14 BOTANICAL GAZETTE [JULY 
The bog water is relatively clear, the suspended particles 
imparting to it a slight tinge of olive green to brown. The analy- 
sis of samples of bog water and lake water give the following 
results (table III). 
TABLE III 
CHEMICAL ANALYSIS OF BOG WATER AND LAKE WATER FROM CRANBERRY ISLAND 
Constituents i " B cynic per = . Bog water, central zone 
(May 30, Igto) (cranberry-sphagnum) Lake water 
Nitrogen as albuminoid ammonia........ 10.34 4.50 
Nitrogen as free ammonia. ...........:.. 5-19 2.95 
eererogent WS TEER. cc es es 0.0005 ©.0000 
Ni Se WS NIALES oe i eS 0.20 °.10 
ete eee ee Oa 0.30 1.00 
PeQUIEGd OLY GER. oe ee ee 71.80 3.490 
Alkalinity, rob CaCO.) ee ee a 30.00 75.00 
In ieiparcid ae) es 74.00 76.00 
Aetab BOUCSSe e  eoy ye  h s 140.00 200.00 
Loss on naeenhey Sore eo ek ey aay us Gee 100.00 4.00 
Examining these results, shown in table III, we find that 
the lake water contains organic matter in a state of advanced 
decomposition. This is indicated by the relatively high free 
ammonia, and the small amount of oxygen consumed. The 
reverse holds true for bog water from the sphagnum-cranberry 
zone. In other points lake water agrees well with bog water. 
The osmotic pressure and the acidity have been found to be the 
same for both stations. As compared with the freezing point 
of pure distilled water, the average lowering in the various deter- 
minations is o°007 and o°009 for the central station and the 
maple-alder and lake station respectively. Acidity varies from 
less than 0.00075 to 0.0038 normal acid when titrated with a 
n/o.o5 NaOH solution. The soil is alkaline at depths near the 
marly subsoil. The stress laid by various authors upon the re- 
lation of these two factors to plant societies in bogs, in so far at 
least as this region is concerned, will not hold. They are not 
factors in the selection or distribution of species for bog habitats. 
Physiological properties of bog water 
The physical and chemical sides are found unsatisfactory to 
explain the functional variations and the pathological changes 
