WHICH HAVE NEVEE DESCENDED TO THE SEA. 465 



occasioning dropsy, one is irresistibly led to the conclusion that hybridization had 

 nothing to do with these results, which may reasonably be attributed to the immaturity 

 of the male parrs*. As a further confirmation of this view, parrs in 1881 taken from the 

 same lot were found prolific, but with comparatively few cases of dropsy occurring. 

 Among these 1000 dropsical fish, only about 100 lived out the year. 



Thus the great mortality from eggs of young mothers was during the incubating stage, 

 hut from young males one season older it seems to have shown itself among the fry; 

 passing over another year, we do not lind so great a mortality among the eggs nor 

 disease of the young. Bearing on this I may allude to the ova of American charrs 

 having been milted from a Scotch charr in November 1882 ; one of the progeny gave 140 

 eggs on November 12th, 1881, or a little under 2 years of age. Only six feeble little 

 ones hatched on February 3rd, 1885. At the same time milt was obtained from some of 

 these hybrids and used to impregnate 4500 eggs of Lochleven Trout ; these hatched on 

 February 2nd, but the mortality was large, being upwards of half the eggs, while there 

 were many deformities and some dropsies among the offspring. Males are evidently 

 more matured for breeding-purposes than are females of the same age. I would here 

 advert to a remark I published in 1883 t, that in the fresh waters of India due to 

 indiscriminate net-fishing the young (of many forms of fish) have to be raised from ova 

 of such as are merely one or two seasons old, while the younger the parent the smaller 

 the eggs, and this is probably one mode in which races of fish deteriorate. 



We now arrive at the question, Why is it that Salmon reared in ponds of fresh water 

 or where they are unable to descend to the sea are variously spoken of? Yarrell tells us of 

 Salmon fry being turned into a pond in 1830, and in 1833 several were taken 2 lbs. to 3 lbs. 

 in weight and perfectly shaped, but he seemed to be in doubt whether they could 

 mature their roe in such localities. Easch thought that fish thus imprisoned, if the 

 lake were very large, would attain about the same size as the Salmon in the sea. 

 Dr. Murie has shown that an arrest of growth occurred in an aquarium at the Zoological 

 Gardens among young Salmon kept in restricted areas. 



I have had the opportunity of examining Salmouoids kept in artificial pieces of water 

 of different extents for various periods of time, the results of some of which I propose 

 alluding to as bearing on this subject. 



In October 1879 I received from Mr. J. Carrington, F.L.S., of the Westminster 

 Aquarium, an American charr (Salmo fontinalis) 9 inches long, which had been hatched 

 from eggs sent from Lake Iluron, and which had been reared by the late Mr. Frank 

 Buckland in his tanks at the Horticultural Gardens, South Kensington. This fish of 



* As corroborative of the above view that the milt of these young Salmon-parrs was deficient in marital powers, 

 I may mention that on the same date 1000 eggs of the common Brook-Trout were milted from one of these Salmon 

 parrs which had been dead a few hours. But not a single egg fructified ; only 3 turned white in December, 3 in 

 January, and 15 in February, or a total of 21. On March 12th the remainder were still quite clear, but destitute of 

 any sign of a contained embryo. 



t ' Indian Fish and Fishing.' Great International Fisheries Exhibition 1883 series, p. 27. 



