aa 
1906] CHRYSLER—NODES OF GRASSES 15 
nodes, points to their being an ancestral feature, which, in highly 
organized members, has disappeared from most parts of the plant, 
but is retained in the conservative flowering axis. It appears that 
the amphivasal bundles so characteristic of monocotyledons, in all 
probability made their appearance in connection with the entry 
of numerous leaf-trace bundles into the nodes, but that secondarily, 
in certain instances, they are found to be related to branching. 
4. A well-marked, though generally short-lived, cambium occurs 
in the bundles just above the node or near the base of the leaf-sheath 
in certain grasses. This fact is considered to lend support to the 
view that monocotyledons have been derived from some group 
possessing a cambium, probably the dicotyledons. 
5. The anatomical features of the grasses point to their being a 
more highly specialized family than the sedges. 
This investigation has been carried on in the Phanerogamic 
Laboratories of Harvard University. I am indebted to Professor 
G. L. GoopateE for material, and to Professor E. C. JEFFREY for 
material and for advice during the progress of the work. 
HARVARD UNIVERSITY. 
LITERATURE CITED. 
Norte.—Practically nothing bearing immediately on the subject of this 
research has been found in the older literature, so it is not cited here. References 
to it may be found in DEBAry (2), and the text of Kny’s Wandtafein. 
1. Duvat-Jouve, M. J., Etude anatomique de quelques Graminées. Mém. 
Acad. Sci. Montpellier 7: 309-406. 1 
2. DeBary, A., Comparative anatomy of the phanerogams and ferns (trans.). 
1884. ; 
3. ANDERSSON, S., Ueber die Entwickelung der primaren Gefassbundelstrange 
der Monocotylen. Review in Bot. Cent. 38:586, 618. 1889 
4. STRASBURGER, E., pce den Bau und die Verrichtungen der Leitungs- 
: nen. Jena. 1 
5. Scuutze, R., sieht zur vergleichenden Anatomie der Liliaceen, Haemo- 
doraceen, Hypwicidoak: und Velloziaceen. Bot. ‘Jahrb. 17: 295-394. 1893 
6. VAN TiecHEM, Ph., Traité de Botanique. Paris. 1891. 
7. Queva, C., Contribution & l’anatomie des monocotyledonées. I. Tra- 
vaux et Mém. Univ Lille VII. 22:1-162, pls. 1-11. 1 
8. Jerrrey, E. C., The morphology of the central cylinder in the angiosperms 
rans. Can. Inst. 6:1-40. pls. 7-11. 19920. 
