28 Bulletin Wisconsin Natural History Society [Vol. 12, Nos. 1 & 2 
The ecological status of the Aquatic Association of Ridgeway 
Lake at this time was probably not greatly different from that 
found in certain lakes in old sand dune regions today, which on 
account of more favorable conditions, often indeterminable, have 
not been invaded by the later successions of plant growth; among 
such lakes are Saint Germain and Fence in Vilas County, and 
Bardon in Idouglas County, Wisconsin. Lake Saint Cermain,^^ 
which will serve as an exami:)le for description of this stage, has 
by a combination of factors remained comparatively free from the 
invasion of vegetation; it is about three miles long l)y one and 
one-half miles wide; its shore line is simple and unbroken, and the 
surrounding hills are low; its long axis lies in a southwesterly 
northeasterly direction and its waters are subjected to much wind 
agitation, the prevailing winds during the summer ranging from 
south to west; it is relatively free from islands, the only one being 
a low esker in the western end of the lake; the drainage of the two 
inflowing streams is sluggish and, some three miles above Lake 
Saint Cermain, is in each case intercepted by lakes which act as 
settling reservoirs; the outflowing drainage on the other hand is 
(piite rapid. I have not determined the exact depth of the lake 
but it is known to be over forty-eight feet. All these factors, and 
])i*obably others not recognized, have tended to delay the extensive 
invasion of vegetation. I have somewhat crudely indicated (fig. 
7) the distriliution of the vegetation of this lake corresponding 
to that of the Aquatic Association in Ridgeway Bog. The char- 
acter of this vegetation differs somewhat in different parts of Lake 
Saint Germain; along the south shore and in the two large bays 
(fig. 8) at the southwest end of the lake the plants are mainly sub- 
merged aciuatics such as Potamogeton, Ceratophylluin, Char a, and 
a few Scirpus lacustris; along the north and northwest shores there 
is an inner, lakeward zone of submerged aquatics, which is fol- 
lowed immediately shoreward in some places by large beds of 
Nymphaea odorata, and these in turn by Scirpus lacustris which is 
present in greater or less abundance along this entire shore; in 
the small, sheltered bays and near the mouths of the inflowing 
creeks are found Nuphar advena, Typha latifolia, and, more inland. 
Iris versicolor. Associated with this flora are such vertebrates as 
liana pipiens, liana septentrionalis, Chrysemys hellii, Gavia inimer 
(in the oj^en water), Querquedula discors, Aix sponsa (wood duck). 
Observations at Lake Saint Germain were made August 18-23, 1910. 
