142 BOTANICAL GAZETTE [aucusr 
That the response to toxic bodies when present in small amounts ~ 
may lead to acceleration of growth has become evident also in con- 
nection with a biometric study on the annual wood-increment in 
Acer rubrum (5). Measurements upon such trees from the outermost 
edge of the maple-alder zone as were nearly the same in size, age, 
concentric growth of wood, and general environment, as similar 
forms found in woodlots near the shore gave the following differences 
in the frequencies of rings: 
Width of rings in mm........ . af X | 4.5} 2 >| 2.8) 313-5 4 ae 
Frequencies in bog-habitat.......| 16 | 10 | 23 | 20 | 27 | 12 | 20| 5| 7] 5 
Frequencies in woodlots ......... 20402) 35 19 
Width of rings in mm............ 6|.6.5| 7 | 7.5} 8 | 8.5] 9 | 9-5) 2 
Frequencies in bog-habitat........ s|-s | 6| 2} 24 Of eee 
Frequencies in woodlots.......... 
The mode and the variation constants derived from them are equally 
interesting: 
PIB UGE: oe tbat Seas rae are Bog Woodlots 
MOGs Seis ois eS et ee eee 3mm 2mm 
Meanin Si hors ee ee 3.425+0.098 1. 701+0.038 
Standard deviation oo 1.870+0.069 0, 566+0.027 
Coefficient of Variability... 4 - 35 ae 54.60+ 2.55 33-284 2-46 
ee 
We have here the type and the place-habit from two distinct 
edaphic conditions. The differences in the soil habitat have led to 
physiological variations which changed not only the type, but the 
variability and even the sign of the skewness. Quantity and quality 
of the wood have been affected; as products of the environment they 
are a measure of environmental conditions. 
To attempt to correlate the data with the work of previou 
on toxic action is obviously impossible. Definite knowledge of thé 
chemistry of bog water and bog soils is lacking at present. There 
are always present a great variety of chemical and biological agents, 
and products of decomposition, which may react collectively. Henc¢ 
definite conclusions cannot be based upon the results obtained aii 
The limited extent to which these experiments have been carried, giv 
no more than a suggestion of the possibilities. 
s authors 
Onto STATE UNIVERSITY 
olumbus 
