220 BOTANICAL GAZETTE [MARCH 
from it. The young trees are largely balsams. The herbaceous 
growth is practically the same that is found in the bog forest. It 
will be noted that all the trees of the climax forest are present here, 
and that the stages are telescoped as in the bog succession. 
A locality where the climax condition had been almost attained 
was found in a narrow stream valley at the head of Brady Cove 
(Sec. 18, T. 66.N., R. 35 W.). The forest here, which fills the valley, 
is of the climax type except for an occasional ancient Thuja and a 
slight admixture of Fraxinus nigra. Fallen trunks of Thwa are 
fairly numerous. The shrubs and herbs are a mixture of swamp 
forest and climax forest species. 
That there is a general resemblance between the bog succession 
and the delta swamp succession is very evident. There are also 
some striking differences which are constant in the localities studied. 
Most important of these are the following: sedge mat not floating; 
interpolation of grass stage as the most important peat-forming 
agency; absence of sphagnum, true bog shrubs, and Picea mariana; 
dominance of Thuja in the swamp forest. 
It is conceivable that under certain circumstances one succession 
might pass over into the other. This seems to have happened at 
the head of Siskowit Bay just north of Senter Point. A large 
swampy area has been cut off from the bay by a high curving beach 
ridge 1 km. long. That there was originally a delta swamp here is 
shown by the presence of a remnant of the former stream, a winding 
strip of water ending abruptly against the outer ridge. For some 
reason, possibly on account of post-Nipissing tilting, the current of 
the stream became insufficient to keep its outlet open in opposition 
to the vigorous wave action upon the shore of the bay. The 
resulting stagnancy has brought about a partial change to bog 
conditions. The former stream is partly filled with an open growth 
of Menyanthes, Equisetum fluviatile, Utricularia intermedia, and 
Potamogeton heterophyllus. Along the water’s edge there is a band 
of nearly pure Carex filiformis, recently established. The body of 
the swamp is occupied by a sedge-grass society, in which Scirpus 
caespitosus is dominant. Accompanying species are Carex exilis 
Dewey, Muhlenbergia racemosa (Michx.) BSP, Sarracenia purpurea 
L., Vaccinium Oxycoccos L., Aster umbellatus Mill. var. pubens 
