GENUS SPARAXIS. 



759 



With safranin the grains begin to stain at once, and in 30 minutes are light to fairly deep in 

 color. The tint is distinctly deeper than in S. grandijlora alba. 



Temperature Reaction.- The temperature of gelatinization is 72 to 73 C, mean 72.5. 



Effects of Various Reagents. With chloral hydrate-iodine the reaction begins immediately. A 

 few grains arc gelatinized in 30 seconds and all but a few resistant grains in a minute. The reaction 

 is usually complete in tlie latter in 33^2 minutes. Rarely a broadly triangular grain with curved 

 base and rounded angles is observed, in which gelatinization does not reach completion in 18 min- 

 utes. The grains generally swell uniformly during the reaction, but in the broadly triangular form 

 a small, rounded protuberance appears at the proximal end. The reaction is qualitatively the same 

 as in S. grandiflwa alba. 



The reaction begins immediatelj- with chromic acid. A few grains are dissolved in 15 seconds, 

 nearly all in 30 seconds, and all but rare resistant grains in a minute. The reaction is complete in 

 the latter in 1^ minutes. It is qualitatively the same as in S. grandijlora alba. 



The reaction begins immediately ^\^th pyrogallic acid. A few are gelatinized in 15 seconds, 

 and all but a few resistant grains in 25 seconds. The reaction is complete in the latter in 45 seconds. 

 It is qualitatively the same as in S. grandijlora alba. 



With ferric chloride the reaction begins immediately. A few grains are gelatinized in 30 sec- 

 onds, nearly all in a minute, and all but rare resistant grains in 3 minutes. The reaction is usually 

 complete in the latter within 10 minutes, but very rarely a broadly triangular grain resists the reagent 

 for 25 minutes. The reaction is qualitatively the same as in S. grandijlora alba. 



The reaction begins at once with Purdy's solution. A few grains are gelatinized in 15 seconds, 

 nearly all in 45 seconds, and all but rare resistant grains in a minute. The reaction is usually com- 

 plete in the latter in 10 minutes. A much smaller number of grains in which the reaction has only 

 proceeded as far as the first stages is found in this starch than in S. grandijlora alba. The reaction 

 is qualitatively the same as in S. grandijlora alba. 



Differentiation of Certain Starches of the Genus Sparaxis. 



Histological Characteristics. 

 Conspicuous Forms. 



S. grandiflora alba: Almost wholly single, few compound 

 grains, some aggregates or clumps, isolated grains 

 usually have sharply defined pressure facets, sur- 

 face sometimes irregular. Dome-shaped with 

 sometimes a pointed base, hemispherical, round 

 and nearly round. 



S. var. (Alherline): Essentially the same as in S. grandi- 

 flora alba, but with a large proportion of large 

 ovoid, pyriform, and broadly triangular grains. 



Hilum Form, Number, and Position. 



S. grandijiora alba: Form clear, round spot, or irregular 

 cavity, 2 or more short fissures. Position centric, 

 or eccentric to about 0.33 or 0.25 of the longitudinal 

 a.xis. 



5. var. (Alberiine): Form essentially the same as in 

 S. grandiflora alba. Position centric, or eccentric 

 to about 0.33 to 0.2 of the longitudinal axis. 



LamellcE General Characteristics and Number. 



S. grandiflora alba: Usually indistinct, but occasionally 

 fairly coarse complete rings or having the form 

 of the outline of the grain. About 7 to 9 on roimd 

 and dome-shaped grains. 



<S var. (Alberiine): Essentially the same as in S. grandi-- 

 flora alba, but less often demonstrable. The same 

 as in iS. grandiflora alba. 



Size. 

 S. grandiflora alba: From 3 to 30n, commonly 12ju. 

 S. var. (Albertine): From 3 to 32m, commonly 13^. 



POLARISCOPIC PrOPEKTIES. 



Figure. 

 S. grandiflora alba: Centric or eccentric, lines frequently 

 not distinct throughout, often either bent or 

 bisected. Double figures fairly frequent. 

 50 



grandi- 

 Colors 



PoLARiscopic Properties. Continued. 

 Figure. Continued. 

 8. var. {Alberiine): The same as in S. grandiflora alba, ex- 

 cept that the hnes are more often distinct through- 

 out their length, and figure more often eccentric. 

 Degree of Polarization. 

 S. grandiflora alba: Fair to high. Variable in different 



grains and in a given aspect of a grain, 

 S. var. (Albertine): Fair to lugh. On the whole higher, 

 and less variable in a given aspect of a grain. 



Polarization with Selenite Quadrants and Colors. 

 S. grandijlora alba: Quadrants usually clearly defined, 

 generally irregular in shape and unequal in size. 

 Colors not pure. 

 S. var. (Albertine): Quadrants the same as in S. 

 Jiora alba, but on the whole less irregular, 

 not pure. 



Iodine Reactions. 

 Intensity and Color. 

 S. grandiflora alba: Fairly deep; blue-violet. 

 S. var. (Albertine): Deep, much deeper than in S. 

 gratidiflora alba; blue with reddish tint. 



Staining Reactions. 

 With Gentian Violet. 

 S. grandiflora alba: Light. 



iS. var. (Alberiine): Light to fair, deeper than in S. 

 grandijlora alba. 



With Safranin. 

 S. grandijlora alba: Light. 



S. var. (Albertine): Light to fairiy deep, distinctly 

 deeper than in S. grandiflora alba. 



Temperature of Gelatinization. 

 S. grandiflora alba: 71 to 72 C, mean 71.5. 

 S. var. (Albertine): 72 to 73 C, mean 72.5. 



