[7] FIRST DECADE OF UNITED STATES FISH COMMISSION. 59 
of a change from sea water into fresh water and from fresh water into 
sea water upon the young of different fishes. 
Mr. H. J. Rice carried on a series of studies upon the effect of cold 
in retarding the development of incubating fish eggs. 
A series of analyses have been made by Professor W. O. Atwater to 
determine the chemical composition and nutritive value of fish as com- 
pared with other articles of food. This investigation is still in progress. 
In connection with the work of fish culture much attention has been 
paid toembryology. The breeding times and habits of nearly all of our 
fishes have been studied, and their relations to water temperatures. 
The embrvological history of a number of species, such as the cod, shad, 
alewife, salmon, smelt, Spanish mackerel, striped bass, white perch, and 
the oyster, have been obtained under the auspices of the Commission 
by Messrs. Brooks, Ryder, Scheffer, Rice, and others. 
The introduction of new species, in water in which they were pre- 
viously unknown, is of special interest to the student of geographical 
distribution. Through the agency of the Commission, the German carp 
has already been placed in nearly every State and Territory, although 
the work of distribution has only just begun, and the tench (Tinca vul- 
garis) and the golden orfe (Idus melanotus) have been acclimated; the 
shad has been successfully planted in the Mississippi Valley and on the 
coast of California, and the California salmon in the rivers of the At- 
Iantic slope. The marena, or lake whitefish, of Europe, has been in- 
troduced into a lake of Wisconsin. It is not my purpose to speak of the 
great success in restocking with shad and salmon several rivers in 
which the supply was almost exhausted, and in planting the Schoo- 
dic salmon in numerous lakes. By an act of international courtesy, 
California salmon have been successfully introduced into New Zealand 
and Germany. The propagation work has increased in importance from 
year to year, as may be seen by the constant increase in the amount of 
the annual appropriation. A review of the results of the labors of the 
Commission, in increasing the food supply of the country, may be found 
in the annual reports; the rude appliances of fish culture in use ten 
years ago have given way to scientifically devised apparatus, by which 
millions of eggs are hatched where thousands were, and the demonstra- 
tion of the possibility of stocking rivers and lakes to any desired extent 
has been greatly strengthened. This work was for six years most effi- 
ciently directed by the late Mr. James W. Milner, and is now in charge 
of Maj. T. B. Ferguson, also commissioner for the State of Maryland, 
by whom has been devised the machinery for propagation on a gigan- 
tic scale, by the aid of steam, which is now so successfully in use, revo- 
lutionizing the art of fish culture. 
The investigation of the statistics and history of the fisheries has per- 
haps assumed greater proportions than was at first contemplated. One 
of the immediate causes of the establishment of the Commission was 
the dissension between the line and net fishermen of Southern New Eng- 
