394 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT. 



by personal observation. For example, in Wakulla County probably most of 

 the tilled land is in region 13, which covers less than one-fourth of the county, 

 and practically no fertilizer is used there (see p. 296) ; but about half the county 

 is in region 9, where fertilizer is used at the rate of about a dollar's worth per 

 acre per year. So instead of the flatwoods part of the county having half the 

 tilled land and using half the fertilizer, it probably has something like one-tenth 

 of the tilled land and uses nine-tenths of the fertilizer. Third, economic con- 

 ditions sometimes cause the use of much more fertilizer than the ordinary sta- 

 ple crops would naturally require, as in Gadsden County, where large areas are 

 devoted to tobacco, which requires a great deal of potash, and in the neighbor- 

 hood of cities and along trunk lines of railroad, where truck-farming is carried 

 on extensively. 



The first column of figures in the table is for areas, in square miles, and 

 the next three for the percentages of evergreens, Ericaceae (among the shrubs) 

 and Leguminosae (among the herbs), most of which have already been given 

 in the regional descriptions. The fifth is for the percentage of original forest 

 remaining, which is of course a little less than the difference between that of 

 improved land and 100%. The sixth column represents the amount expended in 

 1909 for fertilizer, per acre of improved land, according to the 13th U. S. census. 

 The seventh is for density of population (number of inhabitants per square 

 mile), and the last for the percentage of whites. (The cities of Pensacola and 

 Jacksonville are excluded from the calculations of density of population, for the 

 reasons given on pages 229 and 336.) It did not seem worth while to insert in 

 this table the rates of increase of population, which have been mentioned in 

 some of the regional descriptions, for although they differ greatly in different 

 regions, they vary too much from one decade to another to have much geo- 

 graphical significance. 



All the figures of course are only approximate, but in the first five columns 

 the average error is probably not more than 10% one way or another. The last 

 three columns are less reliable, on account of the lack of minute detail in the 

 census reports, as already explained; but the averages for the whole of north- 

 ern Florida, at the bottom of these columns, are just as accurate as the work 

 of the census enumerators, if not more so. In some of the columns figures un- 

 known but believed to be above the average for northern Florida in that par- 

 ticular thing are indicated by 4- and the reverse by — , somewhat as was done 

 in the plant lists. Where no such guess can be safely made an interrogation 

 point is used. 



