406 BOTANICAL GAZETTE [NOVEMBER 
, Epidermis— 
Long unicellular hairs on both faces - - - - A. Purshii 
No long hairs - - - - - - - A. Floridanum 
Bulliform cells well developed on both faces of the leaf A. Purshit 
These restricted to the superior face - - - A. Floridanum 
Mesophyll— 
Forming separate groups between the mestome bundles A. Purshii 
Sometimes united - - - - - - A. Floridanum 
Colorless parenchyma — 
Small groups separating the stereome of the — 
face from the parenchyma sheath - - A, Floridanum 
Frequently only a single cell - ee 
The leaf is altogether thicker and of firmer structure in 4. Mlort- 
danum than in A. Purshii, a fact that perhaps indicates the warmer and 
drier climate of the region to which 4. Floridanum belongs.—THEO. 
Hom, Washington, D. C. 
EXPLANATION OF PLATE XxX. 
Figs. 1-5. Transverse sections of the leaf of Amphicarpum Floridanum. 
Fic. 1. The median part of the blade, showing fine mestome bundles 
and fine groups of bulliform cells on the superior face; Swf, the superior 
face. X 165. 
Fic. 2. Epidermis of the superior face, seen en face; BC, bulliform 
cells; S, the — strata; A, the strata which cover the suas: 
HT, a hair. : 
FIG. 3. ate of epidermis cells from the inferior face, showing @ 
ture somewhat similar to that of proper bulliform cells. X 500. 
struc 
of 
Fig. 4. The margin of the blade, showing the enormous. development 
stereome. X 330. ! 
a 
Fic. 5. One of the largest mestome bundles; /, the colorless pa" 
chyma sheath; Sv, the stereome; £7, the epidermis. X 330. 
Fic. 6. Transverse section of the leaf of 4. Purshii, showing ar 
mestome bundles and three groups of bulliform cells on both faces; Sup 
superior face. X 165. 
