246 DIFFERENTIATION AND SPECIFICITY OF STARCHES. 



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

 ones compressed to half their width. Length about 8/i. 



Bromus pendulinus 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 21ju. 



Bromus arduennensis Kunth. Dry seed. Grains rounded to oblong, occasionally triangular and 

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

 from the narrow aspect the central cavity is slit-like. Length about I'Z/x. 



Bromus asper Murr. Dry seed. Grains roundetl-oval to elongated rod-shaped and conical; usually 

 twice as long as broad. Leng-th 5 to 7yu. 



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

 as broad as long. Length 6 to 7n. 



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; many somewhat irregular, 

 and several more or less constricted. Length aliout 14/^. 



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

 about 4 to 5n, width 1.3 to l.Sfi. 



Bro7nus divaricaius Rohde. Dry seed. Grains rounded-oval to lanceolate, frequently irregular and 

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

 compressed. Length about 15;u. 



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

 slightly constricted in the middle; 1.33 to 3 and 4 times as long as broad; the broad ones 

 compressed to half their width. Length about lO/u. 



Bromus confertus Biebrst. Dry seed. Grains minute, rounded or oblong. Length 2.5^, width 

 hardly 1.4/i. 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 {Trilicum, Agropyrum, Secale, Elymus, 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 polyhedral, and are more 

 or less markedly compressed. Size about lOyu. The grains are simple, although separated- 

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



Cyperacew. 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, undoubtedly simple grains 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. (Cyperacem.) Dry seed. Grains rounded or oval, frequently rounded- 

 angular. Size 8 to ll/i. 



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

 what irregular and angular. Size 8 to 10/i. Compound plastids are also observed. 



Mariscus jacquini Humb., Kunth. (Cyperacece.) Dry seed. Grains rounded or polygonal, occa- 

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



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



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

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

 tids are lacking. 



Heleocharis palustris R. Br. (Cyperacece.) Dry seed. Grains rounded, usually angular. Size 

 about 8m. 



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

 pressed to half their width. Size about 8 to lO/z. 



Scirpus mucronatus Linn. (Cyperacece.) Dry seed. Grains polyhetlral, slightly compressed. Size 

 about Sm- 



Sdrpus maritimus Linn. (Cyperacece.) Dry. Grains spherical or slightly angular. Size about 5^. 



