424 ON SEEDLINGS 



subtransparent, forming a thick layer at the back of each cotyledon, 

 and a thin continuous layer at their edges and ends. 



Embryo large, curved, nearly equal in length to the endosperm, 

 central, conforming in general outline to that of the seed, pale 

 yellow ; cotyledons linear-oblong or oblong, obtuse, entire, slightly 

 A R. 



FIG. 276. Sesbania cegyptiaca, x 13. A, longitudinal section of 

 seed : B, radicle ; H, hilum. B, transverse section of seed near 

 the end containing the radicle, B : P, endosperm ; C, coty- 

 ledons. C, transverse section of seed towards end opposite 

 the radicle : P, endosperm ; C, cotyledons. 



indented near the middle owing to a thickening at the hilum, and 

 somewhat unequal at the base owing to the position of the radicle, 

 rather thick, but flat, and both taken together presenting a some- 

 what rectangular appearance in transverse section ; radicle stout, 

 oblong, obtuse, accumbent and curved round to the micropyle at the 

 base of the ventral aspect and outside the cotyledons. 



Sesbania tomentosa, Hook, et Arn. (fig. 277). 



Primary root long, nearly vertical, with many lateral branches 

 thickened near their ends. 



Hypocotyl erect, woody, 3-4 cm. long, about 1 mm. thick, terete 

 near its base, ridged higher up by reason of the decurrent petioles 

 of the cotyledons, densely covered with red dots especially below, 

 otherwise of a paler green below. 



Cotyledons subsessile, 1-5-2 cm. long, 8-10 mm. broad, unequal, 1 

 one oblong, the other oblong-obovate, entire, convex, obscurely 

 penninerved, rather thick, glabrous, dull green above, paler beneath, 

 not very persistent. 



1 Inequality of cotyledons probably accidental. 



