Igtt] CHARLES—ANATOMY OF MARATTIA IOI 
Fic. 23.—Origin of the medullary strand from the inner surface of a 
strand a the dictyostele. 188. 
IG. 24.—Diagram of the strand of the dictyostele at fig. 23, showing the 
_Telation of the origins of medullary strand and root trace. 
25.—Diagram of the vascular cylinder, showing the relation of the 
medullary strand to leaf gaps and leaf traces 
Fic. 26.—Transverse section of the cotyledonary node, showing the 
departure of an exarch leaf trace. X 400. 
Fics. 27-30.—Transverse sections of the cotyledonary trace, showing 
the eee from exarch to mesarch protoxylem. X 400. 
G. 31.—Transverse section of the apical region of a sporeling with six 
a showing the triangular apical cell and large segment; at the left above 
is the youngest leaf trace. X1 
Fic. 32.—Transverse section of apical region of a sporeling with 25 leaves, 
showing an irregular apical cell. X 188. 
Fic, 33.—Transverse section of an older stem, showing a four-sided apical 
cell. X 188. 
IG. 34.—Transverse section of a stem 6mm. in diameter, showing two 
Spihignes blocks of cells. 188 
35.—Transverse section of the apex of a stem 12 mm. in diameter, 
shies a meristematic region. 188 
Fic. 36.—Longitudinal section of the apical region of a very young spore- 
ling. X 400. 
IG. 37.—Longitudinal section of the apical region of a stem with 30 
leaves; the tissue below the apical cell is pith; at the sides is vascular meristem. 
188. 
Fic. 38.—Transverse section of a young stele, showing a frequent relation 
of sieve tubes to endodermis. X 400. 
Fic. 39.—Transverse section near the apex, showing early origin of root 
from vascular meristem. 130. 
Fics. 40, 41.—Transverse sections of later stages in the development of 
roots than fig. 39. X 130. 
Fic. 42.—Transverse section of a mucilage duct, ‘showing a cell disin- 
tegrating in the mucilage. X 400. 
