INTERCELLULAR SECRETIONS. 253 
passages, a new formation of cells takes place by the division of 
the older cells (Figs. 174, 175), so that finally the fully devel- 
Fie. 174. Fie. 175. 
Fig. 174.—Beginning of the new formation of cells in the boundary cells (Miller), 
Fie. 175,—Around the intercellular passage, which has become extended as an oil- 
‘space, a layer of tabular daughter-cells (secerning cells) has been formed. Transverse 
section through a branch of the root of Inula Helenium (Miller). 
oped resin-passage or balsam-passage is located in a special 
Fig. 176. : Fie, 177. 
Fie. 176.—Longitudinal section (a) and transverse section ((b) through a balsam-pas- 
sage (oil-space) of Rad. Inula. Be : : 
Fie. 177.—Central portion of an oil-space from Rhizoma] Arnice, on & longitudinal 
section; 0, oil-space; t, daughter-cells which have not yet become depressed. 
