23 



I wiould like to ask Mr. Cooper whether, under the cHmatic 

 conditions of Isle Royal, there is not good reason to believe 

 that these rings have practically an absolute year-value ?" 



Mr. Cooper. — "No attempt was made to study that subject, 

 but in a general way the method yields fairly accurate results." 



W. S. Bayley called attention to the fact that the more in- 

 telligent woodsmen on the neighboring mainland believe that 

 the rings indicate the ages of the northern trees, basing their 

 belief upon the fact that the positions of several double sets 

 of rings seen in almost all trees correspond accurately to the 

 dates of several seasons, when the trees budded twice. 



He also stated that the rocks on Isle Royal comprise a series 

 of sandstones, conglomerates and lavas of very different com- 

 positions. The Cambrian, on the south side of the island, is 

 almost a pure quartzite. The same types of rocks occur in that 

 portion of Minnesota north of Lake Superior, and so far as 

 known there is no difference in the character of the forest 

 corresponding to differences in the character of the rock. He 

 asked the speaker if the forest covering over the Cambrian 

 quartzite on Isle Royal was noticed to be different from that 

 over the Keweenawan beds. 



Mr. Cooper. — "The forests on the different formations seemed 

 to be of the same general type." 



T. L. Hankinson presented the following paper: 



AN ECOLOGICAL STUDY OF THE FISH OF A SMALL 



STREAM. 



In this paper I will attempt to set forth the nature of my 

 studies of the fish life of the streams about Charleston, 111., 

 by considering some of the methods employed and the results 

 obtained in investigating the fish of a particular stream, called 

 by a few of us "Campus creek" because a portion of its 

 water comes from the Normal School campus. Although more 

 or less attention has been given to this stream for about six 

 years, a systematic investigation of its fauna and flora has been 



