212 PHARMACEUTICAL BOTANY 



3. Endocarp, an irregular line of inner epidermal cells which is 

 differentiated into two regions, the interplacental region and the 

 placental region. The interplacental (inner) epidermis shows its 

 cells elongated into numerous thin- walled glandular hairs which con- 

 tain an abundance of balsam; the placental region covers the six 

 bifid placenta which extend into the cavity of the capsule. Its 

 (inner) epidermis is composed of mucilaginous cells. 



4. Seeds. These are minute blackish bodies attached to the pla- 

 cental twigs of the placentae. Some of them may have been torn off 

 in cutting the section. 



FIG. 105. Photomicrograph of a transverse section of a mericarp of Foeni- 

 culum vulgare, showing epicarp (A), mesocarp (B), endocarp (F), vitta (C), endo- 

 sperm of seed (>), carpophore (G) and fibro-vascular bundle in primary rib (). 

 (Highly magnified.) % 



Histology of a Typical Mericarp, Foaniculum. This five-angled 

 fruit, in transverse section, shows a concave commissural and convex 

 dorsal surface. Passing from the surfaces toward the center we note : 



1. Epicarp, or outer covering tissue, composed of colorless epider- 

 mal cells and small stomata. The epidermal cells in cross-section 

 appear rectangular, while in surface view they are both polygonal 

 and rectangular. 



2. Mesocarp, of several layers of thin- walled colorless isodia- 

 metric cells, beneath which are two to several additional layers of 

 thicker- walled cells with brownish walls. Through the angles or 

 rib portions of the mesocarp extend the fibro-vascular bundles. 



