GENERA CHIONODOXA AND PU8CHKINIA. 



551 



tinctly lower temperature of gelatinization, less sensitivity to chloral hydrate-iodine, pyrogallic 

 acid, and ferric chloride, but greater sensitivity to Purdy's solution; and in comparison with C. 

 sardensis it has a higher degree of polarization, less sensitiveness to iodine, a somewhat higher 

 temperature of gelatinization, less sensitivity to chloral hydrate-iodine, ferric chloride, and Purdy's 

 solution, and greater sensitivity to pyrogaUic acid. 



GENUS PUSCHKINIA. 



This genus consists of only one or possibly two species of bulbous plants, native of Southern 

 Asia. Its alliance with genera that are represented in this investigation has been referred to under 

 Scilla. The only universally recognized species is P. scilloides Adams {Adamsia scilloides Willd.). 

 The other and the questionable species is P. libanolica Zicc. {P. sicula), probably a variety, and 

 designated P. scilloides var. libanolica by Boissier. Starches of both were studied. 



Chart No. 147. 



P I GV T 

 S 



PS CI PA 

 ~ PC PS 



STARCH OF PUSCHKINIA SCILLOIDES. (Plate 37, figs. 217 and 218. Chart 147.) 



Histological Characteristics. — In form the grains are almost always simple and for the most part 

 isolated. There are some compound grains, usually consisting of one large and two or three small 

 components, the latter arranged at the sides and distal end of the large grain, and often partially 

 separated by fissures, but held together by common lamellae. There are many small aggregates, usu- 

 ally of two grains, one smaller than the other and adherent to the distal end of the larger grain. There 

 are very few pressure facets on the isolated grains. The surface of the grains is somewhat irregular, 

 due to irregular development or to secondary additions to the primary grain, often deposited on 

 the distal end and sides, the longitudinal axis of which 

 does not correspond with that of the primary part of the 

 grain. In the compound grains, inequality in size of the 

 components and variability of their positions with respect 

 to one another also give rise to variations in surface. The 

 conspicuous forms are ovoid and oval, which may have 

 both ends rounded or the distal end squared and broader 

 than the proximal end; triangular with rounded corners; 

 also pyramidal, spherical, quadrilateral with rounded 

 corners, and rarely lenticular, and pyriform. The grains 

 when seen on edge are not flattened, but are not so thick 

 at the distal end as at the proximal end. 



The hilum is a distinct, fairly large round spot, ec- 

 centric usually one-third to one-fourth of the longitud- 

 inal axis, and in or near the median line. Rarely in the 

 smallest grains it is centric. Two or more hila are often 

 linearly arranged in a single grain and may or may not 

 be separated by fissures. The hilum is often fissured and 

 the fissure may be narrow and short, broad and long, 

 ragged or clear-cut; a single transverse or longitudinal 

 fissure that is straight or curved on each side of the central point; or two fissures forming a cross; 

 or three or more fissures springing from a central point. In some grains with more than one hilum 

 one irregular fissure runs through all of the hila. 



The lamellce are fairly distinct, with usually continuous, coarse, irregular rings, as a rule dis- 

 continuous near distal end of the grains. They are generally coarser and more distinct near the 

 hilum than near the distal end and vary in distinctness and size in different grains. There are 

 6 to 8 on the larger grains. 



The grains vary in size from 4 to 26^. The common size is 15//. 



Polariscopic Properties. — The figure is eccentric, distinct, and not entirely cleai'-cut, and gen- 

 erally somewhat irregular. Its lines are broad, usually broader but not so clearly outlined near 

 the margin; sometimes slightly bent or otherwise distorted, and placed at varying angles to one 

 another; the figure is often complicated, owing to the presence of several component grains of the 

 aggregate or compound, in which case there may be one large and several small figures, or various 

 modifications. 

 37 



Curve of Reaction-Intensities of Starch of Puschkinia 

 scilloides. 



