GENUS CRINUM. 



637 



a smaller number of both compound grains and aggregates are observed; when the latter are present 

 they are of the same character as those of C. fimbriaiulum. 



The hilum is a round or lenticular clear spot, eccentric about one-third to one-fourth of the 

 longitudinal axis. It is not usually fissured, but sometimes one short fissure passes from each side 

 of the hilum, or there may be a short, transverse, crescentic fissure. 



The lamella are frequently not demonstrable near the hilum, but when observed they form 

 fine circular or oval rings; toward the distal end they follow the outline of the grain. There is 

 often one, sometimes three, refractive and coarser lamellae placed at varying distances from the 

 hilum. On the large grains frequently 24 to 26 lamellae, rarely 42, may be counted. The lamellae 

 are of the same character and arrangement as those in C. fimbriaiulum, but can be determined over 

 a greater part of many more grains than in that species. 



The grains vary in size; the smaller are 3 by 2fi; the larger are 44 by dOfi in length and breadth. 

 The common size is 24 by 14/i in length and breadth. 



Polariscopic Properties. — The figure is eccentric. Its lines intersect obliquely and are fine and 

 usually straight, with slight broadening at the margin; occasionally bent and rarely bisected. Double 

 figures are rare. The figure is much more regular than 

 in C. fimbriaiulum. 



The degree of polarization is high to very high. The 

 proportion of grains in which the polarization is very high 

 is less than in C. fimbriaiulum, so that the degree of polar- 

 ization is somewhat lower. 



With selenite the quadrants are distinct, clean-cut, 

 and unequal in size, but usually regular in shape. The 

 colors are generally pure. 



Iodine Reactions. — With 0.25 per cent Lugol's solu- 

 tion the grains color a deep blue-violet, some deeper than 

 others, the color deepening rapidly. The tint is at first 

 slightly lighter than in C. fimbriaiulum, but it deepens 

 more rapidly. With 0.125 per cent solution the grains 

 color a very light blue-violet, some deeper than others, 

 but slightly lighter than in C. fimbriaiulum, yet deepen- 

 ing rather more quickly than in C. fimbriaiulum. After 

 heating in water until all the grains are gelatinized and 

 then adding iodine, the solution colors a deep indigo-blue 

 and the grains a fairly deep bright-blue, both about the 

 same as in C. fimbriaiulum. If the grains are boiled for 2 minutes and then treated with iodine, 

 the grain-residues do not color or become a very light to a fairly deep blue and the solution a very 

 deep blue. The grain-residues are slightly lighter in color than in C. fimbriaiulum. With an 

 excess of iodine the grain-residues color a deep dull-blue, some with reddish tint, and the capsules 

 a deep old-rose to wine-red. The grain-residues and capsules are deeper in tint and the capsules 

 are redder than in C. fimbriaiulum. 



Staining Reactions. — With gentian violet the grains begin to color slightly at once and in 30 

 minutes are lightly stained. The color is slightly deeper than in C. fimbriaiulum. 



With safranin the grains begin to color slightly at once and in 30 minutes are fairly stained. 

 The tint is slightly deeper than in C. fimbriaiulum. 



Temperature Reaction. — The temperature of gelatinization is 76° to 78° C, mean 77°. 



Ejfects of Various Reagents. — With chloral hydrate-iodine the reaction begins immediately. 

 Many small grains and a few of the larger are gelatinized in 30 seconds, about half in 5 minutes, 

 about nine-tenths in 10 minutes, all but rare resistant grains in 12 minutes, in which the reaction 

 is usually complete in 20 minutes, rarely 30 minutes. The gelatinized grains are uniformly swollen 

 and resemble the shape of the untreated grain. The reaction is qualitatively the same as in C. 

 fimbriaiulum, except that a small dark area is generally found at the hilum instead of the large, 

 swollen structures containing bubbles present in that species. 



Reaction with chromic acid begins in a few grains in 45 seconds. A small number are dissolved 

 in 5 minutes, nearly all in 8 minutes, and all in 10 minutes. The reaction is qualitatively the same 

 as in C. fimbriaiulum, except that usually a small bubble or none is formed at the hilum. 



Curve of Reaction-Intensities of Starch of Crinum 

 americanum. 



