Pammel — Anatomical Characters of Seeds of Leguminosae. Ill 



yond the light line and below the membrana externa (cuticle) 

 is mucilaginous. This swells, the canals take up the water, 

 and by capillarity it passes into the inner parts of the seed. 

 The light line allows little water to pass. It swells only 

 slightly, but is passively stretched, and in this way causes the 

 enlarging of the canals. When transpiration takes place act- 

 ively and there is no water to repair the loss, the light line 

 assumes its normal position and the canals close. 



OSTEOSCLERIDS. 



Various names have been given to these cells by different 

 writers: Sanduhrzellen (Harz), Saulenzellen (Sempolowski), 

 Tragerzellen ( various writers ) , cellules en sablier ( Chalon ) , cell- 

 ules de soutien (Marliere), Knochenformigezellen (Tschirch), 

 colonne (Mattirolo and Buscalioni). For reasons stated 

 above, the classification of Tschirch (265, 1 : 204) has here 

 been followed. 



The osteosclerids almost universally accompany the Mal- 

 pighian cells, in the order Leguminosae, Some exceptions 

 occur, as in Arachis, where these cells are like those of the 

 nutrient layer. In Phaseolus vulgaris the cells are prismatic. 

 In some species they are much longer than in others. The 

 length also varies in different parts of the same seed, being 

 greater towards the hilar region, where the parts are not so 

 strongly compressed. Where the Malpighian cells curve, the 

 osteosclerids gradually become shorter and merge into the 

 star-shaped parenchyma of the hilum. In Phaseolus lunatus 

 they are somewhat funnel-shaped. In Trifolium and Medi- 

 cago these cells are what the Germans call hourglass-shaped 

 (sanduhrformige). The cells are here broad at the base with a 

 triangular intercellular space. In other cases the intercellular 

 space is somewhat prismatic and large, as in Lupinus albus 

 and Vicia Faba. In some species it is much reduced. This 

 is often a question of position, since its size and character vary 

 in the same seed. 



The walls are thickened and in some cases marked by 

 longitudinal canals. Some of the German writers refer to 

 these cells as ** streifig verdickt " (99, 2 : 612). This char- 

 acter is well marked in some tribes, notably Trifolieae 2i.i[id. 



