162 ANNUAL REPORT. , ; 
from the physical system, the proportions of which are in ratio 
to the degree of cold and the velocity of the wind, and as v 
life is in many respects partially if not wholly subject to conditions 
which affect the physical system, it is to be presumed that the ve- 
locity of the prevailing winter winds, passing as they do, over a 
large extent of treeless plains of the northwest, must be very great, 
and that the extraction of heat and exhalation of moisture from ex-— 
posed vegetation must be in proportion to the degreef cold, velocity 
of the wind and the length of time during which those adverse con- 
ditions prevail. The effect of these influences upon trees that have 
made so late a growth in autumn as to leave imperfect cellular for- 
mation in the whole or any portion of the trees, in combination with 
either a very wet or dry soil, may be partially manifested in injury 
to the imperfectly formed cells of the roots, or the bursting of the 
bark at or near the collar, or rupture of the inner bark and wood 
cells of portions of the stems and at the junction of branches with 
the bodies of the trees, or the injury may be confined to the extrem- 
ities of the branches, or in extreme cases when subjected to many 
or all of the conditions adverse to the sustenance of vegetable life, 
the trees may be injured in every part of their organization. As 
the longevity of fruit trees is dependent upon the peculiarities of 
their constitutional organisms, and upon the climatic conditions to 
which they are subjected, and as the latter conditions are extreme— 
and as these extreme conditions are violent extremes of cold and 
heat, and as these extremes are dependent upon the velocity and 
direction of the wind, and as the coldest and strongest winter winds 
are from the northwest, and as the thermometer ranges the lowest 
when the wind is in the northwest and highest when the wind is in 
a southerly direction, and as the degree of extraction of heat and 
the volume of exhalation of moisture is greatest when the winter 
winds are in the northwest, and as the results of these dependent 
forces are injurious in their effects upon vegetable growth, it is, 
therefore, to be presumed that the strong winter winds are the 
principal causes of injury; and that, if by any means orchards can 
be so protected so as to break or impair the force of the wind, the 
injuries manifested in orchards will be lessened in like proportion. 
If this be true, tender varieties planted and tested in orchards which 
are to be found located in the heavy timber lands, (some of which 
have the original forest growth so located as to break the force of . 
the wind upon one or more sides of the orchard,) would undoubt- 
edly afford instances tending to disprove, or substantiate the con- 
clusions herein deduced. The majority of, if not all the intelli- 
gent horticulturists of the State concede that many varieties of 
apple trees are more hardy and productive in the heavy timber 
counties bordering on the western shore of Lake Michigan, than the 
same varieties grown in the oak openings, or in the prairie sections, 
The productiveness of tender as well as hardy varieties in the lake 
shore timber counties, may be partially attributable to the influence 
which so large a body of water as Lake Michigan must necessarily 
exert upon the atmospheric currents in the summer season, but this 
influence is not as considerable as many might presume, from the 
fact that the prevailing summer wind is southwest, while in the 
