68 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of one root showed that disturbance of the regularity of the endodermis 
was due to cambium cells which developed from the cells of the pericycle 
within the endodermis. Active development of this internal cambium 
Fig. 2. — Endodermis curved and continuity broken by pressure of 
tissues within. Cells x x x 2 show the beginning of separation 
of endodermal cells, x 250. 
caused a bending and displacement of the endodermal ring, owing to an 
intrusion of the newly formed parenchymatous cells. Cambial activity 
Fig. 3. — Separation of endodermis by intrusion of cortex, cor. x 250. 
then ceased, and the endodermis once more became continuous, but 
fresh cambiums appeared again at intervals and more parenchymatous 
cells were intruded among the endodermal cells. At the same time 
