32 Pecwh-Gromng 



it. For this reason, vegetation within the zone of this in- 

 fluence advances more slowly in the spring than it does out- 

 side of it. The tendency, frequently very marked, is for 

 the blossoming of peach trees situated within the zone to be 

 delayed until after the season of spring frosts is past. 



In the fall, frosts are delayed in a similar manner, except 

 that the large body of water, having absorbed much heat 

 during the summer, cools off more slowly than the atmos- 

 phere, and hence tends to keep the temperature within 

 its zone of influence warmer than it would otherwise be. 

 In some cases the winter temperatures are also modified 

 by large bodies of water, even though they may be frozen 

 over for long periods. 



It is because of these reasons that peaches are grow^n with 

 marked success, and injury to the crops by adverse tem- 

 perature conditions is comparatively infrequent in the 

 parts of New York and Ontario that border Lake Ontario ; 

 in Ohio along Lake Erie; in southwestern INIichigan on 

 Lake ^Michigan ; and in some other districts w^hich are ad- 

 jacent to large bodies of water. As a rule, the zone of in- 

 fluence of bodies of water, such as those named, is rather 

 narrow, usually not extending back from the shore more 

 than a few miles. However, the topography, and especially 

 the degree of the slope of the land from the water, deter- 

 mines very largely the extent of the area affected thereby. 



A striking illustration of the ameliorating effect of water 

 is in the difference in the winter temperatures that prevail 

 on opposite shores of Lake Michigan. One of the most 

 regularly successful peach-growing regions in the United 

 States is a narrow belt along the lake shore in western Michi- 

 gan, the belt extending as far north as Grand Traverse Bay. 

 The winter temperature in this belt rarely drops much be- 



