I4EP0RT OF COMMISSIONER OF FISH AND FISHERIES. XLIIT 



suiting in so great destruction. Vnrious causes have been assigned in 

 explanation of this mortality, some finding it in the parasitic leeches 

 that are swallowed by the fish and which attach themselves to the in- 

 testines with fatal results, others to lack of oxygen in the water as a 

 consequence of the intense heating of the shallow waters. 



Desirous of settling this matter in the best possible manner, I re- 

 quested Prof. S. A. Forbes, of Champaign, 111., one of the most eminent 

 biologists in the West, to proceed to Wisconsin and give personal at- 

 tention to this subject. He unfortunately arrived after the close of the 

 mortality, and was unable to ascertain anything definite on the subject. 

 He, however, made preparations of the viscera of a number of the dead 

 fish, and to his great surprise found that all thus affected gave evi- 

 dence of the presence in the liver, spleen, and other organs, of in- 

 numerable micrococci. He has not yet determined whether this was 

 the cause of the disease or its accompaniment, but proposes to con- 

 tinue the investigation. 



B.— INQUIRY INTO THE HISTORY AND STATISTICS OF 



FOOD-FISHES. 



IS. — THE WORK OF THE FISHERY CENSUS OF 1880 AND ITS RESULTS. 



In my report for 1882, pp. xliii-li, is given a brief account of the 

 results of the joint investigation of the fisheries of the United States, 

 undertaken in co-operation with the Superintendent of the Tenth Cen- 

 sus. It was stated that a division of the material had been agreed 

 upon, and that the manuscript of the report prepared for the census 

 was already in his hands. Two years have passed since that time, and 

 nothing has been accomplished by the Census Office toward the print- 

 ing of this report, which being in the main statistical, is fast losing- 

 part of its value. Colonel Seaton, the present Superintendent of the 

 Census, having requested that this manuscript, which he is unable to 

 print, be so far as possible published in the rej^ort of the Fish Com- 

 mission,, he has returned a portion of the same, which will soon be put 

 in the printer's hands, so as to form a section of the special quarto re- 

 port ordered by Congress. 



Prof/ress in printing the quarto Fisheries Report. — The special quarto 

 report upon " The Food-Fishes and Fisheries of the United States," 

 ordered printed in 1882, is slowly being put in type, about 1,200 pages 

 being already completed and a large number of illustrations engraved. 

 The first section, devoted to the natural history of useful aquatic ani- 

 mals of the United States, with an atlas of 277 i^lates, has been en- 

 tirely finished for some months, and its publication is awaiting the con- 

 venience of the Public Printer. The other parts of the report are 

 ready, and it is hoped that in 1885 a great deal of progress will be made. 

 The contents of the entire report will be, approximately, as follows : 



