13S Bulletin Wisconsin Natural History Society [Vol. 13, No. 3 
woods very nearly to the lake at about the central portion of 
the formation. The most important and dominant plant is 
the dogwood Cornus stolonifera, together with occasional willows, 
Salix discoloi'. These willows are often infected with the 
gall of the common willow parasite Rhabdophaga strabiloides ; 
examination has shown that in the fall between 75% and 80% 
of these galls contain the eggs of the meadow grasshopper 
Xiphidium fasciatum in abundance. This society is very dense 
in so far as the flora is concerned, and it is a very difficult matter 
for a person to make his way through some of the tangles. 
Here, then, though primarily a swamp society, we find a 
biota radically different from that of the surrounding society. 
It is to be expected that the fauna of the surrounding society 
encroach at times upon this area, and such is found to be the 
case. Being encircled usually by the Spartina bird species, 
certain of the sparrows, the wrens, and the blackbirds are some- 
times here. In a like manner, due to the tangle and density 
of the vegetation, some of the wood-seeking species are found, 
as an occasional nuthatch, brown creeper, or downy 'wood- 
pecker; but this must be considered as outside of their ordinary 
zone. 
Characteristic, however, of this region at different times of 
the year are the woodcock, quail, partridge, and the shrike. 
3. The Fonticular, or Springs Association. Here we have as 
the dominant plant the cress Radicula nasturtium-aquaticum, 
and the dominant invertebrates as recorded previously. Cer- 
tain fish are also found here, as the mud-minnow, top-minnow, 
and stickle-back, and these are responsible for the presence 
around the springs of some of the larger birds found there, though 
we can not say that the springs are responsible for the presence 
in the region of a single species of bird, nor is there a single species 
characteristic of them. The spring basins abound with amphi- 
pods, and as these are a favorite food of the rails, it is not sur- 
prising that they are occasionally to be found in the immediate 
vicinity (6). This is a very small association, of relatively 
little importance. 
4. The Argian, or Field Association. In so far as the region 
under discussion is concerned, the fields there present may be 
considered as intermediate between the swamp and the woods 
