52 BOTANICAL GAZETTE [JULY 
wind-blown, and sedimentary vegetable material in permanent, 
open, and quiet bodies of water (allocthonous), and those which 
have resulted from a gradual accumulation of successive genera- 
tions of plants im situ, in the presence of more or less permanent 
but concealed water (autochthonous). 
2. Allocthonous peat is characteristic of deep permanent lakes 
and the lower portions of marshes; autochthonous peat is charac- 
teristic of the upper portions of marshes, the upper strata of filled 
lakes, and swamps. 
3. From what studies it was possible to make in regard to the 
average extent of these two types of peat formation it is evident 
that those of a lacustrine character (allocthonous) are of vastly 
greater numerical and quantitative importance than those of an 
autochthonous nature. 
In conclusion, the writer wishes to express his most sincere 
thanks to Dr. C. A. Davis, of the Bureau of Mines, Washington, 
D.C., for very valuable advice in regard to the collection of peat, 
for a report on the uses of peat (1), and for letters of introduction; 
to Mr. O. F. BurceEr, of the Bussey Institute of Harvard Univer- 
sity, for letters of introduction to many of his friends in Florida; to 
Mrs. N. M. G. PrancE, of Jacksonville, Florida, for valuable in- 
formation in regard to the work; to Professor P. H. Rorrs, Director 
of the State Experiment Station at Gainesville, for information in 
regard to the locations of peat deposits. To Dr. E. C. JEFFrrey, of 
Harvard University, I wish to express sincere thanks for advice. 
HARVARD UNIVERSITY 
LITERATURE CITED 
1. Davis, C. A., The uses of peat for fuel and other Se _— Interior, 
Bur. Mines Bull. no. 16. 1911. pp. 7-74 and m 
, The origin of coal. Dept. Interior, Hu Mines Bull, no. 16. 1913. 
pp. sbor86, 
Harper, R. M., Preliminary report on the peat deposits of Florida. Fla. 
State Geol. Survey. 1910. pp. 197-375. 
. Matson, G. C., and SanForp, S., Geology and ground waters of Florida. 
U.S. Geol. Survey no. 319. 1913. p. 17 and map. 
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