218 BOTANICAL GAZETTE [SEPTEMBER 
g. The entire xylem system of the root is bordered peripherally 
by cambium. 
Grateful acknowledgments are due to Professor JoHN M., Covut- 
TER and Dr. W. J. G. LANp, under whose direction the investigation 
was conducted, and to Professor CHARLES J. CHAMBERLAIN for 
abundance of material. 
THE UNIVERSITY OF CHICAGO 
LITERATURE CITED 
1. Bower, F. O., On the comparative morphology of the leaf in vascular cryp 
togams and gymnosperms. Phil. Trans. Roy. Soc. 1'75:583. 1884. 
- Bronentart, A., Note un nouveau genre de Cycadées du Mexique. Ann. 
Sci. Nat. Bot. TIL. 5:5. 
3- Dorery, HELEN A., ie tics of Ceratozamia: a physiological study. 
Bot. GAZETTE 452412. 1908. 
Grecc, W. H., Anomalous thickening in the roots of Cycas Seemannt Al. 
Braun. Avninls of Botany 1:63. 1 
- Karsten, H., Organographische Retrachtunpen der Zamia muricata Willd. 
Abh. der Betlig Akad. 193. 1856. 
6. Marre, Henri, Recherches sur l’appareil libéro-ligneux des Cycadacées. 
Caen. 1904. 
, Note préliminaire sur des germinations de Cycadacées. Rennes. 
N 
> 
un 
1907. 
8. Merrentus, G., Beitrige zur Anatomie der Cycadeen. Abh. Konigl. Sachs. 
Gesells. Wiss. '7:565. 1860 
9. Pearson, H. W., Anatomy of the seedling of Bowenia spectabilis. Annals 
of Botany 12:475. 1898. 
10. REINEE, J., Beitrage zur Kenntniss der Gymnospermen Wurzel. Morph. 
Abh. Leipz. 1873. (Reviewed in Just’s Bot. Jahrb. 1:205. 1873 ) a 
Ir. SmirH, Frances GRAcE, Morphology of the trunk and develope 0 
microsporangits of cycads. Bot, GAZETTE 43:187. 1907- der 
12. Sotms-Laupacu, H. Grar zu, ee phone der Stangeria und 
iibrigen Cycadeen. Bot. Zeit. 48:17 
13. VAN TiEGHEM, Pu., Symetrie de ar des plantes. Ann. Sci. 
V. 13:204. 1873. 
14. Von Mout, H., Ueber den Bau der Cycadeen Stammes und sein nee 
zu dem Stammes der Coniferen und Baumfarnen. Abh. Konigl. 
Miinch, 1832. Vermischte Schriften 195. 1845. ? der 
Warne, E., Ein Paar nachtrigliche Notizen iiber die Entwickeluns 
Cycadeen. Bot. Zeit. 36:737. 1878. with 
- WorspDELL, W. C., The anatomy of the stem of Macrozamia com mpared 
that of the other genera of Cycadeae. Annals of Botany 10:601- ”“ 
Nat. Bot. 
m4 
sy 
al 
an 
