SCHIZOGENIC PASSAGES. 257 
among themselves; yet aconformity to some law in the position 
of these receptacles is sometimes apparent upon a_trans- 
verse ‘section. ‘lhe root-stock of Arnica, for example, shows 
a large balsam-passage (Fig. 182) before each fibro-vascu-. 
lar bundle. A similar arrangement may be seen to exist in 
aie 
Fia. 182.—Portion of a transverse section from the underground stem (rhizome) of 
Arnica montana. Before each xylem-ray (wood-bundle) 1, there is a very large oil 
space; 0, b, cavities formed by the laceration of the fundamental tissue; a, epidermis 
_ of the root (epiblema); m, medulla, The cells of the epidermis are spirally striped; in 
the surroundings of the oil-spaces are drops of oil which have escaped. Compare also 
Berg's “ Atlas,” Plates 8, 9, 10. ; aii 
Radix Angelice and R. Levistici, in Rhizoma Imperatorie and 
others, although, in the course of development, which is not = 
