2l8 PHARMACEUTICAL BOTANY 



1. Spermoderm of three regions, viz.: Palisade cells, Column cells, 

 and Spongy Parenchyma. The palisade cell layer is composed of 

 vertically elongated thick-walled cells which are covered on their 

 outer faces by a clear glistening cuticle. The cells are 60 to Son long 

 and 12 to 2o/z wide. The column cells, found forming a layer 

 directly beneath the palisade zone, are hour-glass-shaped and 25 to 

 35/u long by 14 to 35/z wide. 



The spongy parenchyma forms a zone of several layers of thin- 

 walled parenchyma cells, the cells of the outer and inner layers being 

 considerably smaller than the middle layers. 



2. Embryo, the two cotyledons of which make up the greatest bulk. 

 These are composed of an epidermis covering over a region of meso- 

 phyll. The mesophyll is constituted of moderately thick-walled 

 cells which contain ellipsoidal and kidney-shaped starch grains up 

 to 65/4 in length. A conspicuous branching cleft will be seen in the 

 larger grains. 



In the Lima Bean, the nourishment is stored in the embryo during 

 the growth of the seed. It is, therefore, exalbuminous . 



