1905] LIVINGSTON—PROPERTIES OF BOG WATER 349 
filaments are taken from the conditions which favor their growth 
and are placed in those favoring the palmella form, their cells round 
off and partially or completely separate, they begin to divide slowly 
in all planes, and the result is the typical form for these conditions. 
A return to the conditions for filaments is followed by the resumption 
of that form, partly by the growth of filaments directly from the pal- 
-mella masses, and partly by the production of zoospores which germi- 
nate to form new filaments. Zoospores are not produced in solutions 
of high pressure, and they fail to germinate in solutions which produce 
the palmella form, though they are produced in the cold and in 
Poisoned solutions. 
The waters tested in these experiments are in large part the same 
as were used in the determination of the osmotic pressure (1). The 
work was carried on partly at the New York Botanical Garden 
and partly at the University of Chicago, and extended from June 
1902 to January 1905. The cultures were made in the manner 
described for water cultures of this plant in the author’s earlier 
papers. 
Since a number of authors have loosely attributed SCHIMPER’S 
“physiological dryness” (7) of bogs to acidity, titrations of most of 
the natural waters here employed were made with n/100 KOH 
solution, using phenolphthalein as indicator.” 
Data from the experiments are given in the following table. In 
the column of responses, F—F denotes that the filamentous form 
persisted as such when placed in this particular water. F—P denotes 
that the original filaments became palmella and that no new filaments 
were produced. F—4P denotes that filaments persisted, but that 
there was also a marked production of palmella. A number of cul- 
tures were made with each of the waters, and the result is the general 
one for all. The cultures were continued for two to four weeks. 
The acidity data are given in terms of normal acid and the pressure 
in terms of millimeters of mercury at 25°C. 
From the table it is seen at once that in some of the waters the 
palmella form was produced; in others it was produced in some 
— but filaments persisted; and in still others the filamentous 
the indicators at hand this was the best, although it is —— not per- 
fect ‘3 oh acids as are probably present in these waters. 
