THE SOILS OF FLORIDA. 
75 
where the vegetation is dense, some organic matter accumulates. 
Passing beneath the surface the soil as a rule becomes ochre yellow. 
Somewhat extensive areas of scrub lands are found in central 
peninsular Florida. It is frequently associated with, but not con¬ 
fined to, the lake region type of topography. The scrub is well- 
drained, since the rainfall passes at once into the sand. Sandy pine 
lands frequently give place to scrub without any apparent change 
in soil, topography or drainage conditions. 
The present vegetation of the scrub has probably replaced an 
earlier growth of pine. This process of replacement of pine forests 
by the sand-loving species may be observed in many localities. The 
deciduous oaks are first to obtain a foothold among the pines. These 
in turn give place to the evergreen oaks, which seem to predominate 
in the scrub. 
PRAIRIE AND SAVANNA. 
The terms prairie and savanna are applied to lands that are level 
and devoid of trees or nearly so. The prairies as a rule are better 
drained than the savannas, although many of the prairies that are 
entirely dry during the dry season are more or less flooded during 
the season of summer rains. The soil of the different prairies is 
so variable as scarcely to admit of a generalized description. Clay 
soils and sandy soils are included as well as dark and light colored 
soils. Many of the prairies that are dry during a considerable part 
of the year have light sandy soils, the organic matter having been 
oxidized. Those prairies that are partly flooded retain proportion¬ 
ately more of the organic matter which gives the soil a dark color. 
A few of the large prairies or savannas were described in the Third 
Annual Report, pp. 43-76, 1910. 
MARSH AND MUCK LANDS. - 
When land is overflowed during all or nearly all of the year, the 
growth of vegetation falls beneath the water, is protected from de¬ 
cay and accumulates to form muck. W T ken drained the muck lands 
make fertile soils. The muck lands may or may not support a tim¬ 
ber growth. 
The term marsh is applied to overflowed lands devoid of timber 
but supporting a heavy growth of coarse grass. Marshes may be 
of salt or fresh water. The salt or marine marshes are found bor¬ 
dering the coast and have been built up by the tide. They consist 
largely of silt, mud and clay with an admixture of organic matter 
