GENUS ZAMIA. 899 



grains a fairly deep, brilliant indigo-blue, a few with a reddish tint. After boiling for 2 minutes and 

 then treating with iodine, the solution becomes a very deep l)lue, while most of the grain-residues 

 color very lightly, but a few fairly deep. The capsules become of a light reddish-violet color. With 

 an excess of iodine the grain-residues color a deep reddish-purple and the capsules a deep helio- 

 trope. 



Staining Reactions. With gentian violet the grains begin to color slightly immediately and in 

 30 minutes are lightly stained. 



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



Temperature Reaction. The temperature of gelatinization is 76 to 77 C, mean 76.5. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins in a few grains im- 

 mediately. A small number are gelatinized in 5 minutes, about one-tenth in 30 minutes, and about 

 one-eighth in an hour. Only a few scattered grains color an old-rose at once, but gradually they 

 take on this tint. The hilum becomes very distinct. As the clefts or the cavity sometimes found 

 at the hilum swell, bubbles often are formed here which are expelled during the reaction. The deep 

 blue color which accompanies gelatinization starts at the pressure facets of dome-shaped grains 

 and gradually spreads. In grains in which a protuberance exists, the reaction starts at this point, 

 while in round and nearly round grains a ring of dark blue color is formed marginally and gradually 

 spreads over the entire grain. The gelatinized grains are uniformly swollen and retain the general 

 shape of the untreated grain. 



The reaction with chromic acid begins in a few grains in 30 seconds. A small number are dis- 

 solved in 3 muiutes, nearly all in 6 minutes, and all in 10 minutes. The hilum swells and a branched 

 longitudinal fissure proceeds from each side of the hilum towards the distal end. The lamellae 

 become sharply defined and striated, and are first gelatinized around the hilum and between the two 

 longitudinal fissures. During gelatinization a great mass of refractive granules appears which grad- 

 ually passes into solution. The grain continues to swell and finally the capsule is ruptured, usually 

 at the distal end. The gelatinized starch gradually flows out and it and the capsule pass into solution. 



Reaction with pyrogallic acid begins immediately. A few grains are gelatinized in 30 seconds, 

 about three-fifths in a minute, about five-sixths in 5 minutes, and all but rare resistant grains in 6 

 minutes. The reaction is usually complete in these in 10 minutes, but rarely a grain may take 20 

 minutes for gelatinization. The hilum swells and a bubble appears, which enlarges and then grad- 

 ually disappears as a succession of small bubbles is expelled. Usually either one or two large, 

 branched, longitudinal canals pass from the hilum towards the distal end and the lamellae become 

 sharply defined and striated. As the starch is gelatinized a number of refractive granules appear, 

 most of which are soon gelatinized. The reaction is more rapid at the distal than at the proximal 

 end, where the lamellae are comparatively resistant. In the round and nearly round grains, the 

 starch is gelatinized without the formation of the large, branched fissures, but the reaction proceeds 

 more rapidly from the distal to the proximal end than in the reverse direction. The gelatinized 

 grains are much swollen and distortctl. 



The reaction with ferric chloride begins in a few grains in 2 minutes. A small number are gelat- 

 inized in 5 minutes, very slight progress occurs in 30 minutes, and only a few grains are gelatinized 

 even in an hour. The hilum swells and a large bubble usually appears, which is very persistent. A 

 transparent, lustrous border forms marginally, which may increase in width until the entire grain 

 is involved, followed by gelatinization. In other grains gelatinization begins at the distal end 

 accompanied by rapid distension of the capsule at this point. When the reaction reaches the prox- 

 imal end, the resistant starch here is broken into large granules, which are finallj^ gelatinized. The 

 gelatinized grains are swollen and distorted. 



Reaction with Pvrdi/s solution begins in a few grains in a minute and a very small number are 

 gelatinized in 5 minutes. There is very little progress in 60 minutes, at the end of which time the 

 reaction is complete in only a few grains. The hilum swells and the lamellte become more sharply 

 defined and striated. Usually one or two branched, longitudinal fissures pass from the hilum to the 

 distal end. Gelatinization begins at the distal end, or in dome-shaped and hemispherical grains at 

 the corners limiting the distal margin, and advances rather rapidly until near the proximal end, 

 at which point the lamella? are very resistant. Many refractive granules appear during gelatiniza- 

 tion, which may persist for an hour, but in most of the very few grains that are affected they are 

 finally gelatinized. The gelatuiized grains are swollen and somewhat distorted, but many of them 

 closely resemble the imtreated grain in shape. 



