1920 



ENTOMOLOGICAL SOCIETY. 



47 



Jersey, West Virginia, Oklahoma, Virginia, North Carolina, and Tennessee. 

 (Fig. 3.) 



Fig. 3 is a calendar of winter wheat seeding date constants for map (Fig. 1) 

 computed for latitude, longitude and altitude. To illustrate its use let us select 

 the Guelph region. This lies in the quadrangle bounded by the phenological 

 meridians 45 and 50 and the isophanes 47 and 48 and at an altitude of 1,000. feet. 

 By referring to Fig. 3 it will be seen that the date for winter wheat seeding , is 

 September 10th for an altitude of 1,000 feet. Next, by referring to Fig. 3 we find 



Fig. 3. Calendar of wheat seeding date constants for Isophanal Map. Fig. 1. a 

 Isophanes. The dates in this calendar are the computed constants for the given altitudes 

 to be corrected for the 5x5 quadrangles of Fig. 2, by adding the + and subtracting the 

 —autumn date which will give the general average date for the average altitude and 

 average season. 



Che departure constants are for fall events. For this locality, therefore, the 

 best date for winter wheat seeding is September 10th. 



It is impossible in the short time allotted me for the presentation of this 

 paper to give in detail the many interesting studies made by Dr. Hopkins in the 

 formulation of his Bioclimatic Law. Such details will be found in Svpfrm"ni 

 No. 9 of the Monthly Wenther Beview, issued May 1st, 1918, and in an article in 

 the June, 1919, number of the Scientific Monthly. 



