y 



EEPORT OF THE SECRETARY. 47 



The improvement which has been made in the art of producing fish is 

 truly wonderful. Rivers, ponds, and lakes which are almost entirely 

 barren or inhabited only by fish of but little value may be filled to reple- 

 tion and kept full by judicious arrangement of the time of catching. 

 The rules, however, for the art of fish culture are founded on scientific 

 observations relative to the natural history of fish, and especially in 

 regard to one principle, namely : that nature, to preserve a species, is 

 prodigal in the production of individuals. This is especially true in 

 regard to fishes; for example, from a single shad may be stripped 10,000 

 eggs which, being left exposed to all the enemies to which they are sub- 

 jected, will yield not more than 50 young individuals able to feed them- 

 selves, and not more than 5 adult fish capable of reproduction, while 

 the same number of eggs hatched by artificial means ought to yield 

 9,500 youug fish, with a reasonable expectation of 950 adults. 



The subject of fish culture has, however, but lately attracted the 

 attention of the general government, the first small appropriation in 

 regard to it having been made in 1872. It has, however, been extended 

 year by year by small additional appropriations, and has now attracted 

 such attention that the country will demand a still wider extension of 

 its labors. 



In this connection I would draw attention to the immense importance 

 of the National Museum as an educational establishment. Specimens of 

 every variety of fish in the different waters of the United States are sent 

 by the employes of the Fish Commission to Washington in a fresh con- 

 dition, and from them molds are immediately made iu plaster from 

 which again models are cast and painted to give exact representations 

 in form and color of the original specimens. In this way in the course 

 of a limited time a full set of all the edible fish of North America will 

 be obtained, as well as models of those of a similar character from other 

 countries. In addition to this, the National Museum has now in its 

 possession ready for exhibition when a new building shall be provided, 

 specimens of all the apparatus used iii all the different countries of the 

 world for the capture and utilization, as well as the propagation of fish. 



The importance of such a collection as a means of diffusing and im- 

 proving practical ideas can scarcely be too highly estimated. 



CONCLUSION. 



It will be seen from the report of Professor JBaird that a large amount 

 of his time has been expended in labor for the general government, in 

 relation to American fisheries. 



Almost from the first organization of the Institution until the present 

 time the officers of the Institution have rendered service to the general 

 government without additional salary. For several years past the Sec- 

 ratary has devoted the greater part of the summer to investigations on 

 sound in its application to fog-signals, in connection with the Light- 

 House Board. 



