TYPE 3. GRAINS SIMPLE, CENTRIC, OVAL. 207 



Luzula nivea Desv. Dry seed. Grains rounded, more or less angular, frequently with sharp angles; 

 homogeneous; the larger ones compressed at about one-third their width. Size 11 to 13/li. 



Luzula forsteri Desv. and L. muUifiora Lejeum. Dry seed. Grains rounded, occasionally somewhat 

 angular, compressed. Size 20^. Thickness sometimes only 1.5 and 2^. 



Juncus baltieus Dethard. Dry seed. Grains rounded, many of them somewhat angular, with blunt, 

 rarel}' sharp, angles; somewhat compressed, extending halfway; homogeneous or granular; 

 sometimes with small central cavity. Size 9 to 12/j. 



Juncus glaucus Ehrli. ; J. effusus Linn. Dry seed. Grains rounded, quadrangular with rounded 

 corners, or polyhedral with sharp angles, usually irregular; compressed at about one-third; 

 homogeneous or granular; sometimes hollow. Size 9 to 12/x. 



Juncus bulbosus Linn.; J. comprcssus Jacq. Dry seed. Grains rounded or roundish-angular, or 

 often irregular with blunt or sharp corners; compressed; homogeneous or granular. Size IB^i. 



Juncus acutijlorus Ehrh. ; J. sylvaticus Reichard, var. inacrocephalus. Dry seed. Grains rounded, 

 frequently more or less angular; compressed, sometimes to about one-half the mdth; homo- 

 geneous or granular. Size about ISju. 



Salsola soda Linn. {Chenopodiacew.) Dry cotyledons. Grains rounded to oval, usually angular and 

 irregular; the broad ones laterally compressed at about one-half or over; homogeneous; 

 with a long slit when seen from the narrow side. Size 11 to 13^. The grains approach type 3. 

 Among them some compound grains of two or many part-grains. Seeds obtained from 

 various places were examined. Those whose starch-grains have just been described were 

 green, as were also the tissues of the cotyledons. Some of the starch-grains were also green, 

 proving that they were formed in the chlorophyl. These seeds were rich in starch, and also 

 contained much oil. On the other hand, in seeds of a bro^ii color with colorless tissues in the 

 cotyledons, considerably more oil and remarkedly little starch was found. The latter are 

 a little smaller (up to 8m), rounded oval, or angular with rounded corners, and are compressed. 

 The seed of other species of Salsola soda examined contained no starch, possibly oil replacing 

 the starch in ripe Salsola soda. 



Trapa natatis Linn. {Onagonocew .) Dry cotyledons. Grains circular, rounded-oval to triangular 

 to quadrangular; one-third to one-half as thick as broad; usually with indistinct and scant 

 lamelliE; frequentlj' with a small central cavity from which delicate fissures radiate; with a 

 marked slit seen in the narrow aspect. Size to 32/x. 



Type 3. Grains Simple, Centric, Oval. 



Grains oval or oblong, with equal blunt ends, rarely with unequal or pointed ends; seen on 

 end, circular or compressed; more or less angular when crowded. Hilum in the center, and in a 

 general way of the same shape as the grain, but relatively much longer and more compressed. Lamel- 

 lae, as a rule, alike at two opposite parts, most marked at the ends. The true terete grains, when 

 dried, show fissures which radiate in all directions from the longitudinal axis; the compressed forms, 

 almost without exception, show a fissure which coincides with the largest plane, which fissure when 

 seen from the narrow side appears as a dark median line, and from the broad aspect has a very 

 indistinct or almost invisible border. The fissure is sometimes crossed at right angles by another, 

 but more frequently onlj' cross-fissures radiate from it. The grains are usually symmetrical on 

 all sides, but the compressed forms show a decided inclination, which is more marked along 

 one margin than along the opposite, and they therefore become plano-convex, kidney-shaped, 

 elliptical, or triangular with rounded angles. This type, going over on one side to the centric- 

 spherical and on the other to the centric-lenticular, is found with certainty only in spores and seeds, 

 and seems to be entirely wanting in other parts of the plant. Semicompound and compound grains 

 are occasionallj' found among the simple ones, and they usually consist of few, and, almost without 

 exception, part-grains of equal size. 



Chara aspera Willd. {Algoe.) Dry bulbils of the lowest nodes of the stem. The bulbils consist of a 

 single cell, with a structureless membrane, and filled with two kinds of starch-grains : 

 (1) Large grains, spherical or oval; two-thirds to as broad as long; the widest ones compressed 

 to three-foiu-th.s of the grain; usually without distinct lamella; with central, spherical, or 

 oblong hilum; usually with marked fissures radiating from the center; the compressed forms 

 have a slit coinciding with the plane. Length 40 to 100^, width lOfx, thickness to bOfi. 



