124 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
gations were placed under the direction of Dr. David Starr Jordan, 
president of Leland Stanford Junior University, and Dr. Barton W. 
Evermann, ichthyologist of the Commission, with the following assist- 
ants: Mr. John N. Cobb and Mr. E. L. Goldsborough, of the Fish Com- 
mission, as statistician and general assistant, respectively; Dr. Oliver 
P. Jenkins, of Stanford University, as volunteer scientific assistant; 
Mr. A. H. Baldwin and Mr. C. B. Hudson as artists. 
The party sailed from San Francisco May 30 and landed at Hono- 
lulu June 5. With Honolulu as. headquarters, the investigation was 
begun of the commercial fishes and fisheries of the island of Oahu 
and was well under way at the close of the fiscal year. 
DISEASES OF FISHES. 
During the year the study of the diseases of wild and domesticated 
fish has received inereased attention. Mr. M. C. Marsh, the assist- 
ant who has been assigned to this branch, has devoted most of his 
time thereto, and for the purpose of better fitting himself for the 
consideration of this intricate subject, has taken special laboratory 
instruction in human pathology and in bacteriological methods... 
Owing to the newness of the subject there is very little reliable 
published information on the etiology, pathology, and treatment of 
fish diseases, and a great deal of pioneer and preliminary work must 
be done in order to be in position to interpret the phenomena of 
disease and devise measures for its amelioration. It has already been 
determined that bacteria are the most potent factors in the causation 
of fish diseases, and the thorough study of these organisms and the 
perfection of cultural methods applicable to the special class of 
animals under consideration are of fundamental importance. As the 
study of fish pathology has progressed it has become more and more 
evident that accurate deseriptions of the normal functions and strue- 
ture of the various species of food-fishes are necessary, and the 
absence of comprehensive information of this character is strongly 
felt. There is searcely one of our food-fishes which has been the 
subject of a systematic physiological and anatomical examination, and 
until this is done the interpretation of diseased conditions and the 
institution of remedies therefor can not be intelligently undertaken. 
The diseases demanding and receiving most attention during the 
year were epidemics affecting the brook trout at the Manchester, 
Iowa, and Northville, Mich., stations of the Commission. Several 
weeks in July, 1900, were spent at the former station in studying a 
trout disease, apparently the same as that which was found at North- 
ville in the previous year and which reappeared in the spring of 1901. 
The investigation of the Northville epidemic continued through June 
and was in progress at the close of the year. 
Prof. Gary N. Calkins has reeently described * a disease affecting 
the brook trout on Long Island, N. Y., and attributable to a newly 

* Report of Commissioners of Fisheries, Game, and Forests of the State of New York for 1900. 
