GENUS MARANTA. 821 



Polariscopic Properties. The figure is usually eccentric and distinct. Its lines are very clearly 

 defined and some tend to widen materially as they are nearer the margin of the grain. They are so 

 arranged usually that one corresponds with the longitudinal axis of the grain; in some grains they 

 divide the ficUl obliquely. 



The degree of polarization is high, about the same as that of Maranta arundinacea, but with 

 greater variation. It varies a little in different grains, in different aspects of a given grain, and 

 occasionallj' in the same aspect of a grain. 



With sdenite the quadrants are very well defined, irregirlar in shape, and unequal in size. The 

 colors are generally pure. 



Iodine Reactions. With 0.25 per cent Lugol's solution the grains color a fairly deep blue- 

 violet, the same depth of color but more blue than in M. arundinacea; wdth 0.125 per cent solution 

 they tint lightly, the color deepens slowly, but more rapidly than in M. arundinacea. When heated 

 in water until complete gelatinization has occurred the solution is colored a deep indigo on the 

 addition of iodine; the gelatinized grains are colored deeply to lightly, mostly the latter. The gelat- 

 inized grains are smooth, rounded, and nodular, and granular at the distal end. After boiling for 

 2 minutes the solution is much more intensely colored and the grain-residues but little or not at 

 all. With an excess of iodine all the capsules take on a red-violet color and are folded and twisted. 



Staining Reactions. With gentian violet the grains begin to stain slightly at once and after 30 

 minutes they are fairly colored, slightly deeper than in M. arundinacea. 



AVith safranin staining begins immediately and after 30 minutes the grains are fairly deeply 

 stained, slightly deeper than in M. arundinacea. 



Temperature Reaction. The temperature of gelatinization is 71 to 73" C, mean 72. 



Effects of Various Reagents. With chloral hydrate-iodine some grains show the beginning of 

 a reaction at once. A few are gelatinized in 45 seconds, more than half \n\]4, minutes, nearlj' all in 

 2 minutes, and all but rare resistant grains in 43/2 minutes, in which latter the reaction may not be 

 complete until 15 minutes. The lamellae become indistinct, but the hilum grows more distinct as 

 a black spot, or is fissured. All the grains take on a light violet tint, the margin becomes clearer 

 and forms a clear ring which spreads inward, causing the central portion to assume a lighter, more 

 refractive appearance. The lamellae reappear in the marginal clear space, this being accompanied 

 by the development of dark points on the margin, especially on the nodular projections and at the 

 distal end. Protrusion and gelatinization begin at these points and then proceed gradually towards 

 the hilum. The grain as a whole in the meantime becomes colored a dark violet. Gelatinization 

 may begin at opposite ends of the grain at the same time and proceed centrally, gradually approach- 

 ing the hilum, which finally swells. 



Reaction with chromic acid begins in two-thirds of the grains in 15 seconds and in the remain- 

 ing one-third in 45 seconds. Nearly all are dissolved in 1}^ minutes and all in 4 minutes. The 

 lamellae are indistinct, but the hilum becomes distinct and swells, accompanied by the formation 

 of fine, radiating stria throughout the grain. Coarse striae or folds appear at the distal end of the 

 grain. The margin dissolves at a point above the swollen hilum, and the space formed by the swol- 

 len hilum opens out. One faintly lamellated, finely striated crescent usually forms at the distal 

 end of the grain, which generally does not split off, but if it does, a second much fainter one forms. 

 After the widening out of the swollen hilum, the grain gradually becomes clearer and finally dissolves. 

 When the hilum is fissured, the fissures widen and deepen, and extend through the grain. One por- 

 tion of the margin now dissolves and the fissures widen, followed by the solution of the grain. 



With pyrogallic acid evidences of swelling appear in most grains at once. Several are gelat- 

 inized in 10 seconds, nearly all in 35 seconds, all but rare resistant grains in 50 seconds, and all 

 within 2 minutes. There is no further change. The hilum and lamelliE become very distinct. 

 The hilum swells and highly refractive lines, probably fissures in the interior of the grain, extend 

 on each side to the margin. The hilimi gradually becomes larger and fine striae appear in the grain. 

 Later coarse striae or folds develop at the distal end. The hilum gradually enlarges, and the lamel- 

 lated substance of the grain is pushed out to the margin until a large, gelatinized grain is formed 

 which exhibits a clear inner space that is surrounded by a dark margin having still darker striated 

 bands and a granular mass at the distal end. In grains in which the hilum is centric, granular 

 masses are formed at two parts of the grain. If the hilum is fissm-ed, the fissures widen, but there 

 are no essential differences in the type of swelling. The fully gelatinized grains are large, clear, 

 oval, and somewhat folded. 



