82 CROCION ACHLYDOPHYLLUM . 
hadrome and leptome forming open collateral vascular bundles. 
The intrastelar fundamental tissue is composed of thin-walled 
parenchymatous cells varying in size with no marked elongation 
in any direction. The tracheae are spiral, annular, and scalari- 
form in type, the last mentioned are only occasionally met with. 
The endodermis limiting the stele is much more conspicuous 
than in the hypocotyl both as to uniformity of shape and to the 
lateral suberization of the cellwalls which, in cross section, appear 
as dark spots. The remaining cells of the extrastelar fundamental 
tissue are thin-walled, polygonal in outline and well filled with 
starch. There are no intercellular cavities found either in the 
cortex or medulla. Cutinization is so pronouced in the cells of the 
epidermis that the cell cavities are remarkably reduced. 
ANATOMY OF THE MATURE PLANT. 
THE Root. (Fig. 13-14). 
The dermatogen (Fig. 13) is composed of cells which have 
cuticularised to some extent along the lateral and inner walls and 
to such an extent along the outer walls that the cuticular membrane 
so formed becomes. stripped off at irregular intervals forming 
surface projections. The length of the cells is approximately 
twice their width. The cells of the hypodermis differ in no marked 
degree from those of the dermatogen in size; their cell walls, how- 
ever, are not very much thickened. The entire extrastelar ground- 
tissue is composed of rather large polygonal thin-walled paren- 
chymatous cells very much elongated along their vertical axes 
containing many protoplasmic granules, and an abundance of 
starch grains which are found as far outward as the epidermis 
inclusive (Fig. 13 St.). Calcium oxalate crystal aggregates are 
very common. ‘Two layers of cells next to the hypodermis as seen 
in longitudinal section (Fig. 14) are from 3 to 5 times as long as 
broad, the others though of the same width as the former are from 
6.5 to 10 times as long. ‘The endodermis though not very distinctive 
is readily recognized from the rest of the extrastelar fundamental 
tissue without and from the adjoining tissue within. 
The pericycle, well marked in young roots, loses its chara- 
cteristic appearance partially or entirely, so that it is only occasion- 
ally able to be differentiated in older roots. The secondary changes 
in roots that are quite mature are most evident in the hadrome of 
the fibrovascular bundle where it occupies the entire central portion 
