iqS botanical gazette [march 



rules of growth for the species. Inasmuch as a description of all 

 the trees used would be confusing, short silvicultural notes on each 

 specimen will be given in the text where' it seems necessary. 



Previous investigations of growth in forest trees 



Before entering upon a description of the methods employed in 

 this work, a brief resume of those of other investigators will perhaps 

 add interest to the present study. 



Von Mohl (25) sought to determine the growth of trees by 

 making measurements of the circumference at a definite place on 

 the bole. From these the radius was computed and the increase 

 in thickness noted. Christison (5) pursued the same method and 

 computed data for a large number of species, including both hard 

 and soft woods. The data of Jost (13) were based in part on the 

 methods given above and in part on measurements which he 

 obtained by the use of a "Fuhlhebel."^ Any data secured through 

 bark measurement are unreliable because of continual changes 

 going on in the older parts of the secondary cortex and changes 

 which bear no relation to the newly forming rings. As a result, 

 only broad generalizations can be drawn from data based on such 

 methods. 



T. Hartig (12) sought to determine the growth of tree species 

 in a different manner. Choosing even-aged, pure stands, where 

 growth conditions appeared to be similar, he felled typical speci- 

 mens from these at different periods and made comparative studies. 

 He assumed that in such^tands all individuals exhibited similar 

 characteristics of growth, a view that is untenable in the light of 

 our present knowledge. Hartig' s method is open to criticism 

 in that it was extremely inaccurate and could therefore never give 

 reUable results. ' Growth varies markedly not only in different 

 individuals in a stand, but also in different parts of the ring at a 

 given height. 



MiscHKE (24) took the first steps in the direction of securing 

 accurate results. Using an increment borer, he studied the annual 

 ring at different periods in its development and obtained in this 

 way the first results which were in any way accurate. Wieler (39) 



' For description see reference. 



