562 



two or three feet, only yielded a small species of Bosmina and 

 5'oung forms of other Entomostraca, together with some rotifers ; 

 whereas at deeper levels numerous individuals of such com- 

 paratively large forms as Leptodora, Bythotrej)hes, Daphnia, 

 Biaptomus, Ci/clops, etc., were obtained. Going out in the boat 

 again about 10 p.m., they found that they could then get quite 

 near the surface, just the same sort of collection as they had 

 obtained earlier in the day from much greater depths. 



Mr. Earland said this phenomenon was very common in 

 respect to marine life. It was found that the tow-net brought 

 up very little in the day, whereas at night it was crammed. 

 He thought, however, the cause was more a question of heat 

 than of light. 



Mr. Scourlield regarded this as a very promising field for 

 research, and hoped some who were interested in the subject 

 would take it up. 



Mr. Bryce said he had often noticed that in a glass vessel 

 rotifers always gathered towards the side which was nearest to 

 the light. 



Mr. Wesche said he had found the same thing, and that 

 sunny days w^ere the best for catching rotifers. 



Mr. Still presumed that the effect of the light upon these 

 creatures was produced through the medium of their eyes, and 

 it might be inferred that the diffeience produced in the case 

 of rotifers and Daphnia might be due to the difference in 

 their eyes. 



The Chairman said their thanks were due both to the writer of 

 the paper and to Mr. Scourfield for reading it and telling them 

 •of his experiences upon Windermere. He suggested that next time 

 he should continue his researches beyond midnight, as he might 

 then ascertain at what hour the old ones went to bed. 



Mr. Karop read a paper on " Pocket Magnifiers," in the course 

 of which he described, and illustrated by diagrams, the various 

 forms which had been devised for the purpose. 



Mr. E. M. Nelson said Mr. Karop had incidentally mentioned 

 that the Lieberkiihn original microscopes had been lost, but he 

 was glad to be able to say that they were still existent. It 

 was Ijeeuwenhoek's which were lost. Lieberkiihn's were left to 

 the Royal College of Surgeons, and were still intact, and he 

 recently had the pleasure of seeing them there. 



