REPORT OP COMMISSIONER OF FISH AND FISHERIES. 169 



favorable couditious. A few papers bearing upon the former group 

 have appeared in the publications of the Fish Commission and U. S. 

 National Museum from time to time. In 1884 Prof. Edwin Linton, 

 of Washington and Jefferson College, began an exhaustive inquiry 

 respecting the entozoan worm parasites of fishes, Avhicli has been con- 

 tinued down to date. Three general papers on this subject have been 

 printed in the annual reports of the Commission for 188C, 1887, and 

 1888, and a sjiecial account of a parasite of the tiger shark in tlie last- 

 mentioned report. The protozoan parasites occurring on Cyprinodon 

 in the Vineyard Sound region, and on cyprinoid fishes in Ohio, have 

 also been discussed by Prof. Linton in the Fish Commission Bulletin 

 for 1889. The entozoan parasites of the trout collected by Dr. Jordan 

 in the Yellowstone Park, in 1890, were referred to Prof. Linton for in- 

 vestigation, and the following year he accompanied Prof. S. A. Forbes 

 on an expedition fo the same region, where he was able to study the 

 same forms in a ti-esh condition and to trace their development through 

 the pelican. An account of his researchesln respect to this subject 

 will be found under the heading of the Yellowstone National Park. 



The attention of the Commission has been called to several instances 

 where young trout kept in confinement have become blind. Specimens 

 in this condition were carefully examined by Prof. Linton, but no trace 

 of parasitism was discovered. The eyes were congested and there ap-< 

 peared to be an. unusual amount of pigment in the choroid coat and in 

 the vicinity of the crystalline lens. It seems probable, therefore, that 

 the trouble arose from some external conditions surrounding the fish, 

 and which affected only the eyes, as the specimens were otherwise in 

 good condition. 



COLLECTIONS, PREPARATION OF REPORTS, ETC. 



The laboratory established at the Central Station in Washington at 

 the close of the fiscal year 1889 has, up to the present time, met the 

 principal requirements of the work of this division, but it is rapidly 

 becoming overcrowded and furnishes insufficient accommodations for 

 taking proper care of specimens obtained in the investigations now in 

 progress. Very large collections have been received during the past 

 two years, resulting mainly from the explorations of the steamer Alba- 

 tross in the North Pacific Ocean and in Bering Sea, from the oyster 

 surveys along the Atlantic coast, and from the inquiries respecting 

 the lakes and rivers. While it is not proposed to retain permanently 

 in the Fish Commission building more than a type or working series 

 of the specimens thus obtained, yet a considerable time nuist elapse 

 before any extensive collection can be fully studied and the reports 

 bearing upon it prepared for printing, and ample storage and working 

 space is therefore required for the accommodation of this branch ol 

 research. 



The study of the fishes has progressed rapidly under the care of Dr. 

 Tarleton H. Beau, the ichthyologist of the Commission, and through 



