GENTJS CALATHEA. 



836 



PS CI PA CA 

 POPS 



The hilum is a distinct round spot, eccentric about one-fourth to one-fifth, usually one-fourth, 

 of the longitudinal axis. Tlie hilum frequently is fissured. The fissuration may be in the form 

 usually of a short, well-marked, transverse fissure, sometimes having a double curve. Fissures may 

 be arranged in groups to form either irregtilar stellate figures or a cross. 



The lamellae are distinct, coarse, complete rings near the hilum. They are not so coarse but are 

 more distinct near the margin and distal end. There are 2 or 3 or more highly refractive lamellse 

 in some forms at varying distances between the hilum. and within one-half to about two-thirds of 

 the length of the grain. The number may vary in the short broad to elongated from 8 to 23. 



In size the smaller grains are about S/x, and the larger oval and allied forms 46 by 28ai in length 

 and breadth. The common size is 28 by 16/* in length and breadth. 



Polarisco-pic Properties. — The figure is usually eccentric, distinct, clear-cut, and regular. The 

 lines are rather thin and usually straight, but occasionally they are bent or otherwise distorted or 

 bisected. 



The degree of polarization is rather high. It varies somewhat in different grains and in the 

 same aspect of a grain. It is not so high as in M. arundinacea var. (Commercial No. 1). 



With selenite the quadrants are usually well defined 

 and irregular in shape and unequal in size. The colors 

 are not pure. 



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

 tion the grains color a fair blue-violet; with 0.125 per 

 cent solution they color lightly and the color deepens 

 somewhat. It is not quite so deep as that of the grains 

 of M. arundinacea var. (Commercial No. 1). After heat- 

 ing in water until the grains are completely gelatinized, 

 the solution colors fairly and the grains deeply on the 

 addition of iodine. After boiling for 2 minutes the solu- 

 tion colors deeply and the grain-residues lightly. The 

 capsules are colored violet with an excess of iodine. 



Staining Reactions. — With gentian violet and with 

 safranin the grains begin to stain at once and in 30 

 minutes they are fairly stained, some more than others. 

 The color is less than that of the grains of M. arun- 

 dinacea var. (Commercial No. 1). 



Temperature Reaction.- — The temperature of gelatin- 

 ization is 77° to 78.5° C, mean 77.75°. 



Effects of Various Reagents. — With chloral hydrate-iodine the reaction begins in many grains in 

 a minute. About two-thirds of the grains are completely gelatinized in 15 minutes and nearly all 

 in 40 minutes. The reaction is the same qualitatively as that of the grains of M. arundinacea var. 

 (Commercial No. 1). 



The reaction with chromic add begins in some grains in 15 seconds and in all in 30 seconds, 

 and is over in 4J^ minutes. It is the same qualitatively as that of the grains of M. arundinacea 

 var. (Commercial No. 1). 



The reaction with pyrogallic add begins in most grains in 45 seconds, and four-fifths are com- 

 pletely gelatinized in 8 minutes. The reaction is qualitatively the same as that of the grains of 

 M. arundinacea var. (Commercial No. 1). 



Reaction with /errtc chloride begins in a few grains in 13^ minutes. About two-fifths are com- 

 pletely gelatinized in 17 minutes; one-half are completely or nearly completely gelatinized in 23 

 minutes, two-thirds in an hour, and all are completely gelatinized in 4^/^ hours. The reaction is 

 the same as that of the grains of M. arundinacea var. (Commercial No. 1). 



The reaction with Purdy's solution begins in a few grains in 2 minutes, and a few are partially 

 gelatinized at the end of 30 minutes. The reaction is the same qualitatively as in M. arundinacea 

 var. (Conunercial No. 1). 



Curve of Reaction- Intensities of Starch of Calathei 

 vandenheckei. 



