208 BOTANICAL GAZETTE [MARCH 
NOTES FOR STUDENTS. 
EBERHARDT‘ has performed a series of experiments with a view to find- 
ing the influence of dry and humid air on plant structures. These experi- 
ments in general confirm the work of Kohl and others. Humid air causes an 
increase in the length of the stem and the size of the leaf surface, while there 
is a decrease in the stem diameter, the amount of chlorophyll, and the root 
development. Dry air increases the thickness of the cuticle, the number of 
stomata, the woody tissue, the sclerenchyma, and the palisades.— H. C. 
COWLEs. 
E INTERESTING STUDIES have been made by Nestler5 upon the well- 
by testing the effect upon him The hairs of Primula Sinensts act in a 
similar w t the poisonous effects are much less marked.— 
COWL 
R. G. KLess published last year® the third paper of a series on the 
aaa of reproduction in fungi in which he brings together the previ- 
ous investigations with some hitherto unpublished researches, and seeks 
to present general considerations on the whole subject. The paper is full of 
suggestions and too valuable to mutilate by an attempt to summarize it. One 
general criticism lies against Klebs’ work and his conclusions, namely, that 
he does not take into account sufficiently the effect of changes in osmotic 
pressure to which his experimental plants are subjected with the changing 
composition. It remains to be seen whether the conclusions are not vitiated 
by this untested factor.—C. R. B 
ARNEY? discusses the Lower Austral element in the southern Appa- 
lachians. The mountains have representatives from all of Merriam’s zones 
from the Lower Austral to the Hudsonian, though the Transition zone is 
most fully represented. Austro riparian colonies are found up to 1200 feet 
along the eastern boundary of Tennessee. Kearney divides the Austral 
mountain plants into those which are probably of neotropical origin and have 
come in since the ice age, and those which have probably descended from 
the Tertiary floras of northern regions. The plants of the first group are 
chiefly xerophytic, while those of the second group are mainly ligneous 
tropophytes. Lower Austral forms must have left the mountains during the 
4Compt. Rend. 131: 193-196, 513-515. 1900. 
5 Ber. deut. bot. Gesell. 18 : 189-202, 327-331. 1900. 
Jahrb. f. Wiss. Bot. 35 : 80-203. 1900. 7 Science N. S. 12 : 830-842. 1900. 

