1911] DACHNOWSKI—CRANBERRY ISLAND T5 
in structure which agricultural plants undergo when growing in 
peat and bog water. Elsewhere it was shown by means of tran- 
spiration data of cultivated plants, and with a biometric study on 
the annual wood-increment in the red maple found on the island 
and in woodlots near the shore, that (1) a difference exists between 
different species in their power of resistance to the toxic action of 
the substratum; (2) the contrasts in the relative growth of plants 
vary with the substrata of the several bog plant formations; 
(3) the toxic principles whether enzymes or other bodies are not 
found in bog water when attempts are made to extract them with 
insoluble adsorbing bodies; they do not pass readily through fil- 
ters and only slightly through filter paper; (4) different physiologi- 
cal phases result from the progressive addition of an adsorbing 
substance; (5) agricultural soils used as filters decrease con- 
siderably the normal physiological activity of plants growing in 
them; (6) the reduced absorptive capacity of the plants is not a 
consequence of the absence of root hairs, or of a smaller absorbing 
surface. 
The bacterial flora of the peat substratum 
Present writers seem to hold the view that among the simplest 
of fungi, the Schizomycetes, few are present in peat bogs, and that 
only a small number of species, included in perhaps only one 
family, are at all injurious to higher plants. Examination has 
shown that peat soils contain unsuspected groups of bacteria, 
which in number and efficiency vary during the seasons and with 
the several plant zones on the island. As a means of differentia- 
tion between the bacterial flora of the plant formations, studies 
were made on the action of the bacteria in 0.5 cc. bog water upon 
various culture media in fermentation tubes. Soil water solutions 
were collected in sterilized glass-stoppered bottles from each of 
the following stations: station I, lake water; station II, marginal 
zone (Decodon-Typha-Hibiscus); station III, cranberry-sphag- 
num zone, 1-3 feet; station IV, same, 3-5 feet below surface 
vegetation; station V, maple-alder zone, 1-3 feet; station VI, 
same, 3-5 feet below surface vegetation; station VII, tamarack 
soil from Edgerton, Ohio; station VIII, peat soil under cultiva- 
