DACHNOWSKI: BOG VEGETATION AND PEAT SOILS 61 
several investigators, peat soils contain bacteria inducing diastatic, 
_ inverting, proteolytic, cytohydrolytic, and reducing actions during 
the digestion of the plant debris in the upper layer of the peat 
substratum. A marked interdependence was shown to exist be- 
tween the organisms; and the fact that many organisms are 
obligate saprophytes capable of growing only on a substratum 
similar in composition to the character of the respective plant 
association, is indicative of a close relation between a specific 
bacterial flora, the progressive disintegration of organic material, 
and the successions of vegetation in bogs and peat deposits. The 
characteristic xerophily of ancient* and modern bogs the writer 
attributes to the edaphic adversities encountered rather than to 
climatic differences. Though the biological processes in the soil 
thus appear to be more essential than the quantity of mineral 
components, there yet remains the question how far microorgan- 
isms are active in the change of vegetable matter to peat and 
lignite, and in the formation of gases and of coal. To what extent 
is the cooperation either essential, useful, or dangerous in the 
formation and character of organic compounds available for 
assimilation? What are the factors affecting and limiting the 
decomposition of organic matter? 
What is the nutritive value of the different carbon and nitrogen 
compounds arising through the activity of microorganisms? 
Toxic substances possess an unlike physiological value to different 
plants and hence it is but one step further to raise the question of 
the comparative nutrient value of these organic compounds.t 
More recent experiments with isolated bog bacteria show very 
clearly the ability of a number of the organisms to increase the 
amount of assimilable compounds in peat soils. The transpiration 
values of these cultures for wheat plants lie 200 per cent above 
that of the control. The fact that to many plants bog toxins are 
injurious at one concentration but not at another, and that 
further dilution carries with it a corresponding intensification in 
* Dachnowski, A. The problem of soohecsodage in the vegetation of the 
Carboniferous Period. Am. Jour. Sci. IV. 32: 33-39. TOIT. 
} Haskins, H. D. The utilization of Pi in agriculture. Massachusetts Agr. 
Exp. Sta. sae 1909": 39-45. 1909. 
Lipman, F. G. Report of the Soil Chemist and Bacteriologist of the New 
Jersey he Hats: Sta. 188-195. 1910 
