REPORT OF COMMISSIONER OF FISH AND FISHERIES. CTI1 
Considering the large number of species of aquatic animals, estimated 
at about a thousand in this country, which are used for food or for 
other economic purposes, and the amount of time required to make a 
careful analysis of a single species, some idea may be formed of the 
magnitude of any inquiry that would include the entire list. Whether 
or not it will eventually be considered advisable to analyze all or even 
the larger proportion of these edible forms is a matter not requiring 
immediate decision, but in his experiments thus far Prof. Atwater has 
selected a wide variety of species, including the more important ones, 
sufficient to furnish most instructive and interesting results. Prelim- 
inary reports upon the investigation were published in the Fish Com- 
mission Peports for 1880 and 1883, and contributions on the same sub- 
ject by Prof. Atwater have also appeared in the Peport of the Shellfish 
Commission of New York for 1887, the National Medical Dictionary, and 
the Century Magazine during 1887 and 1888. 
In view of the progress that has been made and the opportunity 
afforded for deductions, it has been deemed expedient to present 
in this volume a fall account of the researches now completed, and 
Prof. Atwater’s paper (Appendix 10, pp. 679-868) is deserving of care- 
ful consideration. The author explains that in its present status the 
investigation includes: (l) Chemical analyses of the flesh of American 
food- fishes and invertebrates; (2) experiments upon the digestibility 
of the flesh of fish; and (3) studies of the chemical constitution of the 
albuminoids of the flesh of fish. The experiments in regard to the last- 
named subject are not, however, sufficiently advanced to warrant their 
discussion at the present time. The report is divided into two parts, the 
first treating of chemical compositions, the second of nutritive values. 
Part I is chiefly occupied with the technical details of analyses, while 
Part II is more popular in character and explains the deductions at which 
the author has arrived, together with their bearing upon different fishery 
problems. 
The total number of species of fishes analyzed was 55 ; of mollusks, 
crustaceans, etc., 11; but the number of specimens, and consequently 
of separate analyses, was very much greater. The invertebrates made 
use of consisted principally of oysters from different localities, together 
with scallops, clams, mussels, lobsters, crayfishes, crabs, and shrimps. 
Many other kinds of food materials have also been subjected by Prof. 
Atwater to the same tests for the benefit of the National Museum, and 
the results obtained thereby are here utilized for comparison. 
The comprehensive manner in which the subject has been presented 
may be inferred from the following references to the principal contents 
of the report. In Part I are‘given the classification and origin of the 
specimens examined; methods of analysis; descriptions and details of 
the analyses; the results of the analyses presented in tabular state- 
ments; protein in the flesh of fishes; classification of the specimens in 
accordance with their chemical composition; summary of the analyses 
