121 



to a large part of the glaciated region of uortheru and northwestern Indi- 

 ana. Of course the immediate valleys and terraces of rivers and streams 

 furnish special conditions which must be considered as exceptional. It is 

 probable that any extended study of the rate of growth of the species dis- 

 cussed in the region indicated will show results but slightly varying from 

 those given above. 



9. It is lu'ol.ablo that undei- soil conditions such as those described, 

 larger forms than those found today but rarely occurred. A careful exam- 

 ination over wide areas foi" old stumps of the virgin forest, showed that 

 all of the large forms were found in alluvial soils and never by any chance 

 in the thin-soiled uplands. 



These studies are being extended to include many of our native species 

 and arrangements have been made to increase the number of forms studied 

 of the species discussed in this paper. 



The exact knowledge of the rate of growth of various species under 

 differing conditions is a matter of vital importance from the viewpoint of 

 wood-lot forestry. It is scarcely less far reaching in its application and of 

 scarcely less economic signilicance than a knowledge of forest utilization. 

 If the conclusions here presented are warranted by the date very self-evi- 

 dent practical application necessarily follow. These, however, are not in- 

 cluded in the scope of this paper, but will be presented later. 



