2 i8 
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 So/x long 
and 12 to 20/x wide. The column cells, found forming a layer 
directly beneath the palisade zone, are hour-glass-shaped and 25 to 
35 » long by 14 to 35 n 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/* 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. 
