236 PEOCEEDIXGS OF UNITED STATES NATIONAL MUSEUM. ^ 



3. Iiiject alcoliol in the mouth and the vent, to preserve the viscera. 

 Make small incisions in the belly and in thick parts of the body, to allow 

 the alcohol to penetrate the tissues. It is nearly always desirable to 

 remove the liver, stomach, and intestines from hirge lish, and to pre- 

 serve these separately, numbering them so as to correspond with the 

 fish from which they are taken. 



4. It is a good plan to keep freshly collected fishes in weak alcohol 

 for a day or two; a mixture of two parts of 95 per cent, alcohol to one 

 of water will answer for this temporary immersion. Some species are 

 exceedingly soft and llabby, falling to the bottom of a glass jar or other 

 receptacle, becoming partly imbedded in their own mucus, and rapidly 

 disintegrating in consequence. Such specimens should either be sus- 

 pended in the alcohol by a thread or string from the neck of the jar or 

 the hook sometimes found on the inside of the stopple, or a bed of excel- 

 sior or muslin should raise them from the bottom 5 these are necessary 

 X)recautions which will prevent many losses. After the fish haA^e been 

 kept for not more than two days in the weak alcohol, transfer them to 

 a mixture of three parts of 95 per cent, alcohol to one of water. Ordi- 

 narily this latter will preserve specimens that are not crowded too much 

 at least three months; some, of course, will remain in good condition 

 still longer; but, generally, three months will reduce the preservative 

 power of the liquid so far as to make a renewal of alcohol necessary. 

 The tendency with many collectors is to overcrowd specimens, and, as 

 a result, museums frequently receive a lot of half-rotten material which 

 is too valuable to be thrown away and is yet always a source of trouble 

 and disnpjiointment. Ajar, tank, or case of any kind should never be 

 expected to accommodate more than half its own bulk of flsli, and even 

 this proportion will require watchfulness to avoid loss If a collection 

 freshly caught is to be shipped to a distant museum or private collec- 

 tion, observe the directions about cleansing the fish and preserving the 

 viscera separately if needful, and then use nothing weaker than a mix- 

 ture containing three parts of 95 per cent, alcohol and one part of water. 

 A good mixture which will carry fish in very nice condition is the 

 following: 95 percent, (or absolute) a'cohol, 3 quarts; water, 1 quart; 

 glycerine, 1 pint; borax, 1 ounce. There is nothing better, however, 

 than the mixture of three parts of alcohol and one of water. 



5. The extensive collections of the United States Fish Commission 

 are usually i^acked in copper tanks, which are tin-lined within. The 

 lid of the tank is made to screw in the top and its diameter is always 

 as great as the dimensions of the top will allow. The tanks (called 

 Agassiz tanks) are made to contain 4, 8, or 16 gallons. Strong chests, 

 of a size large enough to accommodate a 16-gallon tank, are used for 

 shipping; the hinges and hasps of these chests are riveted on; handles 

 are screwed on at the sides, and each chest is furnished with a strong- 

 lock. The chest may contain one IG-gallon tank, or two of 8 gallons, or 

 four of 4 gallons, or one of 8 gallons and two of 4 gallons, as may best 



