GENEHA TRITEI.EIA AND LACHENALIA. 600 



With seleniie the quadrants are fairly well defined, usually somewhat irregular in shape, and 

 unequal in size. The colors are fairly pure. 



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

 with 0.125 per cent solution they color lightly, and the color deepens slowly. After heating in 

 water until all the grains are completely gelatinized, the solution colors fairly and the gelatinized 

 grains very deeply on the addition of iodine. After boiling for 2 minutes the solution colors deeply 

 and the grain-residues fairly to lightly. The capsules color a violet with excess of iodine, and most 

 of them retain blue-reacting starch at their proximal end. 



Staining Reactions. — With gentian violet the grains begin to stain very lightly in 2 minutes and 

 in 30 minutes are lightly stained, one as much as another. 



With safranin the grains begin to stain, lightly in 1}/^ minutes, and in 30 minutes are fairly 

 stained, one as much as another. 



Temperature Reaction. — The temperature of gelatinization is 69.3° to 69.6° C, mean 69.45°. 



Effects of Various Reagents. — ^With chloral hydrate-iodine the reaction begins in most grains in 2 

 minutes. About half are gelatinized in 25 minutes and two-thirds in 45 minutes without much further 

 reaction in an hour. The process starts at the distal end at the corners and edges of the facets. 

 These points become dark and swell, and the reaction extends upward to the interior of the grain. 

 There is a well-marked hne of demarcation between the gelatinized and non-gelatinized portions. 

 The gelatinized grains are fairly large and of a uniform dark color, and retain much of the original 

 form. 



Reaction with chromic acid begins in some grains in 15 seconds and in all in 45 seconds, and it 

 is over in 4 minutes. The reaction starts at the hilum, which swells somewhat, and from it very 

 fine, rather indistinct striae radiate; a bubble forms at the hilum and increases and then decreases 

 in size, finally disappearing. The less resistant portion of the grain is transformed into a gelatinous 

 mass, while the more resistant part collects at the margin in the form of a rather thin, finely striated 

 ring, sometimes indistinctly banded. This ring becomes thinner and transparent as the grain swells, 

 especially at the proximal end. It is finally dissolved at one or two points. The inner, gelatinized 

 starch flows out and dissolves, and then the remainder of the ring dissolves, but not rapidly, the 

 distal end being the last to disappear. 



The reaction with pyrogallic acid begins in all the grains in 30 seconds and is over in 5 minutes. 

 The reaction originates at the hilum, which swells, and very fine striae appear throughout the grain. 

 A large bubble forms at the hilum and increases to a great size, then decrea.ses, and finally disappears. 

 The less resistant starch passes into a gelatinous mass, and the more resistant starch forms a rather 

 thin, finely striated band at the margin. This band becomes thinner and transparent as the grain 

 swells. The gelatinized grains are large, wrinkled, and folded, and do not retain the original form 

 of the grain. 



The reaction with ferric chloride begins in many grains in 2 minutes. About three-fourths are 

 gelatinized in 15 minutes, four-fifths in 35 minutes, almost all in 55 minutes, and all in IJ^ hours. 

 The reaction starts at the distal end, at the corners and edges of the facets, which become gelatinous 

 and swell. The process extends upward from here, and when it nears the portion of the grain near 

 the hilum, this part is invaded by internal fissures dividing it into several portions separated by bands 

 of gelatinized starch. These portions gelatinize independently of one another. In a few grains the 

 process of gelatinization affects the whole margin before it reaches the interior of the grain. The 

 gelatinized grains are very large, thin-walled, wrinkled, sacculated, and irregular in form, and do 

 not retain any of the original form. 



The reaction with Purdy's solution begins slightly in many grains in 45 seconds. About half 

 are partially gelatinized in 15 minutes, about one-third almost completely gelatinized in 50 minutes, 

 and one-half are partially and one-half completely gelatinized in 1^4, hours. The reaction appears 

 to be the same qxialitatively as that to pyrogallic acid. 



GENUS LACHENALIA. 



LachenaUa comprises 42 species, 9 of which are in cultivation. The members of this genus are 

 natives of the region of the Cape of Good Hope, and popularly known as Cape cowslips. The 

 starches from two sources were .studied: L. pendula Ait. and L. tricolor var. luieola (L. luteola Jacq.). 



