REPORT OF COMMISSIONER OF FISH AND FISHERIES. XV 



125 fathoms. The results of this investigation will also be found in 

 Professor Verrill's report. 



The attention of Professor Verrill and his party, especially of Prof. 

 TV. N. Rice, was directed to investigations as to the best method of 

 preserving the invertebrates for museum purposes, and to improved 

 methods for killing in an expanded state such species as usually con- 

 tract when placed in alcohol. In regard to the preservation of Actinia 

 very satisfactory results were obtained by slowly adding a saturated 

 solution of picric acid to a small quantity of sea-water in which they 

 had been allowed to expand. When fairly dead they were transferred 

 to a pure saturated solution of the acid and allowed to remain from one 

 to three hours, according to size. They were then placed in alcohol of 

 about GO to 70 per cent, for permanent preservation. The alcohol should 

 be renewed after a day or two, and this repeated until the water is all 

 absorbed from the specimen. 



It was found that hydroids and most kinds of jelly-fishes can be easily 

 and beautifully preserved in the same way, but of these the specimens 

 may usually be placed alive directly in the acid of full strength. The 

 success with osmic acid was not so marked, the specimens contracting 

 more, and finally becoming so darkly stained as to render them useless. 

 Various trials were made with different kinds of drugs for the purpose 

 of killing marine animals in an expanded state, but no better method 

 was discovered than that of allowing them to suffocate in stale sea-water 



B— THE PROPAGATION OF FOOD-FISHES. 

 3. — EXTENT OF THE WORK. 



The work of propagation and distribution of food-fishes has been en- 

 larged year by year. Applications have been received from all of the 

 States and from four Territories. This has necessitated a continual ex- 

 pansion of the plans for each season's work. 



The work of the United States Fish Commission in multiplying use- 

 ful food-fishes was commenced in 1872, and has been prosecuted with 

 satisfactory results up to the present time. 



The species to which special attention has been directed are the shad 

 (Alosa sapidissima,) fresh-water herring or alewive, (Pomolobus pseudo- 

 harengus,) striped bass or rock-fish (Boccus lineatus,) California salmon 

 (Salmo quinnat,) the salmon of Maine (Salmo salar,) land-locked salmon 

 (Salmo sebago,) white-fish (Coregonus albus,) and the carp (Cyprinus carpio 

 and var.,) each of these having special relations to certain portions of 

 the country, and promising in their anticipated aggregate an extremely 

 .important addition to the food-resources of the United States. 



The States which have so far been the direct recipients of spawn and 

 young fish of more or less of these species are Maine, New Hampshire, 

 Vermont, Massachusetts, Rhode Island, Connecticut, New York, New 

 Jersey. Pennsylvania, Delaware, Maryland, the District of Columbia, 



