Ixii 



Election of officers then followed, resulting as follows: 



President — George Engelmann. 



First Vice President — C. Shaler Smith. 



Second Vice President — M. L. Gray. 



Corresponding Secretary — Nathaniel Holmes. 



Recording Secretary — Francis E. Nipher. 



Treasurer — Enno Sander. 



Librarian — Frederick M. Crunden. 



Curators — G. Hambach, Edw. Evers, W. B. Potter. 



Mr. Fred'k Ruschhaupt was elected to associate membership. 



January 17, 1881. 



Dr. Engelmann in the chair. Eleven members present. 



Mr. Nipher exhibited a raised map of Missouri, showing the 

 general features of topography. Upon this surface the lines of 

 equal variation of the magnetic needle had been drawn to repre- 

 sent the observations at 45 stations in the State. The results 

 seemed to indicate a marked relation between contour and the 

 position of the needle. 



Some discussion then arose on the relation between the age 

 and diameter of trees. It was stated by Dr. Engelmann, that 

 conifers in California, 6 ft. in diameter, were from five to six 

 hundred years old. The inner rings of growth ai^e generally 

 thicker than the outer ones. It sometimes happens that young 

 trees are shaded by older ones, and grow more rapidly after the 

 overshadowing trees have fallen. 



February 7, 1881. 



Dr. Engelmann in the chair. Eight members present. 



The Corresponding Secretary presented a paper by C. V. 

 Riley, entitled "Notes on North American Microgasters, with 

 Descriptions of New Species," which was referred to the Cmmit- 

 tee on Publication. 



He also reported a donation of papers on mining by Mr. Ed- 

 win Harrison, for which the thanks of the Academy were voted. 



