1916] FORSAITH—ALLOCTHONOUS PEAT 49 
1914, at a time when the water was at a low level), which accounts 
for the absence of any peat deposits, except in sheltered bayous, 
where the action of the waves has had no opportunity of prohibiting 
the accumulation of plant débris. Many of the sheltered portions, 
also, present no material of an organic nature, since the shallow 
character of the lake and the large fluctuation of the water level 
cause them to be dry for a part of the year, at which time the 
amassed material becomes desiccated and oxidized and floats away 
at the next inundation. 
The only region where peat was collected at Tohopikaliga was 
in a sheltered bay formed by the broadening of the inflowing 
creek (diagram, 60-65), where there appears a very shallow layer 
of sandy, drifted, sedimentary, and wind-blown allocthonous peat. 
Thus it is very evident that this lake presents conditions very 
similar to those found in the small shallow lakes previously men- 
tioned, in that the bottom is sandy and there is a general absence 
of vegetable accumulations. 
At Pablo Creek, Duval County, there is a broad marsh with 
an area of over 4,000 acres, entirely covered by a uniformly bluish 
black peat to the depth of ro feet. This deposit evidently owes its 
existence to the accumulation of river drift and wind-blown mate- 
rial, in addition to the constant amassing of fallen herbaceous 
plants. The first 8 feet present a series of samples of a bluish 
color, in which there appears no coarse material. One very notice- 
able feature in this locality is a strong sulphurous odor, which may 
be due to the presence of an abundance of Beggiatoa. Below this 
fine plastic mass there is a thin stratum of woody material, prob- 
ably representative of an ancient inundated forest, which must 
have grown at some time when the water was at a much lower 
level than it is at present, and on its subsequent rising this flora 
gave place to more herbaceous and more water-loving species. 
The very basal layer consists of a shallow deposit of fine lacustrine 
peat, which has been formed upon the blue clay floor of this ancient 
lake. The material from this region is now used for agricultural 
Purposes, after it has been artificially dried and mixed with com- 
mercial fertilizers, and the composition thus formed is placed on 
the market as “prepared humus,” which should be very valuable 
