NODAL ANATOMY AND THE MORPHOLOGY OF STIPULES 453 
with any other structures. Stipules, sheaths, ligules and similar 
modifications of the base of the petiole are dependent in position and 
character on the anatomy of the node, and seem thus to be essentially 
homologous. 
6. A leaf provided with two distinct stipules is more ancient in 
type than one with a sheathing base. 
BussEY Institution, 
Harvard University 
BIBLIOGRAPHY. 
1. Colomb, M. G. Recherches sur les Stipules. Ann. Sci. Nat., Bot. ser. 7, 6: 1-76. 
1887. 
2. Domin, K. Ein Beitrag zur Morphologic des Dikotylenblattes. Bull. Internat. 
Acad. Sci. Prague. 191 1. 
3. Sinnott, E. W. The Anatomy of the Node as an Aid in the Classification of 
Angiosperms. Am. Jour. Bot. i: 303-322. 1914. 
DESCRIPTION OF FIGURES OF PLATE XLIV. 
Fig. I. Diagram showing relation of stipules to lateral leaf -traces and course 
of traces in the base of the petiole. 
Fig. 2. Very young leaf of Robinia, showing stipules and blade. 
Fig. 3. Base of petiole of Rosa showing relation of free portions of stipules to 
insertion of lateral leaf-trace bundles. 
Fig. 4. Transverse section just below node of Hamamelis (typical trilacunar 
dicotyledon) showing departure of the three leaf-traces and the swellings opposite 
them. 
Fig. 5. Transv rse section a little higher up than in jig. 4, showing the forma- 
tion and innervation of the stipules. 
Fig. 6. Transverse section at the node of Eucalyptus (typical unilacunar 
dicotyledon) showing absence of lateral leaf-traces and stipular swellings. 
Fig. 7. Transverse section at node of Potamogeton showing general nodal 
topography, with formation and innervation of stipules. 
