THE AMERICAN NATURALIST [Vol. XLII 



synopsis of the third has appeared in a recent issue of 

 Science 10 and need not be repeated. 



James W. Underwood, student and assistant in Olivet 

 College, (1) assisted in the work of the biological survey, 

 being occupied for some months in plotting out the dis- 

 tributions of the more frequent local species upon maps 

 which had been printed for the purpose ; (2) collected and 

 studied the species comprising the local plankton during 

 the spring season; (3) cooperated with the director in 

 the above mentioned study of the color variations of 

 Litorina palliata. 



Ralph E. Wager, A.M., teacher of biology, state 

 normal school, Potsdam, N. Y.— Studies of the degenera- 

 tive Changes in Hydroid Polyps under the Influence of 

 Changed Polarity or Contact Stimuli. Experiments 

 were performed for the purpose of providing material in 

 different stages of degeneration, with the object of sub- 

 sequently studying not only the histology, but more par- 

 ticularly the cytology of the changes. Abundant ma- 

 terial was at hand in the various species of Obelia, and a 

 sufficient supply of the degenerating polyps was obtained 

 to thoroughly test the killing and fixing methods, if not 

 to satisfy the demands of the problem. Thereafter ex- 

 periments were performed on Gonionemus for the purpose 

 of obtaining regenerating tissues, with a similar intention 

 of determining the cytological changes involved in their 

 growth. Again a plentiful supply of material was avail- 

 able, and enough of the regenerating tissues was obtained 

 to make possible a fairly thorough study. 



