28 Plowman . — The Comparative Anatomy and 
7. On anatomical grounds the Cyperaceae appear to be one of the 
more primitive groups among the Monocotyledons, considerably specialized 
and reduced from the common megaphyllous, possibly hygrophilous ancestor. 
They present a high degree of anatomical unity, not only in floral and 
foliar characters, but also in their internal structure, and especially in the 
mode of occurrence, number, and development of their amphivasal bundles. 
8. The anatomy of the Cyperaceae seems to point strongly to the 
derivation of the Monocotyledons and Dicotyledons from a common 
ancestry which presented characters essentially Dicotyledonous in the 
arrangement and structure of fibrovascular bundles, and in the presence 
of cambial growth. 
In conclusion, I desire to express my obligations to Professor L. L. 
Hudson, of Delaware, Ohio ; to Professor S. F. Poole, of Wichita, Kan. ; 
to Miss Helen Plowman, of Greenville, Ohio ; and to Mr. A. H. Moore, 
Mr. J. G. Hall, and Mr. M. L. Fernald, of Cambridge, Mass., for material ; 
and, above all, to Professor E. C. Jeffrey, for material and for the many 
suggestions and criticisms offered throughout the course of this investigation. 
Phanerogamic Laboratories, Harvard University : 
April , 1905. 
Literature. 
Comparatively little has been written which bears directly upon the subject under consideration, 
but a great many authors refer to it in a more general and incidental way. In the following list no 
attempt has been made to include any but the more interesting and suggestive of the works which 
have been consulted. 
1. Anderssohn, Miss S. : Ueber d. Entwickel. d. primaren Gefassbiindelstrange d. Monokotylen. 
Bihang till K. Sv. Vet. Akad. Handl., xii, 1889, p. 188. 
2. Baranetzky, I. : Sur le developpement des points v^g^tatifs des tiges chez les Monocotyledones. 
Ann. Sci. Nat. Bot., 8 e s£r., tome 3, 1897. 
3. Boodle, L. A. : On lignification of phloem in Helianthus. Annals of Bot., xvi, 61 : 3 x , 1902. 
4. : Comparative Anatomy of the Hymenophyllaceae, Schizaeaceae, and Gleichenia- 
ceae. Annals of Bot., xiv, 1900, p. 455 ; and xv, 1901, pp. 359, 703. 
5. and Worsdell, W. C. : On the Comparative Anatomy of the Casuarinae. 
Annals of Bot., x, 31 : 9, 1894. 
6. Bordet, M. : Recherches anatomiques sur le genre Carex. Revue gen. de Bot., tome 3, 1891. 
7. Caruel, F. : Observations sur la fleur femelle du Carex. Ann. Sci. Nat. Bot., 5 e ser., tome 7, 
1867. 
8. Chauvaud, G. : Sur la mode de formation des faisceaux liberiens de la racine des Cyperacees. 
Bull, de la Soc. bot. de France, 1895, p. 450. 
9. Chrysler, M. A. : The development of the central cylinder of Araceae and Liliaceae. Bot. 
Gaz., 38 : 9, 1904. 
10. Col, A. : Recherches sur la disposition des faisceaux dans la tige et les feuilles de quelques 
Dicotyledones. Ann. Sci. Nat. Bot., 8 e ser., tome 20, 1904. 
11. Cormack, B. G. : On Cambial Development in Equisetum. Annals of Bot., vii, 25 : 3, 1903. 
1 For month of publication — so elsewhere. 
