GENUS MU8CARI. 



579 



grain becomes marked by fine strise, which radiate in all directions from the hilum. The less resis- 

 tant starch is gelatinized, while the more resistant forms a thick, finely striated, dense band at the 

 margin, which slowly becomes thinner, less dense, and clearer as the grain swells, until it is a thin, 

 transparent capsule. The completely swollen grains are large and do not retain much of their orig- 

 inal form, and the capsules are folded, crumpled, and wrinkled. 



Reaction with ferric chloride begins in a few grains in a minute. About throe-fourths are com- 

 pletely gelatinized in 11 minutes, nearly all in 27 minutes, and all in 40 minutes. The reaction 

 begins at the distal end, which is internally fissured at one or two points, from which fissures gelatin- 

 ized starch protrudes, forcing out the capsule. The fissures widen as more starch becomes gelatin- 

 ized, and then the starch at the margin of this end is gelatinized. The reaction then spreads 

 upward and inward, and often when it has extended about half of the distance between the hilum 

 and the distal end the hilum swells rapidly, together with the proximal end, into a large, smooth 

 projection. The small central portion of the grain that has remained ungelatinized is completely 

 surrounded by gelatinized starch, but also becomes gelatinized. The capsules are very large, 

 distorted, and wrinkled, and do not retain much of the original form of the grain. 



With Purdy's solution the reaction begins in some grains in 30 seconds and in most grains in 2 

 minutes. About two-thirds of the grains are partially gelatinized in 8 minutes, and three-fourths 

 in 20 minutes. The reaction appears to be the same qualitatively as that with pyrogallic acid. 



STARCH OF MUSCARI PARADOXUM. (Plate 42, figs. 251 and 252. Chart 164.) 



Histological Characteristics. — In form the grains are usually simple and for the most part iso- 

 lated. There are a few compound grains and a number of small aggregates, consisting generally 

 of one large grain with one or more small, adherent grains, one of which is frequently very minute. 

 One or more pressure facets are occasionally found on the isolated grains. The outline of the grains 

 is commonly irregular. The conspicuous forms are round, 

 oval to ovoid, with transition forms to clam-shell-shaped 

 grains; when viewed on edge they are flattened ellipses, 

 or lenticular, or somewhat wedge-shaped. These grains 

 vary more in outline, the hilum is usually fissured, and 

 there is a greater tendency to the oval type than in M. 

 botryoides. 



The hilum is a round or oval spot, centric on the 

 round grains, and eccentric two-fifths to one-third of the 

 longitudinal axis in the other forms; sometimes two or 

 more hila occur in a single grain. The hilum is usually 

 fissured; one transverse, one longitudinal, or two or more 

 fissures may intersect each other, often forming a cross, 

 but sometimes the arrangement is stellate or irregular. 

 The fissures may be straight, curved, or ragged; they 

 may appear without connection with the hila. 



The lamellce are rather distinct, coarse, complete 

 rings or ellipses when located near the hilum. About 

 three-fourths the distance from the hilum there is com- 

 monly a very distinct, coarse lamella. Those near the 

 distal end are finer and less distinct, and probably discontinuous in the forms approaching the 

 mussel-shell shape. Those near the distal end and margin take the form of the grain; they are also 

 more irregular here than near the hilum. There are 6 to 10 lamellse on a single grain. 



The grains vary in size from 6 to 43^. The common size is 24 by 29^ in length and breadth. 



Polariscopic Properties. — The figure is either centric or slightly eccentric, usually distinct, 

 but not clear-cut. The lines are generally straight and rather thick, becoming somewhat thicker 

 towards the margin. They are occasionally bisected or slightly bent in the larger irregular forms. 



The degree of polarization is high. It varies in the largo grains from quite high to rather low, 

 in the smallest grains being usually rather low. It varies in different parts of the same aspect 

 of a given grain. 



With selenite the quadrants in the smallest grains, and in some of the large, are fairly well 

 defined, quite regular in shape, and equal in size. In other grains, especially the largest ones, thej' 



Curve of Reaction-Intensities of Starch of Muscari 

 paradoxum. 



