January, 1922 



GROWTH OF TREE SEEDLINGS AND WHEAT 



79 



plant turning upward. The length of the roots on September 13 is given in 

 Table 4. 



Table 4. Root growth on heavily limed soils 



In one case the roots of 6 Jack pines growing on the limed sand had joined 

 and, for a length of 4 millimeters from the end, were closely intertwined as 

 though forming a single root-tip. The intertwined tips appeared healthy, the 

 rest of the roots brown and shriveled, with perhaps 10 millimeters above 

 ground. The seedlings were all living. Is this an example of mutual benefit 

 through protection afforded by root excretions acting on the alkalinity of 

 the soil ? 



At the end of the season the green weight of the plants was very much 

 less on the limed than on the unlimed soils; the weight on the limed humus 

 exceeded that on the limed sand by only a comparatively narrow margin. The 

 weights per plant are given in Table 5. 



* Younger than on other soils. 



Although all the trees except cedar suffered severely, the Jack pine seemed 

 to suffer a little less than the others. A certain number of Jack pines pulled 

 through on all soils, though only 6 survived on the humus. 



Curiously enough, wheat on alkaline soils suffered very little as compared 

 with trees. On the limed sand and mixture of sand and humus the height 



