G. GENERAL NATURAL HISTORY AND ZOOLOGY. 321 



supposed to be pining for the fresh water. It was, however, 

 still retained in the salt water ; and in May it recovered its 

 appetite, and fattened up greatly without increasing in size. 

 In September it again refused food, and by the middle of 

 February, 1875, had dwindled away considerably in size and 

 condition. Afterward it began to feed again, devouring a 

 whole herring, chopped up for it, at a single meal. 



The fish did not grow very much during the jeav 1875, 

 probably requiring a larger range of water for its proper 

 condition. The inferences derived by Mr. Lee from these 

 facts are that smolts, going to the sea, weighing two ounces, 

 or thereabout, return from their first migration as grilse in 

 a little more than a year, weighing from three to five pounds ; 

 that they can exist for at least three years in the sea without 

 ascending a river, although probably a return to the latter 

 is necessary for its continued and more healthy growth. 

 He also concludes that from the end of the first vear to that 

 of the fourth they feed more heartily and grow more rapid- 

 ly, and are in better condition at one season than another. 



Mr. Lee also remarks that the salmon never takes its food 

 below the plane of its own position in the water, and that 

 when shrimps and portions offish are thrown into the tank, 

 it will rise to meet them as they sink toward it, but will not 

 follow any portion that has sunk below its level, nor will it 

 feed on the bottom, in this respect being very different from 

 the sea trout in the same tank, which rummage along the 

 bottom for food, and pick up shrimps and pieces offish lying 

 there. 



THE RAIXBOW FISH. 



The peculiarities in the nesting and hatching out of the 

 eggs of fishes constitute one of the principal elements of in- 

 terest in their study, and almost every day some variations 

 from the established method is broug^ht to liirht. One of the 

 most remarkable instances in this respect is that presented 

 by a small fish of the genus ^facroj^us^ found in the marshes 

 and ditches along the Ganges, known in India as the Colisa, 

 and called by the English the 7Xiinboio fish. It is character- 

 ized by its brilliant colors, and by the presence of a long fila- 

 ment substituted for the ventral fins. Some curious facts 

 have lately been given bv M. Carbonnier as to the nesting of 



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