GENERA ACT^A AND CIMICIFUGA. 



863 



Reaction with chromic add begins at once and is over in 6 seconds. It is so rapid that the dif- 

 ferent steps can not be made out. 



The reaction with pyrogallic acid begins at once and is over in 20 seconds. It is so rapid that 

 the separate steps can not be made out. The gelatinized grains are not so wrinkled, folded, and 

 distorted, but the capsules are thicker than those of A . alba. 



The reaction with ferric chloride begins in many grains in a few seconds and is over in 5J^ min- 

 utes. It is the same qualitatively as that of the grains of A. alba. 



Reaction with Purdy's solution begins at once and is over in 15 seconds. It is so rapid that the 

 details can not be made out. The gelatinized grains have the same appearance as those of A. alba. 



Differentiation of Certain Starches of the Genus Actcea. 



Histological Chabacteristics. 

 Conspicuous Forms. 



A. alba: Simple, many aggregates, many pressure facets, 

 surface often irregular because of facets. Round, 

 ovoid, round with one part flattened or pointed, 

 dome-shaped to hemispherical. 



A. spicata var. rubra: Essentially the same as in .A. 

 alba. 



Hilum — Form, Number, and Position. 



A. alba: Form often invisiblej indistinct, round or len- 

 ticular spot; a depression sometimes crosses the 

 hiluin. Position usually eccentric from slightly to 

 0.33 of the longitudinal axis. 



A. spicala var. rubra: Form the same as in A. alba, 

 except occasionally fissured. Position usually 

 eccentric, as in 4 . alba. 



Lamella — General Cliaraclerislics. 



A. alba: Invisible. 



A. spicata var. rubra: Invisible. 



Size. 



A. alba: From 1 to 13^1, commonly 8m. 



A. spicata var. rubra: From 2 to 7ja, commonly 5;*. 



PoLABiscopic Properties. 

 Figure. 



A. alba: Usually more or less eccentric, generally in- 

 distinct; the lines are rather thick and generally 

 straight. 



A. spicata var. rubra: Essentially the same as in A. alba. 



Degree of Polarizalion. 

 A. alba: Low. 

 A. spicata var. rubra: Low, the same as in i4. alba. 



Polarization with Selenite — Quadrants and Colors. 



A. alba: Quadrants fairly well defined, slightly irregular 



in shape, and unequal in size. Colors appear to 



be pure but dull. 

 A. spicata var. rubra: Quadrants essentially the same 



as in A. alba. The colors appear to be pure but 



dull. 



Iodine Reactions. 



Intensity and Color. 



A. alba: Very deep; blue- violet. 



A. spicata var. rubra: Very deep, deeper than in A. alba; 

 blue- violet. 



Staining Reactions. 

 With Gentian Violet. 

 A. alba: Rather light. 

 A. spicata vax. rubra: Ratherlight, lighter than in A. a^. 



With Safranin. 

 A. alba: Light. 



A. spicata var. rubra: Very light, much lighter than in A. 

 alba. 



Temperature of Gelatinization. 



A. alba: 55 to 57° C, mean 56°. 



A. spicata var. rubra: 55.5 to 57.5° C, mean 56.5°. 



Effects of Various Reagents. 

 Reaction with Chloral Hydrate-Iodine. 

 A. alba: Begins at once; complete in all in 45 seconds. 

 A. spicala var. rubra: Begins at once; complete in all 

 in 1 minute. 



Reaction with Chromic Acid. 

 A. alba: Begins at once; complete in all in 6 seconds. 

 A. spicata var. rubra: Begins at once; complete in all in 

 6 seconds. 



Reaction with Pyrogallic Acid. 

 A. alba: Begins at once; complete in all in 10 seconds. 

 A. spicata var. rubra: Begins at once; complete in all in 

 20 seconds. 



Reaction with Ferric Chloride. 

 A. alba: Begins in many in 20 seconds; complete in all 



in 4 minutes. 

 A. spicata var. rubra: Begins in many in a few seconds; 



complete in 5}4 minutes. 



Reaction with Purdy's Solution. 

 A. alba: Begins at once; complete in all in 8 to 9 seconds. 

 A. spicata var. rubra: Begins at once; complete in all 

 in 15 seconds. 



GENUS CIMICIFUGA. 



This genus, which is allied to Actcea, includes about 10 species of perennial herbs, natives of tem- 

 perate regions of Europe, Siberia, and North America. The best-known form of our American gardens 

 is C. racemosa Nutt. (C serpentaria Prusch.), the common black snakeroot or bugbane, a native of 

 Eastern United States and Canada. The starch from this species was examined as a type of the genus. 



STARCH OF CIMICIFUGA RACEMOSA. (Plate 96, figs. 671 and 572. Chart 376.) 



Histological Characteristics. — In form the grains are simple. No compound grains were observed, 

 but many aggregates and clumps. Many grains have one or more pressure facets. The surface of 



