240 DIFFERENTIATION AND SPECIFICITY OF STARCHES. 



Parnassia palustris Linn. (Sazifragacem.) Dry root-stock. — Grains rounded to elongated-oval, and 

 conical; frequently somewhat irregular; with a cavity, a slit or some fissures. Size about 18yu. 

 Type undetermined. The hilum is eccentric, and often appears to be at the narrow aspect. 



Viola -palustris Linn. {Violaccm.) Dry root-stock. — Grains spherical or rounded-oval. Size about 

 8/11. There are some compound grains of few equal or unequal components. (See type 15.) 



Cereus variabilis Pfeiff. ; Cereus quadrangularis Hort. (Cactacew.) Fresh pith of the stem. — Grains 

 rounded or oval, rarely conical; usually irregular and with either protruding rounded or 

 blunt angles; occasionally projecting on one side into a sharp angle; half to as broad as long; 

 broad ones slightly compressed; one-third to as thick as long; lamellae distinct, mostly more 

 or less irregular, spiral-like, crooked, or noncontinuous in the radius of greatest thickness 

 (in the latter case two to five systems of lamellae may arise) ; hilum more or less eccentric, 

 in some instances about one-fiftieth. Length about lOOyu, thickness 60yu. Among the above 

 are some semi-compound grains as in type 11 and compound ones of few unequal components, 

 type 15. Many much smaller, simple grains and numerous compound and separated-grains 

 were found in the pith of 1.5 inch sprouts, while the separated-grains rarely occurred in older 

 stems. Eccentric structure could occasionally be noticed in the separated-grains. These 

 may possibly have developed from those mentioned above with irregular lamellae, as well as 

 from the semi-compound and compound grains of the mature pith. The starch-grains in the 

 base of the sprouts were decidedly larger than those at the summit. Those in the paren- 

 chyma of the cortex, which on the whole are very scarce, resemble those in the pith. 



Cereus martianus Zuccar. (Cactaceoe.) Fresh pith of the stem. — Grains rounded, occasionally some- 

 what irregular or polyhedral as a result of pressure, sometimes just as thick as broad, some- 

 times compressed into a lenticular form to about two-fifths of their widtli; few lamellae; 

 hilum central or toward one margin. Size about 35/i. The surface of many of the grains is 

 reticulated, probably a form of decomposition. Among the above are some semi-compound 

 grains with 2 and 3 hila, and also some compound forms. Some cells in the parenchyma of 

 the pith are filled with starch. 



Cereus erinaceus Haw.; Echinocactus erinaceus. (Cactacece.) Stem,s. — According to Payen (Ann. 

 Sc. Nat., 1838, ii, p. 18), the grains are usually rounded and irregular; lamellae concentric 

 and with sinuate radial fissures (fentes sinuese). Size about 75fi. These grains were observed 

 in an old exotic stem, and were very scarce. In the pith of a cultivated plant also examined 

 by Payen {too. cit., p. 27; plate 4, fig. e) he found spherical or somewhat irregular grains; 

 lamellae and hilum indistinct. Size about I2fi. There are some doublets. 



Cereus peruvianus Haw.; Cactus peruvianus. (Cactacece.) — According to Payen (loc. cit., p. 24; pi. 6, 

 fig. 21), the grains are usually spherical or ellipsoidal, sometimes irregular; with a few dis- 

 tinct lamellae; hilum frequently visible, about one-fifth eccentric. Size about 30/i. Among 

 these are many compound grains of 2 to 4 components. They frequently have lamellae and 

 an eccentric hilum. 



Cereus Jlagelliformis Mill.; Cactus flag ellif or mis. (Cactacece.) — According to Payen (loc. cit., p. 26, pi. 

 4, fig. d), the grains are irregular; many with upper surface sinuate; compressed to about 

 one-third the width. Size about 15/n. Among these are indistinctly compound grains con- 

 sisting of few components. 



Cereus serpentinus Lagasc; Cactus serpentinus. (Cactacece.) — According to Payen (loc. cit., p. 28, pi. 

 4, fig. m), the grains are round, sometimes uneven; lamellte and hilum usually invisible. Size 

 about 7.5/i; also some doublets. 



Cereus monstrosus DC.; Cactus monstrosus. (Cactacece.) — According to Payen Q,oc. cit., p. 28; pi. 4, 

 fig. n), very few grains are rounded; hilum and lamellae mostly invisible. Size al)out 6^. 



Mamillaria discolor Haw. (Cactacece.) — According to Payen (loc. cit., p. 27, pi. 4, fig. j), the grains are 

 rounded, sometimes uneven; hilum and lamellae invisible. Size 8fi. Some doublets are found 

 among the simple grains. 



Rhipsalis funalis Salm. (Cactacece.) Fresh pith and parenchyma of the cortex. — Grains rounded or 

 rounded-oval, frequently somewhat angular or irregular; slightly compressed, or almost 

 to the middle of their width; occasionally with small delicate, concentric lamellae; from the 

 narrow aspect frequently a longitudinal slit is observed. Size about 22/i, among these are 

 observed some compound grains of small 2 to 4 components. Starch originated in the chlo- 

 rophyl grains. 



