524 BOTANICAL GAZETTE [JUNE 
best included among those strange mesozoic conifers of whose structure and 
relationships so much is yet to be learned.—E. W. SINNoTT. 
The carpophore of Agaricaceae.—An investigation of the develop- 
ment of the carpophore of several species of the Agaricaceae by BEER” brings 
still further evidence supporting the now generally accepted view that the 
hymeniun of the Agaricaceae arises endogenously, and not exogenously in the 
manner first described by Hartic. As-to the relative priority of the differ- 
entiation of the pileus and the hymenial primordium, BEER finds that in Hypho- 
loma fascicularis and Clitocybe laccata the pileus is differentiated first, while in 
Armillaria mellea the hymenium is the first structure to become visible. In 
this respect Armillaria mellea agrees with A. mucida as described by FISCHER, 
and with Agaricus campestris as described by ATKINSON. These forms show 
that the generalization of Fayop, that the pileus is first differentiated in all 
cases, does not hold for all forms.—H. HassELBRING. 
A paper atmometer.—In an effort to obtain an instrument for the 
measurement of evaporation with temperature relations comparable to those 
of the foliage leaf, Livincston” has devised a paper cup atmometer, which is 
a modification of the Piche instrument. The advantages claimed for the new 
device are that as it contains a much smaller volume of water than the porous 
cup atmometer, it responds more promptly to changes in the external tempera- 
ture. The surface of the paper cup may also be colored and the atmometer 
used for the measurement of light effects. This form of atmometer is likely to 
prove most useful in exact laboratory and controlled experiments, but will not 
replace the more durable clay cup for ecological field studies—Gero. D. FULLER. 
Composition of soil water and plant distribution.— The percentage of 
calcium and magnesium salts in solution in the soil water is believed by LAN- 
GERON?3 to give adequate explanation for many local peculiarities of plant 
distribution. To facilitate such studies he describes methods of water analysis 
which may be used in the field and laboratory, giving, with a minimum ex- 
penditure of time and effort, results sufficiently accurate to be related to differ- 
ences in the composition of various plant associations. He has obtained 
promising results by applying his reg to the study of the bryophyte flora of 
the Bouche d’Erquy.—Geo. D. FULLE 
2t BEER, R., Notes on the development of the carpophore of some Agaricaceae. 
Ann. Botany 25:683-689. pl. r. 1911. 
22 1vincston, B. E., Paper atmometers for studies in evaporation. Plant 
World 14: 281-289. 1 
23 LANGERON, esses Valeur de ’hydrotimétrie en géographie botanique pour 
V’étude des accidents locaux. Bull. Soc. Bot. France 58: 236-245, 266-273, 327-336, 
421-428. IgIt. 
