bolts, in practically air-tight contact with its bed, which is cut into the case frame. The bottom of the case is of wood, covered inside with a continuous sheet of tin.

The pump used for forcing air into the case was made by the local tinner at an expense of twenty-five cents. The cylinder of the pump is four inches long and two inches in diameter. A pump of this size will deliver, approximately, one hundred cubic centimeters of air at each stroke, and, at a rate of eighty strokes per minute, it will change the air in the plant-case every thirty minutes.

The air passes from the pump into a filter-flask, which serves as a "stuffing-box," from which it passes into the series of washbottles at a more uniform rate than it would if the pump were connected directly with the wash-bottles. Considerable acid is swept along by the air, from one wash-bottle to the next. This exposes much more surface of acid to the air, but necessitates the inclusion of a bottle at the end of the series to catch the acid thus carried over.

An electric fan, within the case, keeps the air well mixed. A thermograph of convenient size, a recording hygrometer, and a small hygrometer of the "Mitthof's" pattern were also kept in the case. This latter instrument is much more sensitive than the recording hygrometer, and thus indicates any temporary variations in the humidity.

The air in the case can be reduced from saturation to approximately 10 per cent. (hygrograph record) in 12 hours, even when the case is full of living plants. In these experiments the air was continually kept as dry as possible, but the humidity could have been maintained at any desired per cent. within a range limited only by the sensitiveness of the hygrometer used, had the indexarm of the hygrometer been made to open and close mercury switches, operating the circuit of the electric motor which drives the pump. The current of dry air would then have ceased when the desired humidity was reached.

As stated above, the time of death of the plants grown in the case could be determined quite closely. By holding the humidity very low all of the time, the plants dried out at once, and became

FIG. I.

Plant-case for the control of relative humidity. Description in text. (Illustrated with the aid of the Catherine McManes fund.)

practically crisp, as soon as the protoplasm died. There were no temporary recoveries to complicate the determination, as is the case when the humidity relations are fluctuating.

THE DEPARTMENT OF BOTANY,
UNIVERSITY OF MISSOURI,

COLUMBIA, MISSOURI

LOCAL FLORA NOTES — III

BY NORMAN TAYLOR

A goodly number of replies to questions asked in the first two numbers of this series have been already received. The members of the club are so evidently interested that it can be only a matter of short duration until many of the disputed or little known species are fairly well understood, so far as the local range is concerned. Several letters and post cards containing information on the distribution of certain plants have come in, unaccompanied by specimens. Of the authenticity of these statements there is, for the most part, no question. But without a specimen deposited in the club's herbarium, where it constitutes an indisputable record, the present members of the Torrey Club can scarcely expect to silence the questionings of an incredulous posterity. Members are urged to continue their kindly coöperation so that the work may be pushed as rapidly as possible. Specimens submitted in answer to questions will be put in the club herbarium and full acknowledgment will be made.

The list continues :

COMMELINACEAE

1. Commelina hirtella Vahl. The only specimen in our collections is from near Camden, N. J. Judging from the manuals it should be found throughout southern Jersey. Has any one seen it anywhere else in New Jersey except near Camden?

*The local flora range as prescribed by the Club's preliminary catalog of 1888 is as follows: All the state of Connecticut; Long Island; in New York, the counties bordering the Hudson River, up to and including Columbia and Greene, also Sullivan and Delaware counties; all the state of New Jersey; and Pike, Wayne, Monroe, Lackawanna, Luzerne, Northampton, Lehigh, Carbon, Bucks, Berks, Schuylkill, Montgomery, Philadelphia, Delaware, and Chester counties in Pennsylvania.

2. Commelina nudiflora L. While this is apparently a widely distributed plant the only specimen in the collections is from Inwood, N. Y. City. According to general works it should be found from New Jersey southward, etc. Is it found on Long

Island?

PONTEDERIACEAE

1. Pontedetia cordata lancifolia (Muhl.) Morong. While the common pickerel-weed is exceedingly common everywhere, this lanceolate leaved form comes only from Green Pond, N. J. General works say of it "Ont. to N. J.," etc. Has it ever been

found outside of this one pond in New Jersey ?

2. Heteranthera reniformis R. & P. All the specimens in the collections are from New Jersey and Pennsylvania. The exclusion of this plant from the Hudson valley and Connecticut is obviously untrue but specimens at hand do not show its distribution outside of New Jersey and Pennsylvania.

JUNCACEAE

1. Juncus gymnocarpus Coville. Its general distribution is given thus, "In swamps, mountains of Schuylkill and Lebanon counties, Penn." The only specimen in the collections is from the former county. Is the plant localized in the hills near this region or may it be looked for elsewhere?

2. Juncus Balticus Willd. So far as the specimens show this plant grows only on Staten Island. With a general range of from Labrador to southern New York, is this delimitation, as shown by our specimens, reasonable?

3. Juncus Roemerianus Scheele. Through an early though still current error, the plant is credited to New Jersey. No specimens can be found which come from north of the Carolinas, and as an element in our local flora the plant may be ignored. 4. Juncus maritimus Lam. The only station in the New World for this plant is Coney Island, New York City. Years ago it was reported from New Jersey but no specimens are exHow far from Coney Island has the plant spread, if at all? Has any one specimens from New Jersey? Staten Island?

tant.

5. Juncus trifidus L. The only specimen is from Sam's Point, Ulster Co., N. Y. This may well be its southerly point of distribution within our range. However, it should grow in Delaware and Greene counties, particularly in the higher mountains.

6. Juncus dichotomus Ell. New Jersey seems to be the exclusive possessor of this species, according to the specimens at hand. It is supposed to be found from Maine to Florida, near the coast. Does it grow on Long Island or on the coast of Connecticut? On Staten Island?

7. Juncus aristulatus Michx. Our representation of this species is very scanty. Princeton is the only station in New Jersey ; Westchester in Pennsylvania, and Sag Harbor on Long Island. It is supposed to grow near the coast from New York to Florida. Any extension of its present apparaently limited distribution is desirable.

8. Juncus nodosus L. With a general range of from Nova Scotia to Virginia, our specimens are wrongly limiting this plant to a small area from Goshen, Conn., to Lake Grinell, Sussex Co., N. J. The plant is doubtless more widely distributed in our area than this, but how much more?

9. Juncus caesariensis Coville. Griffiths and Landisville, N. J., are the only stations represented in herbaria. Where else in Jersey is the plant found? It is supposed to grow in "Sandy Swamps of S. N. J."

10. Juncus canadensis subcaudatus Engel. This variety is represented by a single specimen from Red Bank, N. J. Its general distribution is from Rhode Island to Pennsylvania and Georgia. Where else, besides the Jersey station, does the plant grow?

II. Juncoides nemorosum (Poll.) Kuntze. So far as known this plant seems to be locally naturalized at Riverdale, New York City. Has any one a record of its being found elsewhere?

12. Juncoides parviflorum (Ehrh.) Coville. There are no specimens of this from the range. Judging from its general distribution it should be found on the higher mountains of the Catskills and perhaps in the Pocono region. Has it been seen in either of these localities?