194 FLORIDA GEOLOGICAL SURVEY I3TH ANNUAL REPORT 



right in the phosphate country, is not surprising, but the still higher 

 figures for R, T, and U are not so easy to explain. Veryl likely 

 in each of these cases, however, the phosphorus is mostly combined 

 with iron, as ferric phosphate, which is almost insoluble.* 



There is nothing in the analyses of the two soils from Long 

 Key (samples O and P) to indicate extreme sterility, and yet no at- 

 tempt seems to be made to cultivate them, and the woody plants 

 there are all evergreen. 



Sample O, from a sandy hammock, is deficient in nearly every- 

 thing, and its vegetation is nearly all evergreen. In everything ex- 

 cept potash its analysis resembles that for C about as closely as two 

 samples from different counties and regions collected by differ- 

 ent people about 35 years apart could be expected to; and the dif- 

 ference in potash illustrates the difference between the Hilgard and 

 A. O. A. C. methods in that respect. 



Sample R represents one of the richest upland soils in Florida. 

 S is not very different from O, but the differences are all in the di- 

 rection that the vegetation indicates. T and U are rich calcareous 

 soils, well supplied with potash and phosphorus also. 



The analyses make V a better soil than W in almost every re- 

 spect, though the vegetation indicates decidedly otherwise ; a para- 

 dox for which no adequate explanation can be given at present. 



X is a rich soil, and Y and Z are poor. 



• CLIMATE 



The climate of central Florida differs from that of northern 

 Florida, and still more from other parts of the eastern United 

 States, in being warmer in winter and wetter in summer, especially 

 late summer. The following table of climatic data for a number of 

 stations in the area is compiled mostly from Bulletin W (Sections 

 83 and 84) of the U. S. Weather Bureau, and the annual climato- 

 logical summary of the Florida section of the same Bureau for 191 3. 

 The data given are the average temperature for January, July and 

 the whole year, in degrees Fahrenheit, the average length of the 

 growing season (period between killing frosts), in days, the av- 

 erage annual rainfall, in inches, the percentage of the total rainfall 

 that comes in the four warmest months (June to September) and 



*See Hilgard, Soils, p. 356. 



