130 Bulletin Wisconsin Natural History Society [Vol. 13, No. 3 
direction. Here its course is choked with large beds of water- 
cress, which greatly retard the flow of water. 
Among this cress aquatic life of direct bearing upon the 
avifauna of the region abounds. Here again we have the min- 
now Notwpis heterodon , together with the stickle-back Eucalia 
inconstans and the mud minnow Umbra limi, the only fish found 
in the stream until it approaches the lake closely. Here also we 
have a third species of caddice-fly larva, Neuronia postica , 
not found in the three smaller streams. Insect life abounds 
here in the shape of the water scorpion Ranatra fusca, the com- 
mon water-bug Zaitha fluminea, the whirligig beetles Gyrinus 
a?ialis, various species of water beetles of the genus Dytiscus, 
as well as nymphs of may-flies, damsel-flies, and dragon-flies. 
Tadpoles are found among the cress, which is another respect 
in which the stream differs from the preceeding springs. Two 
species are represented both in tadpole stage and in the adult: 
the leopard frog Rana pipiens, and the green frog Rana clamitans, 
while the cricket frog Acris gryllus is found in the adult form 
only. These frogs attract the bitterns and herons found along 
the banks. The reptiles are represented in the water-cress 
region only by the painted turtle Chrysemys cinerea, while near 
the water an occasional water-snake Natrix sipedon is found. 
The Woods 
The woods may be divided in a general way into two zones : 
the oak zone, and the poplar thicket zone, each with its more 
or less typical biota. The oak zone is dominated by the red 
oak Quercus rubra with a goodly representation of the white 
species, Quercus alba. The elm Ulmus americana is represented 
less abundantly. The white oak is found most commonly along 
the edge of the woods, and a great number are infected with 
the oak gall Holcaspis inanis, while upon the red species is found 
the smaller gall Holcaspis globulus. The poplar thicket is dom- 
inated by the aspen Populus tremuloides and an occasional white 
poplar Populus alba. Each of these zones has its characteristic 
avifauna; this subject will be taken up under the heading of 
Zonation. 
