1905] LIVINGSTON—PROPERTIES OF BOG WATER 351 
a priori, to either of two sets of factors, the osmotic pressure of 
the solution or the chemical nature of the solutes. Since the experi- 
ments were carried on at room temperature, it is unnecessary to con- 
sider low temperature as a possible stimulus. 
In the work on the influence of osmotic pressure upon this plant 
it was found (2, 3) that there is no tendency to form palmella till a 
pressure of about 1618.6™™ of mercury has been attained. Filaments 
still persist at a pressure of 3237.1™™, but have practically all dis- 
appeared at a pressure of 6474.2™™. But no swamp water studied 
has a pressure at all approaching the lower limit for even the incipient 
Fic. 1. Stigeoclonium filaments in Lake Michigan water. 
Fic. 2. Stigeoclonium, palmella form from filaments, in water from West Lake, 
Ann Arbor, Michigan, sample A. 
Fic. 3. As fig. 2, but in water from First Sister Lake, Ann Arbor, sample B. 
formation of palmella. Therefore, we are forced to the conclusion 
that the palmella response in these bog waters is due to the chemical 
nature of the solutes. The plant grows well as filaments for a long 
time in distilled water, so that it is impossible to relate the reasons . 
to absence of inorganic salts. 
Definite knowledge of the chemistry of bog water is beyond our 
reach at present. It appears that all bogs are acid to some degree, 
and there has been a tendency for many authors, e. ., SCHIMPER 
(7, Pp. 4, 8, 657, etc.), to attribute the peculiarities of bog plants to 
this Property. In the author’s study of chemical stimulation (5) it 
was found that nitric and sulfuric acids produce palmella at concen- 
trations of from o.coorm to o.c0006n. The natural swamp waters are 
uniformly more acid than this; therefore, were the acid property 
of the latter due to either of these mineral acids, we should expect 
all of these waters to produce the palmella response. This is obviously 
