STATISTK'S AND CONCLUSIONS. 



23 



b«^hind for the next twenty-five to tliirty yesirs, then jnoceeds iit ahonf tlie same i;ite, but p(;rsistiiig 

 longer thiin the Loblolly. At the iige of fifty years tlie Oul):iii I'ine witli 4(i cubic feet has made 

 nearly twice the amount of the Loblolly and more than four times that of the Longleaf, but at oue 

 hundred years the difference is reduced, being then 115, 00, and .■>.") cubic feet, respectively, for the 

 three si>ecies. 



Both Loblolly and Shortleaf Pine reach their maximum growth sooner than the other two 

 species. While these still show a jiersistently ascending line at one hundred and twenty to one 

 hundred and forty years, the rate of growth in the Loblolly shows a decline after tli(^ one hundredth 

 year, and the Shortleaf has done its best by the eightieth year. These facts give indications as to 

 the rotation under which these various species may be managed. 



Fig. 6 Diagram 8bowin<i; comparative progress of diameter growtli in average trees. 



As stated before, the growtli of trees, especially in the virgin forest, is quite variable even for 

 the same species and same soil conditions; an average, therefore, like the one presented in the 

 diagrams, however perfect, could apply only when largo numbers are considered. Thus there are 

 fast-growing trees of Longleaf and slow-growing of Cuban or Loblolly Pine. A'et the diagrams 

 will fairly well represent the average growth, with the possible exception of the Cuban Pine, for 

 which the number of measurements was too small to furnish reliable data. 



STATISTICS AND CONCLUSIONS. 



The greatest difficulty Dr. Mohr has found is in the statistical portions of his work. To detcr^ 

 mine the amounts of remaining timber supplies of the various species is almost an impossibility 

 without a very elaborate and laborious canvass, which, to be sure, it would appear our duty to 



