118 



Table IIL Juqlans nigra. 



Serial Number. 



Inches 

 Diameter. 



No. of An. 



Average 

 Yearly 

 Increase. 



are of the same age and grew on a gentle northward-facing slope in an area 

 of less than an acre, yet the diameters range from 15 to 22 inches. 



2. Conclusions as to the rate of growth of various species, which fail 

 to take into account individual variations ax"e manifestly misleading. This 

 variation may reach as much as 25 to 30 per cent, above or below the aver- 

 age growth rate. Incidentally it gives strong emphasis to the necessity of 

 great care in the selection of seeds for cultural work — since a careful se- 

 lection may increase the wood crop to the extent of 25 per cent, beyond the 

 average. 



3. The growtJi rate in the area examined was exceedingly slow, especi- 

 ally in the case of the oaks. In a report of W. F. Fox, Superintendent of 

 State Forests. New York, it is stated that a vigorous three-inch white oak 

 sapling would, under favorable conditions, at the end of twenty years at- 



