24G DIFFERENTIATION AND SPECIFICITY OF STARCHES. 



Bromus canadensis Michx. Dnj seed. — Grains rounded, oval, oval spindle-shaped, conical; the broad 

 ones compressed to half their width. Length about 8fi. 



Bromus yendulinus Schrad. Dry seed. — Grains rounded-oval to oblong and conical; sometimes con- 

 stricted in the middle; frequently irregular; compressed to about one-half and one-third 

 their width. Length about 21/t. 



Bromus ardu^nnensis Kunth. Dry seed. — Grains rounded to oblong, occasionally triangular and 

 quadrangular with blunt angles; the broad ones compressed to about one-third their \\idth; 

 from the narrow aspect the central cavity is slit-like. Length about 12/x. 



Bromus asper Mutt. Dry seed. — Grains rounded-oval to elongated rod-shaped and conical; usually 

 twice as long as broad. Length 5 to 7/x. 



Bromus secalinus Linn. Dry seed. — Grains oval to elongated-lanceolate; one-third to two-thirds 

 as broad as long. Length 6 to 7yu. 



Bromus diandrus Curt. Hort. beroL, 1855. Dry seed. — Grains rounded-oval and rounded-triangular 

 to rod-shaped and elongated-conical; the broad ones compressed to one-third their width; 

 narrow ones about 3 times as long as broad and almost terete; mfny somewhat irregular, 

 and several more or less constricted. Length about 14/i. 



Bromus mollis Linn. Dry seed. — Grains rarely rounded-oval, usually oblong or lanceolate. Length 

 about 4 to 5fi, width L3 to LS/j. 



Bromus divaricatus Rohde. Dry seed. — Grains romaded-oval to lanceolate, frequently irregular and 

 angular, often triangular; one-fourth to almost as broad as long; the broad ones strongly 

 compressed. Length about 15/i. 



Bromus vestitus Nees. Dry seed. — Grains oval to lanceolate and lanceolate-linear; occasionally 

 slightly constricted in the middle; L33 to 3 and 4 times as long as broad; the broad ones 

 compressed to half their width. Length about lOju. 



Bromus conferlus Biebrst. Dry seed. — Grains minute, rounded or oblong. Length 2.5^1, width 

 hardly L4jli. If the starch-grains are freed from the cells they frequently hang together in 

 globular masses, but these are unquestionably not compound grains. At least not any are 

 ever noted within the uninjured cell. 



Hordeacece [Triticum, Agropyrum, Secale, Elynius, Hordeum, Mgilops, Braconnotia) . Seeds. — Besides 

 the large grains which are related to the centric lenticular type, there are small grains in 

 great numbers observed in the inner tissues, while only the small grains are found in the 

 outer cells. They are spherical, rounded-angular, or even almost polyhech-al, and are more 

 or less markedly compressed. Size about 10/i. The grains are simple, although separatcd- 

 grains are also found among them. Whole doublets and triplets are rarely observed. 



CyperacecE. — ^The dry seeds contain starch-grains which are rounded or oval, sometimes compressed 

 into a lenticular form; many of them are angular or polyhedral and resemble separated- 

 grains; the latter are, however, imdoubtedly simple gi-ains which are merely changed in form 

 as a result of pressure. Plastids which resemble compound starch-grains and which become 

 yellow or golden yellow when treated with iodine are often observed. 



Cyperus flavescens Linn. {Cyperacece.) Dry seed. — Grains roimded or oval, frequently rounded- 

 angular. Size 8 to 11/i. 



Cyperus strigosus Linn. (Cyperaceoe.) Dry. — Grains rounded, oval, oval-conical, frequently some- 

 what irregular and angular. Size 8 to lOfi. Compound plastids are also observed. 



Mariscus jacquini Humb., Kunth. (Cyperaceoe.) Dry seed. — Grains rounded or polj'gonal, occa- 

 sionally irregular, strongly compressed. Size about 12/i, thickness 1 to 2ju. 



Mariscus umbellatus Vahl. {Cyperacece.) Dry seed. — Grains as in the preceding. 



Kyllingia odorala Vahl. {Cyperacece ) Dry seed. — Grains rounded or rounded-oval, angular or poly- 

 gonal, compressed to half or more of their width. Size about 7/i, thickness about 3ii. Plas- 

 tids are lacking. 



Heleocharis paluMris R. Br. (Cyperaceoe.) Dry seed. — Grains rounded, usually angular. Size 

 about Sfi. 



Heleocharis ovuta R. Br. (Cyperacece.) Dry seed. — Grains roimded or rounded-angular; and com- 

 pressed to half their width. Size about 8 to 10^. 



Scirpus mucronalus Linn. (Cyperacece.) Dry seed. — Grains polyhedi-al, slightly compressed. Size 

 al:)out 8^. 



Scirpus marilitnus Linn. (Cypo-acece.) Dry. — Grains spherical or slightly angular. Size about 5^. 



