680 REPORT OE COMMISSIONER OF FISH AND FISHERIES. 
taken .at the instance of the U. S. National Museum, to furnish data for 
illustrating and explaining its food collections. These analyses form an 
important economical supplement to the investigation herewith reported, 
because of the desirability of data for comparisons of fish with other 
foods. Some of the principal results are embodied in the tables of com- 
position of food materials in Part II. 
The studies of the digestibility of the flesh of fish were carried out 
in the physiological institute of the University of Munich. I am in- 
debted to Professor Yoit of that university, not only for the hospitali- 
ties of his laboratory but also for kind assistance. As the details of 
the experiments have been published elsewhere, only the main results 
are recapitulated here. 
An investigation upon the constitution of the flesh of fish was begun 
in the physiological institute of the University of Heidelberg, where 
opportunities were furnished through the courtesy of Professor Kiihne, 
to whom also I wish to express my indebtedness. The investigation 
has been continued in the laboratory of Wesleyan University, but has 
not reached that stage of completion which would make the publication 
of results satisfactory. Circumstances may hereafter permit its further 
prosecution, and the outcome may be combined with other studies, 
including those of dietaries of which fish forms or should form a part. 
All of the work of investigation here reported, except that upon the 
digestibility of fish, was performed at Middletown, Connecticut, in the 
chemical laboratory of Wesleyan University. 
While the work has been constantly under my immediate supervi- 
sion, and much of it has been done by myself, the larger part of the 
details have been skillfully and faithfully performed by my assistants, 
Messrs. G. P. Merrill, W. H. Jordan, J. H. Long, Miles Beamer, E. B. 
Voorhees, E. W. Rockwood, and especially C. D. Woods. The last- 
named gentleman has performed the larger portion of the work of 
analysis and calculation of results besides contributing very materially 
to the elaborating of the methods of analysis and assisting in numerous 
other ways, including the preparation of diagrams and reading of proofs. 
Thanks are due to Mr. F. T. Lane, of New Haven, Connecticut, Mr. 
J. E. Ely, of Baltimore, Maryland, to Messrs. Dorlon & Shaffer, of New 
York, and to Mr. E. G. Blackford, fish commissioner of the State of 
New York, for a large number of specimens of fish and invertebrates 
generously furnished for analysis, and for valuable information as well. 
Especial thanks are due to Mr. Blackford, not only for a very con- 
siderable number of specimens and for information which was extremely 
helpful, but also for a gift of $100, which was used in defraying some of 
the incidental expenses of the analysis of invertebrates. 
I wish also to acknowledge the generous contribution of Mr. A. R. 
Crittenden, of the firm of Wilcox, Crittenden & Co., of Middletown, 
Connecticut, of $100, which was used in defraying part of the incidental 
expenses of the analyses of fish. 
