1921] DACHNOWSKI—PEAT DEPOSITS 83 
~of tamarack. In the partially wooded portion grow heaths such 
as Cassandra (Chamaedaphne) sp., Vaccinium corymbosum, and 
others, while the ground cover consists largely of sphagnum mosses 
with the cranberry and similar plants characteristic of sphagnum 
bogs. The southern portion of this tract is under cultivation. 
Turning to the Canton peat deposit, it is interesting to note 
that the middle forest layer is wanting in this deep basin. The 
type of peat material of the period contemporaneous with the Kent 
middle forest layer consists of fibrous and relatively coarse plant 
remains from sedges and to some extent from reeds. The quantity 
of water must have diminished independently of the local alter- 
ations in the water table, for layers of a fibrous texture accumulate 
only under moderately moist conditions. The overlying peat 
stratum, on the other hand, is formed from Hypnum mosses and 
sedges, and has an admixture of macerated débris, clearly showing 
the advent of a cool period. 
The succeeding layers in the Canton deposit show a gradual 
elimination of the Hypnum mosses as a peat forming component, 
and they also indicate a return of atmospheric conditions swinging 
toward a warmer climate. Before its cultivation the Canton area 
is reported to have been a marsh with the margins partly forested. 
Thus the uppermost layers of peat in the two deposits seem to 
show that during their later history, from the last glacial substage 
(the Port Huron time and the Lake Champlain period) to the 
present, the amelioration of climate has been relatively more 
steady than at any time since the culmination of the Wisconsin 
period. The lack of structural diversity is related probably to the 
distance of these deposits from the direct influence of the later 
glacial substages. 
he beginning of the Mantua peat deposit (fig. 12), it is reason- 
able to infer, dates from the period of accumulation of Hypnum 
mosses in the Canton peat deposit and the submergence of the 
forest layer in the Kent deposit. In the Mantua deposit the 
uppermost layers similarly point to the supplanting of a cool by 
a more temperate period of climatic conditions, and to the migration 
"of plants as an essential process in the sequence of peat materials. 
It is worth noting that the forest layer has the stumps of tamarack 
