526 



STARCHES OP LILIACE^. 



projection first formed is invaginated suddenly and deeply. This process of gelatinization and 

 swelling moves on down the grain mitil all parts are affected, the distal end last. As the grain becomes 

 fully swollen, the invaginated portion above referred to is pushed out. The swollen grains are very 

 large and are irregular. They are smooth and rounded at the proximal end, and sacculated, wrinkled, 

 and folded at the distal end. 



The reaction with Purdy's solution begins in a few seconds and is over in a minute. It appears 

 to be practically identical with that of pyrogallic acid. The main difference is that the bubble 

 formation at the hilum does not occur so frequently with this reagent, and the resulting swollen 

 grain is larger and retains less of the original form of the grain. 



STARCH OF TULIPA SYLVESTRIS. (Plate 31, figs. 183 and 184. Chart 130.) 



Histological Characteristics. — In form the grains are simple and with few exceptions isolated. 

 No pressure facets were observed on the isolated grains. The surface is usually regular. A few 

 grains have lateral depressions near the hilum; and rarely grains are seen with nipple-like processes 

 at the sides near proximal end. The conspicuous forms among the large grains are triangular with 

 curved base and rounded angles, somewhat clam-shell- 

 shaped and elongated triangular with curved base and 

 rounded angles varying to slightly pyriform. The con- 

 spicuous forms of the small grains are slightly flattened 

 ellipsoidal, pyriform, ovoid, and round. The grains are 

 flattened and when viewed on edge they are frequently 

 seen to be narrower at the distal end. They are slightly 

 less regular than those of T. hageri. 



The hilum is a fairly distinct refractive spot, which 

 has a range of eccentricity from one-fourth to one-sixth 

 of the longitudinal axis, in most grains one-fifth. A short 

 transverse fissure at the distal margin of the hilum is 

 occasionally present. 



The majority of the larmlloe are fine but fairly dis- 

 tinct, and frequently grouped between a few disseminated, 

 rather coarse and refractive ones; but occasionally grains 

 are found in which the lamellae are quite distinct and 

 coarse throughout. In many of the grains one to three 

 coarse, refractive lamellae are particularly conspicuous at 

 varying distances between the hilum and the distal end, 

 frequently between one-half and two-thirds. In the larger grains an average of 42 lamellae was 

 counted. 



The size of the smallest grains is 3 by 3ai; the largest broadened grains are 46 by 52/^; the larger 

 elongated forms are 52 by 43/^ in length and breadth. The common size of the broadened grains 

 is 34 by 2Six, and of the elongated grains 30 by 24;^ in length and breadth. 



Polariscopic Properties. — The figure is usually eccentric, distinct, and fairly clear-cut, 

 lines are generally thick and straight, but are expanded, especially at the distal margin 

 bent or bisected. It is the same as in the grains of T. hageri. 



The degree of polarization is fairly high, without much variation in the different grains or in 

 the same aspect of a given grain. It is higher than in T. hageri. 



With selenite the quadrants are fairly well defined; they are regular in shape and unequal in 

 size. The blue is quite pure, but the yellow is not pure, as in T. hageri. 



Iodine Reactions. — With 0.25 per cent Lugol's solution the grains color a deep blue-violet; 

 with 0.125 per cent solution they color fairly and the color deepens rapidly. It is slightly deeper 

 than that of the grains of T. hageri. After heating in water until all the grains are complcjtely gelat- 

 inized, the solution colors fairly and the swollen grains deeply on the addition of iodine. After 

 boiling for 2 minutes the solution colors very deeply and the grain-residues lightly. The capsules 

 all color a red-violet with an excess of iodine. 



Staining Reactions. — With gentian violet the grains begin to stain at once and in 30 minutes 

 are fairly stained, some more than others. It is the same intensity as that of the grains of T. hageri. 



Curve of Reaction-Intensities of Starch of TuHpa 

 sylvestria. 



Its 

 They are 



