240 General Notes. [ April, 
abundant supply of seed has been secured. Phellodendron Amurense is 
a native of Manchuria, where, according to Maximonicz, it becomes a 
handsome, thick-leaved tree, fifty feet high, and with a trunk a foot in 
diameter. It occurs also in Japan, where a second species has been de- 
tected. 
Phellodendron can be characterized by its corky bark; opposite, un- 
equally pinnate leaves; oblong, lanceolate, acuminate, sharply serrate 
leaflets ; small, green, dicecious flowers, borne at the extremity of the 
branches in loose corymbs; and by its five seeders, black, odoriferous, 
pea-shaped drupes, with flattened seeds, which in our species are two 
lines long, and covered with a shining black testa. 
Its nearest North American allies are Ptelea and Xanthoxylum. — 
C. S. SARGENT. 
MODIFICATION OF THE GLUMES OF GRASSES DEPENDING ON THE 
Sex or THE FLOWERS. — Fournier gives as the result of his study 
of the grasses of Mexico the following statement: Among grasses with 
separated sexes, the female flowers differ very little, if at all, as re- 
gards the situation or form of the floral envelopes, when the sexes are 
borne on different plants ; but when the plant is moneecious the glumes 
of the two sexes are widely different. These differences are most 
marked in certain genera of Chloride, normally dicecious and acci- 
dentally moncecious. The grass described by Engelmann under the 
name Buchlée dactyloides is a curious example in point. Beside this is 
now placed Opizia stolonifera, of which Presl had seen only the female 
plant. Although the female flowers of these plants differ very widely, 
their male plants resemble each other so much that they have been put 
in the same genus. Casiostega humilis is the male form of Buchlée, 
and ©. anomala is the male form of Opizia. A 
Liviné AND FossıL OAKS or EUROPE COMPARED BY De SAPORTA. 
— Before the end of the Miocene, Europe possessed oaks which closely 
resembled Quercus Cerris. They had cupules of the same kind as the 
one now living, and the fruit matured in the second year. Three species 
in Auvergne belonged to the type of Quercus Robur, and “ did not differ 
from the forms of this group more than these forms differ from one an- 
other.” Quercus pedunculata, sessiliflora, and pubescens are relatively 
recent. In the middle of France, at least, these races have been pre- 
ceded by other oaks, which have since partly disappeared and partly 
- have been confined to a region farther south. On the other hand, 
species which now occupy only limited stations where they are threat- 
ened with extinction, like Quercus Cerris in France, appear to have had 
direct representatives there at an epoch relatively remote. 
ABSORPTION or CARBONIC ACID BY THE VEGETABLE CELL Walt 
BY Proressor Boum, or Vienna. — Carbonic acid is atmospheric alr, 
absorbed not only by the contents of green cells but by the cell walls 
_ themselyes. Branches dried at 100° C. absorb more carbonic acid than 
