1905] LIVINGSTON—PROPERTIES OF BOG WATER 355 
2. The responses of this alga to bog water and to cold are as nearly 
identical with those obtained by TraNnsEAu with Rumex, for the 
same conditions, as the nature of the two plants would permit. 
3. The active Se neeauEte are not directly related to the acidity 
of the water. 
4. Boiling the water decreases its acidity but does not appreciably 
affect its action as a stimulating agent. 
5- The stimulating substances are most markedly present in water 
from those swamps whose vegetation is most definitely of the bog 
type. They are absent from river swamps and large lakes; in water 
from swamps whose vegetation is of a character intermediate between 
those of the river swamp and the bog, they are present to some degree, 
their amount being roughly proportional to the extent of the xerophi- 
lous character of the vegetation. 
6. The stimulating substances here demonstrated may play an 
important réle in the inhibition from bogs of plants other than those 
of xerophilous habit. 
THE UNIversity oF CHICAGO. 
LITERATURE CITED. 
I. eee B. E., Physical properties of bog water. Bot. GAZETTE 37: 383- 
385. 1904. 
, On the nature of the mua which causes the change of form in 
polymorphic green algae. Bor. GAZETTE 30:289-317. 1900 
, Further notes on the elbeii of polymorphism in green algae. 
Bor. GAZETTE 32:292- gol. 
, The réle of diffusion we osmotic pressure in plants. Chicago. 1903. 
The last chapter of this monograph was reprinted as “The effect of the 
osmotic pressure of the medium upon the growth and reproduction of 
organisms.” Chica 
5- ———,, Chemical euitae of green algae. Bull. Torr. Bot. Club 32:1-34. 
figs. 17. 1995. 
, Notes on the physiology of Stigeoclonium. Bor. GAZETTE 39:297- 
300. figs. 3. 1905. 
7. Scurprr, A. F. W. Plant geography upon a physiological basis. Translated 
by W. R. FisHEer. Oxford. 1903. 
8. TransEav, E. N., On the development of palisade tissue and resinous deposits 
in leaves. Scienan Bt S. 19:866-867. 1904. 
