2 MICHIGAN BIRD LIFE. 
of the great lakes by which the state is nearly surrounded. It has long been 
known that considerable bodies of water exert a local influence in modifying 
climate and especially in averting frosts, but it has never been suspected that 
Lake Michigan, for instance, impresses upon the climatic character of a broad 
region an influence truly comparable with that exerted by the great ocean. 
Some years later in an important article on the plant life of the state,* 
we find the following statement probably written by Erwin F. Smith: 
“The climate of the Lower Peninsula is not as severe as that of the Upper, 
nor so even, but is subject to frequent, sudden, and extreme changes of 
temperature—as great a variation during the winter season as 53° Fabr. 
in less than 24 hours having been recorded. Such rapid changes more or 
less affect vegetation, especially the tender branches of cultivated trees, 
which are sometimes seriously injured. In one or two instances a like effect 
on our forest trees has been noticed. The annual range of temperature is 
about 116°, and the annual mean 46°. Of rainfall, including what falls 
in form of snow, we have, yearly, about thirty inches. Our snowfall is much 
less, for the same latitude, than that of New York and England. In the 
center of the peninsula, we seldom have more than a few inches at a time.” 
DISTRIBUTION OF PLANT LIFE. 
The general distribution of plant life in the state thirty or forty years ago 
can hardly be better described than in the words of the authors already 
quoted, C. F. Wheeler and Erwin F. Smith.* It should be remembered 
that at that date the lumbering interests of Michigan had recently passed 
their maximum of development, but there were still immense areas of noble 
pine forests left. 
“The proximity of the Great Lakes exerts a marked influence in equalizing 
the temperature, and the effects are marked upon our flora. 
“Trees like Liriodendron Tulipifera (tulip tree), Asimina triloba (paw- 
paw), Cercis Canadensis (red-bud), Gleditschia triacanthos (honey locust), 
Cornus florida (flowering dogwood), Nyssa multiflora (sour gum), and Morus 
rubra (mulberry), which belong to Ohio and Central Illinois, have crept 
northward, favored by the mild influence of the lake winds, through the 
central and western part of the Lower Peninsula, often beyond the middle, 
and the same is true of smaller and less noticeable plants. 
“As might be expected from the uniform surface of the peninsula, the 
flora is much alike throughout. Probably three-fourths of our species are 
common to all sections, though by no means equally distributed; some being 
very abundant in one district and rare in another at no great distance. In 
most cases such change is due to soil rather than to difference in elevation, 
temperature, or atmospheric moisture. 
“The Lower Peninsula is covered with a deep drift of alternating sands, 
clays, and gravels, and the flora of any section depends chiefly on which 
of these happens to lie uppermost. With reference to its flora, the peninsula 
may roughly be divided into two great divisions—the hardwood and the 
softwood lands; one representing the Appalachian flora, and the other the 
Canadian. 
“The hardwood country lies south of latitude 43°, and consists of very 
fertile sand, clay, or loam, mostly cleared of the original forest, and largely 
cultivated. 
* Wheeler and Smith, Michigan Flora, An. Rep. (Mich.) State Hort. Soc., 1880, pp. 428 et. seq. 
