256 



On the Work of the Coast Survey and the Fish 

 Commission of the United States. 



By Romyn Hitchcock, F.R.M.S. 

 (Address delivered June 22nd, 1883.) 



At the Fisheries Exhibition now being held at South Kensing- 

 ton, although the greater portion of the exhibits are outside our 

 province, still there are a great many things which are of a strictly 

 microscopical character. In the United States Department, for 

 instance, there is a fine collection of sponges sent by Mr. Peters, of 

 Philadelphia. Not only is there a large number of dried specimens, 

 but also mounted microscopical slides. 



Again, in the Swedish department there is a series of soundings 

 from the bottoms of some of the Swedish lakes, and these, under 

 the microscope, are of great interest, as there are great numbers of 

 portions of entomostraca amongst them, and they throw consider- 

 able light on the subject of the food of fishes. 



There are, however, few organic forms obtained in this manner at 

 great depths, and more may be done to collect them in the living 

 state by the use of the tow-net on the surface, and the dredge near 

 the bottom. I also think that by conducting these operations by 

 night as well as by day, much additional light would be thrown 

 on the fauna of the fresh-water lakes. 



In the aquarium of the exhibition, some of the fishes were 

 found in a diseased condition, and were seen to be covered with 

 flocculent spots. The fish became restless, and tried, by rubbing 

 themselves against the rock- work, to remove what troubled them. 



A microscopical examination of these spots showed that they 

 were caused by a species of fungoid growth, which has since been 

 cultivated, and found to be identical with that associated with the 

 salmon disease. 



With regard to the exploration of the deep sea bottom, this was 

 virtually begun by Dr. W. B. Carpenter in 1868, and to him science 

 is mainly indebted for much of the knowledge which it possesses 

 on the subject, and it was owing in a great part to his efforts that 

 the " Challenger " expedition was organized. 



