u 



Another peculiar feature of the past spring and summer was their high 

 temperature, and, in consequence, the early development and maturity of 

 the vegetation. Every month from March to August was warmer than the 

 average of thirty-seven years, as the following indicates : 



Warmer than Arerage. 

 Average. 1871. l»n. 



March 44-o° 49-5° 5-5° 



April 56.1 60.4 4.3 



May 66.2 67.2 i.o 



Spring 55.4° 59-o° 3-6° 



June 74.7° 78.8° 4-1° 



July 79.1 79.2 0.1 



August 76.7 78.5 1.8 



Summer 76.8° 78.8° 2.0* 



In the last thirty-seven years we have had three years in which the 

 spring was warmer, and four in which the summer temperature was higher 

 than in this year. In one of them — 1860 — the spring, as well as summer, 

 was warmer than this year. 



The years of warmer springs were 1842, 1844, i860; warmer summers, 

 1838, 1854, 1858 and i860. 



It must be remarked that the heat of the past summer was, nevertheless, 

 not excessive, the high average being produced rather by an absence of 

 great changes and occasional low temperatures. 



September made an exception to the rule which had prevailed through 

 the spring and summer. The changes were considerable, and the mean 

 temperature of the month, 66.8°, was considerably lower than the average 

 of this month, 69.2°. 



Mr. J. R. Gage was elected an associate member. 



October 16, 187 1. 



Dr. George Engelmann in the chair. 



Eleven members present. 



Publications received w^ere laid upon the table. 



Mr. C. V. Riley gave an abstract of a paper prepared for his 

 report, entitled "On the Cause of Deterioration in some of our 

 Native Grapevines, and the Reason why European Vines have 

 so generally failed in the Eastern half of the United States." He 

 showed that one of the principal causes of this deterioration and 

 failure was attributable to the workings of Phylloxera vastatrix 

 Planchon, a plant-louse, which formed galls on the leaves and 



