REPORT OF COMMISSIONER OF FISH AND FISHERIES. XLV 



has been so successful? in his preliminary efforts in this direction, that 

 the Austrian Government has authorized him to attempt the developnient 

 of this industry on the coast of Dalmatia. The process is very simple, 

 consisting in selecting the proper season in the spring, and dividing a 

 living, marketable sponge into numerous pieces, and fastening them to 

 stakes, which are driven mto the sea bottom so as to submerge them. 

 These fragments at once begin to grow out, and at the end of a certain 

 time each one becomes an entire sponge. 



According to Dr. Schmidt, three years is a sufficient length of time to 

 obtain from very small fragments sponges worth several cents apiece. 

 In one experiment the cost of raising 4,000 sponges amounted to about 

 $45, including the interest for three years on the capital employed. The 

 sales amounted to $80, leaving a profit of $35. 



It was my intention to give a detailed account of the practical results 

 of the work prosecuted by the Commission from the beginning, showing 

 the aggregate of work done and the promise of future success, by the 

 reappearance as adults of the young fish which had been planted in 

 their localities. Owing, however, to necessary delay in the preparation 

 and the publication of this report, it has been thought expedient to keep 

 this history for the report of 1879, when it is hoped that sufficient evi- 

 dence will be given to show that all reasonable anticipations of a suc- 

 cessfal outcome have been realized, and that the future holds in store 

 great possibilities of ever-increasing food resources, which, so far as the 

 United States is concerned, is to have a very important economical 

 bearing. 



It must be borne in mind, too, that the United States Fish Com- 

 mission is only one of many in operation in the same direction in 

 the country, very many states now having commissioners devoted to 

 their work, and all more or less successful either in the artificial propa- 

 gation of fishes in extending the distribution of species already oc- 

 curring in the waters, or in the introduction and enforcement of i^rotec- 

 tion of fishes during the critical periods, without which the most ex- 

 tensive efforts in fish culture will fail of their object. 



D.— HUMAN AGENCIES AS AFFECTING THE FISH SUPPLY, 

 AND THE EELATION OF FISH CULTURE TO THE AMER- 

 ICAN FISHERIES.* 



6. — INFLUENCE OF CIVILIZED MAN ON THE ABUNDANCE OF ANIMAL 



LIFE. 



It may safely be said that wherever the white man plants his foot and 

 the so-called civilization of a country is begun the inhabitants of the 

 air, the land, and the water, begin to disappear. The bird seeks a new 



* This article, exactly in its present form, was written for presentation elsewhere, 

 but not published. It was intended to constitute a poimlar exposition of the sub- 

 ject to the end of 1878, and consequently includes to a considerable extent data con- 

 tained in the previous pages. 



