REPORT OF THE COMMISSIONER OF FISHERIES. 113 



regretted that the region in question can not be entirely free from 

 suspicion of having sent out polluted oysters. The situation is fully 

 appreciated by the oyster dealers and the local authorities, and it is 

 believed no further danger need be feared. 



Disease at Cold Spring Harbor^ New York. — In May and June a 

 visit was made to the Cold Spring Harbor station of the New York 

 Forest, Fish and Game Commission, to examine into the cause of 

 a serious mortality among yearling and adult brook trout. This 

 was determined to be due to a parasite, Lymphosporldium truttse, 

 described by Professor Calkins. The disease destroyed nearl}'^ all 

 the older trout, and advanced, entirely unchecked by remedies. It is 

 believed to be amenable to control as respects future outbreaks by 

 cementing the ponds, by the practice of disinfection to kill all stages 

 of the parasite, and by avoiding too heavy a stock of yearling and 

 older trout. 



Menhaden mortality in Narragansett Bay. — In May and June an 

 extensive mortality among menhaden occurred in Narragansett Bay, 

 and the disease was also found at New Bedford. By the last of June 

 the mortality seemed to have ceased. Prof. F. P. Gorham, of 

 Brown University, investigated the disease by making cultures from 

 the dying or dead menhaden, and obtained a bacterial organism in all 

 cases. At the close of the fiscal year he was studying the relation of 

 the organisms to the disease. 



Besides the more detailed inquiries, Mr. Marsh made special inves- 

 tigations concerning diseased fish, contaminated water supply, and 

 other difficulties besetting fish-cultural operations at Northville, Mich. ; 

 Wytheville, Va. ; Erwin, Tenn. ; Allentown, Pa. ; and Nashua, N. H. 

 During the spring of 1904 an exhibit of bacterial organisms patho- 

 genic to fishes and of others related to the fisheries was prepared for 

 display at the Louisiana Purchase Exposition. 



WOODS HOLE LABORATORY (dR. F. B. SUMNER, DIRECTOR). 



The laboratory of the Bureau at Woods Hole, Mass., was thrown 

 open on the 16th of June, 1903, for the nineteenth summer since the 

 establishment of its present quarters, and scientific work was in prog- 

 ress until the end of September. The work accomplished during the 

 season is summarized below, together with especial mention of certain 

 important lines of work which were planned and commenced. 



Equipment. — In addition to the large laboratory room with 9 tables, 

 there were 14 private rooms at the disposal of investigators, all of 

 which are provided with gas and electricity, and otherwise equipped 

 for research. To this must be added the libsary, supply room, and 

 aquarium, as well as the main hatching room, which, as usual, was 

 available for laboratory purposes from the end of the lobster-hatching 



F. C. 1904 8 



