862 



STARCHES OF HELLEBORACEyE. 



Chart No. 375. 



CI CA P A FC 



grain becomes dark and swells. The gelatinized grains are not very large and usually have a light 

 area in the interior surrounded by an ovoid dark mass. They retain some of their original form. 



The reaction with chromic acid begins at once and is over in 6 seconds. It is so rapid that it is 

 impossible to distinguish the separate steps. 



Reaction with pyrogallic acid begins at once and is over in 10 seconds. It is so rapid that the 

 separate steps can not be made out. The gelatinized grains are large and have a thin capsule that 

 is much wrinkled and folded. They do not retain much of their original form. 



The reaction with feiric chloride begins in many grains in 20 seconds and is over in all in 4 

 minutes. It begins at the distal end where the gelatinization occurs with great swelling. This 

 process spreads upwards and inwards until only a small portion of the grain at the distal end is 

 ungelatinized. This part now becomes partially divided into several pieces of unequal size which 

 are rapidly fully separated, though still retained in the capsule, and gelatinized independently of 

 one another. The gelatinized grains are large, much wrinkled, and distorted, and do not retain 

 any of the original form. 



Reaction with Purdy's solution begins at once and is. over in 8 or 9 seconds. It is so rapid that 

 it is impossible to distinguish the separate steps. The gelatinized grains are large and their capsules 

 are much wrinkled and folded, but thicker than those formed during the reaction with pj-Togallic acid. 



STARCH OF ACT^A SPICATA VAR. RUBRA. (Plate 95, fig. 570. Chart 375.) 



Histological Characteristics. In fo7-m the grains are simple. No compound grains are observed, 

 but there are many aggregates and clumps. Facets are noted on many grains, but their angles and 

 lines are not so sharp as in faceted grains of other genera generallj'. The surface is often irregular as a 

 result of pressure. The conspicuous forms are roimd, ovoid, round with a depression or projection, 

 to hemispherical, and various indefinite forms. Many 

 grains appear like disks and some like concave disks. 



The hilum is either a round or lenticular indistinct 

 spot, sometimes centric, usually eccentric, from slightly 

 to about one-third of the longitudinal axis. A depression 

 which scarcely amounts to a fissure is sometimes found 

 at the hilum, and occasionally it is fissured. 



No lamellas were discernible. 



The grains vary in size; the smaller are 2 by 2/i; the 

 larger are G by Qfi or 7 by 8yu in length and breadth. The 

 common size is 5 by 5fi. 



Polariscopic Properties. The figure is usually eccen- 

 tric, and generally it is indistinct, but when it is observed 

 the lines are usually fairly thick and commonly straight. 



The degree of polarization is low, varying in different 

 grains and sometimes in the same aspect of a grain. It 

 is the same as that of the grains of A. alba. 



With selenite the quadrants are usually fairly well 

 defined, slightly irregular in shape and unequal in size. 

 The colors appear to be pure. 



Iodine Reactions. With 0.25 per cent Lugol's solution the grains all color a very deep blue- 

 violet; with 0.125 per cent solution they color fairly deeply and the color deepens rapidly. It is 

 deeper than that of the grains of A. alba. After heating in water mi til 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 very deeply and the grain-residues lightly or not at 

 all. The capsules all color a violet when an excess of iodine is added. 



Staining Reactions. With gentian imlet the grains begin to color lightly at once and in 30 

 minutes are rather lightly stained. The color is less than that of the grains of A. alba. 



With safranin the grains begin to color very lightly at once and in 30 minutes are very lightly 

 stained. The color is less than that of the grains of A. alba. 



Temperature Reaction. The temperature of gelatinization is 55.5 to 57.5 C, mean 56.5. 



Effects of Variotis Reagents. With chloral hydrate-iodine reaction begins at once and is over in 

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



Curve of Reaction-Intensities of Starch of Acteea spicata 

 var. rubra. 



