214 
Demonstration of Absorption of Carbon Dioxide and of the Genera- 
tion of Oxygen by Diatoms. By T. Chalkley Palmer. Proc. 
Acad. Nat. Sciences, Phila. F. 1897. 
This paper describes a method of demonstrating the normal 
process of carbon dioxide assimilation in diatoms. It rests upon 
a color test and is substantially as follows: A dish of suitable 
size and shape is filled with spring water tinted pale red by a solu- 
tion of haematoxylin. A glass tube is filled with this solution, its 
mouth closed with a rubber stopper in which a quill tube is in- 
serted and the whole hung over the dish so the quill tube dips 
under the surface. Carbon dioxide from the lungs is blown into 
the remainder of the water in the dish until it loses its reddish 
tint and becomes brown. Two tubes are now filled with this 
water, into one of which a few clean living diatoms are put. Both 
tubes are corked and hung in the same manner as the first. On 
exposing the apparatus to a bright light, gas rises in the tube con- 
taining the diatoms and at the same time the color of the liquid 
begins to change. In about fifteen minutes it is pale red like that 
in the first tube, the color deepens until it is blood red, showing 
that the carbon dioxide has disappeared and oxidation has taken 
place. The diatoms used for this experiment were the long fila- 
mentous forms of Eunotia, E. major of Rabenhorst.  E. L. G. 
Beitrige zur Moosflora von Nord-Amerika. Dr. Julius-Roell. Hed- 
wigia, 36: 41-66. 1897. 
This is an enumeration of several collections sent to Dr. Roell 
from Ohio,’ Michigan, Wisconsin, Indiana, Arkansas, Missouri, 
Washington, Labrador and Greenland, with four species collected 
by himself at New Durham, New Jersey. It includes long critical _ 
notes on several species of Sphagnum, especially F. Austini Sull. 
and its forms, and the following new species and varieties: 
Dicranum Miquelonense var. crispatulum, Meesia tristicha vat. : 
Purpusu; Plagwthecium Roesti Hpe. (P. Sullivantiae Sch.) vat. a 
longifolium Roell; Hypnum (Campylium) simulatum Kindb., - 
Hypnum pratense var. Purpusti Roell; Dicranum flagellare vat 
brevifolium Roell; Thutdium lignicola var. Roellii Ren. & Card. 
Hypnum arcuatum var. ramosum Roell ; Eurhynchium strigosume vat. 
sobustum Roell; Fontinalis denticulata Kindb.; Hypnum fluitans vat 
