66 BOTANICAL GAZETTE [AUGUST 
of their greater age, the deposits of the earlier morainic fields 
constitute climatic indicators of the greatest interest, and they 
should not only furnish additional data, but also serve as a check 
upon any evidence which the peat deposits in the later morainic 
areas may contribute. 
The material here presented is only of preliminary import. It 
has emerged in the field work of the past seven years, and hence 
a definite correlation is impossible as yet, partly because too little 
is known of the extent and intensity of the changes. The chief 
difficulty, however, lies in the fact that much along the line of 
detailed field and laboratory studies has still to be accumulated. 
The conclusion is irresistible, however, that when the field is 
traversed the peat deposits will be found to furnish a new great 
record of the vegetational and climatic oo: of the country 
since Pleistocene times. 
GENERAL STRATIGRAPHIC FEATURES IN WATER-LAID 
PEAT DEPOSITS 
The question of the formation of lacustrine peat deposits has 
‘produced a copious literature in many countries, but there is still 
a dearth of observational evidence on their actual structural origin. 
Hardly a case exists of an intensive study in which conclusive proof 
is available showing the types of peat material in process of forma- 
tion. This does not mean that the process may not be as is gener- 
ally assumed, but it does indicate that even a well-nigh universal 
opinion may yet constitute merely an excellent working hypothesis. 
It can be accepted definitely only after more rigorous tests and 
extensive field work disclose a clearly defined basis. This account 
merely serves to emphasize what may be regarded as a general 
view of the development and structure of lacustrine peat deposits. 
Although this has been discussed at some length.in various papers 
already published, a brief outline is presented here in order to 
connect it with the profile sections of the peat deposits on which 
these discussions have a bearing. The cross-sections which follow 
have been selected from American and European peat deposits 
largely on account of their stratigraphic relationship. They visu- 
alize the succession of strata in water-laid deposits, and illus- 
