1908] DORET Y—CERATOZAMIA 219 
, On the origin of transfusion tissue in the leaves of gymnospermous 
plants. Jour. Linn. Soc. 33:118. 1897. 
, Comparative anatomy of the Cycadaceae. Jour. Linn. Soc. 33:437- 
17. 
18. 
1898. 
19. , The anatomical structure of Bowenia spectabilis Hook. Annals of 
Botany 14:159. 1900. 
EXPLANATION OF PLATES XII-XVI 
All the drawings except figs. 6-11, 16, 21-25 were made with the aid of a 
camera lucida. The abbreviations used are as follows: A, B, C, D, the four 
main cotyledonary bundles; An, Bn, Cn, Dn, the corresponding root poles; 
C, median bundle of developed cotyledon; D, median bundle of aborted one; 
4, a’, lateral bundles of aborted cotyledon; 6, ¥, lateral bundles of developed 
one; ad, adaxial face of cotyledon; c, cotyledon; cb, cambium; ob’, cb”, extra- 
fascicular cambium; cl, coleorhiza; ct, connective tissue of root; ¢x, cortex; ofx, 
centrifugal xylem; cpw, centripetal xylem; d, d’, lateral traces of first leaf; ¢, ¢, 
middle traces of same; /f, foliar bundles; /*, /%, f%,/% four principal groups of 
foliar bundles; g, cotyledonary trace; h, vascular system of hypocotyl; 7, vas- 
cular system of root; imd, initiation of mucilage duct; 4, sclerenchyma; ky root 
cap; J, leaf; m, meristematic plate; md, mucilage duct; », medulla; 9, indices 
of radial cell division in medulla; /, plumule; ph, phloem; ph, protophloem; 
Px, protoxylem; px’, rupture of tissues caused by protoxylem; 4, plerome; 7, root; 
» Suspensor; #, leaf trace; ér, transfusion tissue; ™, stem bundles; v, periblem; 
©, stipules; x, xylem; y, cork; z, anomalous thickening. 
Fics. 1-3.—Stages in intraseminal development showing single lateral 
cotyledon and gradual enlargement of its base to encompass axis. 5. 
Fic. 6.—Rupture of micropylar end of seed coat and protrusion of base of 
x4 
embryo. i 
Fic. 7.—Bending of base of embryo and exit of plumule. xX}. 
Fic. 8.—A of root. X#. 
Fics. 9, 10.—Young seedlings. 
Fic. 1oa.—Longitudinal section through tip of unfolding leaf. 
Fic. 11.—Dissection of aerial portion of two-year-old seedling. 
Fic, 12,—Diagram showing spiral phyllotaxy of later leaves. Nat. size. 
Fic. 13.—Transyerse section of cotyledon. 8. : 
Fic. 13¢.—Transverse section of cotyledons of embryo developed on clinostat. 
< 
Nat. size. 
Fic. 14.—Transverse section of upper portion of cotyledon showing tendency 
- X8 
og 15.—Transverse section of same cotyledon nearer tip. x8. 
IG. 16.—Diagram to show venation of cotyledon. 
Fic 17.—Mesarch bundle from lower portion of cotyledon. 380. ss 
Fic. 18.—Exarch bundle from the middle region of cotyledon. X 380. 
