57 



frustum of a paraboloid, and the top as a cone. By counting 

 back on the annual rings, and measuring the diameter at 

 every tenth ring, we can obtain the cubical contents of the 

 tree as it was ten years, twenty years, ago, and so on back 

 until it was in the neighborhood of ten years old. The trees 

 growing in what is described as rich lowland show the most 

 rapid growth in volume, although those described as coming 

 from upland pasture are not far behind. It is quite probable 

 that the latter trees were growing under somewhat more 

 crowded conditions, and did not have quite as much oppor- 

 tunity to develop their diameter growth to its fullest capacity. 

 That they were more crowded is indicated by the fact that 

 the tables on height growth show a slightly higher rate for 

 the upland pasture trees. The rate of growth for trees on 

 sandy soil is very much slower than that for the other two 

 types, being not much over 50 per cent the rate of the low- 

 land type. This seems to refute the prevailing idea that soil 

 and moisture conditions have very little effect on the growth 

 of pines. In this connection it is interesting to note that 

 the rate of growth of pines in wet swamp is the lowest of all,, 

 indicating that too much water retards the growth of pines 

 even more than too little. 



The tables of height growth follow the same general lines as 

 those for volume growth, except that, as stated above, upland 

 pasture slightly exceeds that of rich lowland. The rate for 

 the favorable sites (upland pasture and lowland) exceeds 

 that of the less favorable sites by 20 or 25 per cent, a differ- 

 ence in rate somewhat less than that of the volume growth. 



