50 Bulletin Wisconsin Natural History Society [Vol. 12, Nos. 1 & 2 
two subspecies (of the same species) to inhabit the same region, 
they having had different sources of ingression, and dwelling in 
different associations? It seems not at all improbable that, at 
least in some instances, this might be the case. 
VI. SUMMARY 
Kidgeway Bog is of glacial origin and lies in a slightly elevated 
plateau near the source of the Wisconsin River in northern Wis- 
consin. Its biota, based upon a study of the land vertebrates and 
a few of the seed plants, typifies that of northern North American 
bogs. This biota analyses into seven horizontal ecological 
associations which ma}^ be designated as: (1) the Aquatic Asso- 
ciation, (2) the Sedge Association, (3) the Cassandra Association, 
(4) the Tamarack-Spruce Association, (5) the Cedar-Balsam- 
Hemlock Association, (6) the Roadside Association, and (7) the 
Hillside Association. 
Ecological succession takes place from the outer rim of the bog 
proper towards the inner lake area, the Sedge Association invad- 
ing the Aquatic Association, the Cassandra Association invading 
the Sedge Association, and these in turn followed successively 
by the Tamarack-Spruce and the Cedar-Balsam-Hemlock Asso- 
ciations. The Hillside Association belongs to the Forest on Sand 
Formation rather than to the Bog Formation. • The whole area 
might ultimately, if it had been left undisturbed by man, be 
succeeded by an association of a deciduous forest type. The 
Roadside Association has been brought about by the clearing of a 
narrow strip through the Cedar-Balsam-Hemlock Association and 
contains several species of plants and animals representative of 
the deciduous forest border type. 
The ingression of the biota into the region has been from sev- 
eral centers of dispersal. The biota of the Aquatic-Sedge Asso- 
ciations ingressed from the south; that of the Cassandra-Taniarack- 
Spruce Associations shows northern affinities. Evidence at present 
does not indicate that the biota of the Cassandra-Tamarack- 
Spruce Associations has ever existed, in any considerable part, 
south of the Wisconsin drift. The biota of the Cedar-Balsam- 
Hemlock and Hillside Associations is characterized chiefly by 
plants and animals having eastern affinities. The last ingression 
