JACKSON APPARENT EFFECT OF WINTER INACTIVITY 
61 
width at the summit. Little Manitou Island will soon meet the fate 
of Steamboat Island which has entirely disappeared by action of wind 
and waves within the memory of man. 
There is for the most part a general similarity in the topography of 
the islands. The east and northeast sides generally rise from the 
water’s edge in precipitous red sandstone cliffs varying from 10 to 80 
feet high, usually 10 to 30 feet. Sandy beaches are most likely to be 
on the southwestern shores. Northern, western, and southern slopes 
are frequently steep clay-banks. A few more or less intermittent small 
creeks offer some surface drainage, but most of the precipitation washes 
directly down the banks into the lake. There are a few sloughs sur- 
rounded by marshes and bogs on some of the islands, the largest being 
near Big Bay on the southeastern side of Madeline Island midway its 
length. Other sloughs of considerable size are near the southwestern 
corner of Outer Island, and near the base of Presque Isle Point towards 
the eastern end of Presque Isle. Each of these sloughs has been formed 
by a separation of a body of the lake by sand beaches. The inland 
sides of the sloughs tend to be more boggy than the outer sides. These 
bogs contain a vegetation typical of sphagnum-cassandra bogs, the 
tamarack and spruce growth being limited. They differ in no essential 
features from the same type of bog on the mainland. 
The islands are covered with a Canadian Zone vegetation which on 
Outer, Michigan, Cat, and a few other islands has been undisturbed by 
civilization but on others has been more or less destroyed by lumber- 
men. Spruces {Picea canadensis and mariana), balsam fir {Abies 
balsamea)j pines {Pinus strobus, resinosa and divaricata), arbor vitse 
{Thuja occidentalis), {Tsuga canadensis)^ ground hemlock 
{Taxus minor) , mountain maple {Acer spicaturn), mountain ash {Sorbus 
americana)j birches {Betula papyrifera, lenta and lutea), and aspens 
{Populus tremuloides) constitute a greater portion of the vegetation, 
while around the bogs and sloughs is found a growth of alders and 
willows. In all ecological features the islands offer an environment 
for mammals similar to that of the mainland and on casual observa- 
tion one would think conditions ideal for an abundance of mammalian 
fife. As a matter of fact mammals are poorly represented in number 
of individuals and, even more so, in number of species. 
