour they are moderately deep to deep, a 

 little deeper than in H. katherince (value 62). 

 TEMPERATURE REACTIONS. 



The majority of the grains are gelatinized at 77 

 to 70 C., and all at 81 to 82.5 C., mean 81.75 C. The 

 smaller more slender grains, which are not very numer- 

 ous, are the most resistant. 



