GENUS VTCIA. 



385 



Effects of Various Reagen's. — With chloral hydrate-iodine the reaction begins in some of the grains 

 in 20 seconds. About one-fiftli are completely gelatinized in 5 minutes, one-half in 15 minutes, two- 

 thirds in 30 minutes, and five-sevenths in an hour. It is the same qualitatively as that of the grains 

 of V. saliva. 



The reaction with chromic add begins in most of the grains in 30 seconds and in all in 50 seconds. 

 It is over in IJ^ minutes. It is the same qualitatively a.s that of the graias of F. saliva. 



The reaction with jtyrogallic acid begins in all of the grains in 30 seconds and is over in IJ^ 

 minutes. It is the same qualitatively as that of the grains of V. saliva. 



With ferric chloride the reaction begins in a few gi-ains in 2 minutes. About three-fifths are 

 gelatinized in 25 minutes and nearly all in three-fourths of an hour. It is the same qualitatively as 

 that of the grains of V. sativa. 



The reaction with Piirdy's solution begins in nearly all the grains in a minute. A few are com- 

 pletely and many partially gelatinized in 4 minutes, and most are completely gelatinized in 25 min- 

 utes. It is the same qualitatively as that of the grains of V. saliva. 



Differentiation of Certain Starches of the Genus Vicia. 



Histological Chakacteristics. 

 Conspicuous Forms. 



V. saliva: Simple. Bean-shaped, elongated oval, ovoid, 

 lenticular and broadly lenticular, pyriform, round 

 to nearly round. 



V. villosa: Essentially the same as in V. saliva. 



V. faba: Essentially the same as in V. saliva. 



V. fulyens: Essentially the same as in V. saliva, but with 

 a larger proportion of rounded forms. 



V. gerardi: Essentially the same as in V. saliva. 



Hilum — Form, Number, and Position. 



V. saliva: In rounded forms it may be a small, clear, round, 

 slightly refractive spot; in elongated forms it is usu- 

 ally represented by a median fissure which tends to 

 have bisected ends. Position centric or slightly ec- 

 centric. 



V. vUlosa: Essentially the same as in V. saliva. Position 

 centric or slightly eccentric. 



V. faba: Essentially the same as in V. sativa. Position 

 centric or slightly eccentric. 



F. fvlgens: Essentially the same as in V. saliva. Position 

 centric or slightly eccentric. 



V. gerardi: Essentially the same as in V. sativa. Position 

 centric or slightly eccentric. 



Lamelloe — General Characteristics and Number. 



V. sativa: Very distinct, coarse, continuous; tending gen- 

 erally to follow the margin of the grain. 4 to 12. 



V. villosa: Essentially the same as in V. sativa. 4 

 to 10. 



V. faba: Essentially the same as in V. sativa. 6 to 8. 



V. ftdgens: Essentially the same as in V. saliva. S to 12. 



Size. 



V. saliva: G to 42^, commonly 26^. 

 V. villosa: 6 to 44/j, commonly 28m. 

 V. faba: 4 to 42m, commonly 29m. 

 V. fulgens: 4 to 40m, commonly 27m. 

 V. gerardi: 4 to 40m, commonly 28m. 



PoLARiscopic Properties. 



Figure. 



V. sativa: Centric or slightly eccentric, variable in form; 

 in the round grains a cross; in the elongated grains 

 chiefly a long, broad mesial line with bisected 

 ends. 



V. villosa: Essentially the same as in V. saliva. 



V. faba: Essentially the same as in V. saliva. 



V. fulgens: Essentially the same as in V. saliva. 



V. gerardi: Essentially the same as in V. saliva. 



PoLARiscopic Properties. — Continued. 



Degree of Polarization. 



V. saliva: High, as a rule. 



V. villosa: High, but lower than in V. saliva. 



V. faba: High, higher than in V. saliva. 



V. fulgens: High, higher than in V. saliva, with greater 



range. 

 V. gerardi: High, about the same or higher than in V. 



sativa. 



Polarization with Selenite— Quadrants and Colors. 



V. sativa: Quadrants well-defined, irregular in shape, un- 

 equal in size, often subdivided. Colors usually pure. 



V. villosa: Quadrants same as in V. sativa. Colors usually 

 pure. 



V. faba: Quadrants same as in V. saliva. Colors usually 

 pure. 



V. fulgens: Quadrants same as in V. saliva. Colors usu- 

 ally pure, but greater variation than in V. saliva. 



V. gerardi: Quadrants same as in V. sativa. Colors usu- 

 ally pure, slightly purer than in V. sativa. 



Iodine Reactions. 



Intensity and Color. 



V. sativa: Fairly deep; blue- violet. 



V. villosa: Fairly deep, deeper than in V. sativa; violet. 



V.faba: Fairly deep, deeper than in F. sativa, pinkish 



violet. 

 F. fulgens: Fairly deep, deeper than inF. sativa; blue- violet. 

 F. gerardi: Fairly deep, the same as in V. sativa; violet. 



Staining Reactions. 



With Gentian Violet. 



V. sativa: Very light. 



V. villosa: Very light, slightly less than in V. sativa. 



V. faba: Light, deeper than in F. saliva. 



V. fulgens: Very light, slightly less than in F. sativa. 



V. gerardi: Very light, slightly less than in F. sativa. 



With Safranin. 



V. sativa: Light. 



V. villosa: Light, slightly less than in F. saliva. 

 V. faba: Light, slightly more than in F. saliva. 

 V. fidgens: Light, slightly less than in F. sativa. 

 V. gerardi: Light, slightly less than in F. sativa. 



Temperature op Gel.^tinization. 



F. sativa: 72 to 73° C, mean 72.5°. 

 F. villosa: 6.5 to 67° C, mean 66°. 

 F. faba: 64 to 66° C, mean 65°. 

 F. fulgens: 71 to 73° C, mean 72°. 

 V. gerardi: 70 to 72° C, mean 71°. 



