357 
or quite to Deuel County. It occurs, also, in isolated cafions in 
the central counties (in the Loup River Valley) and thence fifty 
or sixty miles eastward. Recently some remains of a considerable 
grove of pines was discovered along the bluffs of the Republican 
River, in Franklin County, about fifty miles east of the 1ooth me- 
ridian. 
Mr. Cowell exhibited specimens of hybrid and double-flowered 
sunflowers, Helianthus decapetalus X H. petiolaris and H. lenticu- 
darts, 
Tuurspay, AucusT 26TH. Mornin. 
Prof. Bessey remarked on the cafion flora of the plains. On 
the Great Plains there are two nearly distinct floras, viz: (a) that 
of the general surface, which, as we pass westward, is more and 
more like that of the arid regions, and (4) that of the river valleys 
and cafions, in which are found trees, shrubs and herbs which have 
invaded this dry region from the east and west. The line of de- 
markation between the cafion flora and that of the general surface 
is often very sharp, the one giving way to the other within the 
Space of a yard or less. 
Dr. E. B. Copeland discussed turgor-variations in the mosses. 
He stated that turgor is higher in the mosses than in most other 
plants, and exceedingly variable. Tests were made on various 
Species, especially Mnium cuspidatum and Funaria hygrometrica at 
temperatures varying from 0°-34° Centigrade, the turgor being 
determined by plasmolysis in solutions of potassium nitrate. 
From near zero up to 20°C. there was a decided decrease of turgor 
with increase of heat. This variation is due to chemical changes 
in loco, but seems to be unaccompanied by any change in the 
Starch or sugar present. In Mnium, however, it is dependent on 
the presence of not very remote products of assimilation. This 
adjustment of the concentration of the cell sap is of manifest ad- 
vantage in resisting variations of temperature. 
Dr. A. P. Anderson described a simple apparatus for spraying 
plants, consisting of two tubes at right angles to each other, similar 
to the one used by artists for spraying crayon drawings. 
Mr. E. J. Durand described the structure of pseudo-parenchyma 
in the higher fungi. In most of the higher fungi there is a tissue _ 
