Igri] DACHNOWSKI—CRANBERRY ISLAND 33 
The sphagnum-cranberry formation is not to be regarded as 
an intercalation (18). The organic matter deposited by past 
generations of plants shows that sphagnums, cranberry, and their 
associates occupied this surface long before the maple-alder zone 
was formed. It is therefore an earlier and normal stage of suc- 
cession, under conditions of development and a combination of 
factors which favored persistence and succession in that direction, 
and which are not suitable even today for the ecesis of a shrub- 
formation or for germination and growth of the seeds blown over 
in great quantities from the woodlots and fields surrounding the 
lake. 
The vegetation in the central zone agrees very largely with 
plant societies in bogs and swamps of more northern regions. 
Many other ‘‘boreal”’ plants which were no doubt concerned in 
the early developmental stages of the local bog are now extinct. 
This is especially true of the pitcher plant (Sarracenia purpurea), 
the creeping snowberry (Chiogenes hispidula), wild rosemary 
(Andromeda polifolia), leather leaf (Chamaedaphne calyculata), 
labrador tea (Ledum groenlandicum), pale laurel (Kalmia polifolia), 
and larix (Larix laricina). The plants are still found in Ohio bogs 
north of here. A number of them have been recently transplanted 
and are now on the island in good condition. 
Ouro STATE UNIVERSITY 
CoLumBuS, OHTO 
