38 Elementary Botany 



In the Date Palm (fig. 45) the lower part of the cotyledon 

 lengthens, pushing the root and plumule out of the seed, whilst 

 the rest of it remains in contact with the albumen absorbing it. 

 In the Wheat (fig. 46) the cotyledon is developed to form 

 a plate where it is in contact with the endosperm, and is known 

 as the scutellum. This serves the purpose of absorbing the 



G' G" 



Fig. 48.— Germinating Bean : a,bj 

 cotj-^ledons ; c, rf.Jeaves ; c, ter- 

 minal bud ; /i, primary root ; ^, 

 lateral roots. 



Fig. 49.— Longitudinal section through the 

 apex of a root of A spidistra ela-tior \ 

 wh, root-cap ; m, pith ; o, epidermis ; o', 

 narrow spiral vessels ; C', broad reticu- 

 late vessels. 



albumen. In this case there is at once a growth of the root 

 causing a rupture of the sheath surrounding it, which remains 

 attached to the axis forming the coleorhiza (fig. 47). In some 

 few monocotyledonous plants, where there are exalbuminous 

 seeds (as in the natural orders Naiadacese, Alismacese, &:c.), the 



