BULLETIN OF THE UNITED STATES FISH COMMISSION. 395 



this time the eggs should be washed bj" perfectly clear running water of 

 even temperature. The least turbidness of the water will cover the 

 outer shell of the egg with a layer of slime which constantly increases 

 in thickness. The egg, which also has a sort of breathing process (ab- 

 sorption ot oxygen and ejection of carbonic acid), is choked thereby and 

 dies. Even a very superficial examination of our shell-lime brooks 

 shows that they do not meet the requirements of the hatching period. 

 They always appear slightly turbid, owing to a fine white sediment, 

 which consists principally of carbonate of lime (with some clay and oxide 

 of iron). The springs of these brooks are generally quite clear and 

 pure, but before they have flowed any considerable distance they be- 

 come more and more turbid. The aquatic plants withdraw from the 

 carbonated lime dissolved in the water part of its carbonic acid, and 

 thereby make it more difficult to be dissolved in water. This sediment 

 of carbonated lime, together with somecky, which by a mechauical pro- 

 cess is carried away from the bed of the brook, produces the unavoid- 

 able turbidness of our waters. Another essential condition of the well- 

 being of trout is that they should not have too many other fish to share 

 with them the natural food contained in the brooks. For this reason 

 (besides the requirements of the hatching period), the trout are found 

 only in the higher i)ortion (near the springs) of our natural water- 

 courses. If pike and other fish get in the streams, some flue specimens 

 of trout will still be found, but no longer large numbers. The conclusion 

 to be drawn from the above observations is simply this, that it will 

 amply repay the trouble to place young trout in suitable brooks in our 

 neighborhood (Frauconia) which are not too strongly i)olluted by refuse 

 from villages, &c. Untortunately the brooks will have to be stocked 

 every year, if a proper stock of flsh is to be obtained, because young 

 flsh from naturally laid eggs will not flourish in these brooks. The first 

 and principal point aimed at should be that the young fish are strong 

 and healthy and carefully hatched in suitable water. Neglect in this 

 respect is probably the reason that many an experiment has proved a 

 failure, and that many a willing heart has been sadly discouraged. 



196 MABTIIV BRAIVDT'S METHOD OF PRESERVIIVG FRESH FI8H 



AIVD OTHER ARTlCIiES OF FOOD* 



The more the fish trade extends to greater distances from the fishing 

 stations, and the more the improved and enlarged fisheries at times 

 overstock the market, does it become the more necessary, in order to 

 avoid losses, not only to preserve the fresh fish bypickling or some other 

 process, but also to prepare them in such a manner that they may be 

 safely stored away until there is a better market. This object has been 



*" May-tin Brandfs Methode zur Konsti'veirung frischer Fische und anderer Nahrungsmit- 

 tel." From the Deutsche Fischerei-Zeitung, Vol. vii, No. 28, Stettin, July 8, 1884. Trans- 

 lated from the German by Herman Jacobson. 



