350 ANNUAL RECORD OE SCIENCE AND INDUSTRY. 



well as of the true salmon ; and although fisheries of these 

 species have not yet been established, this result is confident- 

 ly expected in the course of a year or two. The report con- 

 cludes by a lengthened statement of the present condition of 

 the fish-pound question in the state, and commendation is ex- 

 pressed of the existing act of the Assembly, by which all fish- 

 ing by means of fixed nets is to cease after the end of 1871. 

 A compromise, by which the pounds were to be kept closed 

 from Saturday night to Monday morning, was found to be en- 

 tirely inoperative, the fishermen refusing to accede to the re- 

 quirements of the law, leaving no alternative, in the opinion 

 of the commissioners, but the prohibition above' mentioned. 

 Fifth R&port. 



NUTRITION OF YOUNG FISH IN HATCHING ESTABLISHMENTS. 



Dr. Hartmann has lately made a communication to the 

 German Fishery Society in regard to the age at which arti- 

 ficially hatched fish, salmon especially, should be turned out, 

 and where ; and he endeavors to show that very unscientific 

 views have prevailed on this subject, which have resulted in 

 serious loss to the stock. In his opinion about 30 per cent, 

 of the eggs laid by the salmon are not impregnated at all, in 

 consequence of not receiving a sufficient quantity of the milt 

 of the male, and that 10 per cent, of the lay is destroyed by 

 the male fish, leaving 60 per cent, of the whole. As these, 

 however, are exposed to the ravages of small fish, crustaceans, 

 birds, etc., as well as to the dangers from freezing, half are 

 probably destroyed, leaving only 30 per cent, out of the orig- 

 inal number (say 25,000) to keep up the supply. Supposing 

 all these, however, to be hatched, we have then other dangers 

 of equal moment. Thus those remaining have for a number 

 of weeks the yolk-bag attached, and are easily injured by the 

 currents or the sand at the bottom, and are greedily devour- 

 ed by all sorts of aquatic animals; so that our author thinks 

 it is well if, especially in the case of salmon and trout, half a 

 dozen are left alive by the time they are able to swim about 

 and take food for themselves. This is the natural state of 

 things, where no artificial impregnation no*v care is exercised. 

 By proper management, however, eighty to eighty-five fish 

 out of the hundred can be hatched. After the navel-bag is 

 absorbed, the necessity arises of furnishing food in greater 



