DIFFICULTIES SOLVED. 147 



When Mr Shaw first announced the astonishingly 

 precocious procreative power of the male parr, and 

 asserted that by this means he had impregnated the 

 ova of a large salmon, many doubted, and some pro- 

 nounced it an impossibility. But this abnormal pre- 

 cocity, characterising only the male parr, has been also 

 demonstrated at Stormoiitfield. 



As might have been anticipated, another of the ex- 

 periments there tried has given new proof of the ignor- 

 ance of those who maintain that the ova of the salmon 

 are impregnated, not by an emission of semen, but by 

 actual coition. 



Having denounced the notion of Mr Mackenzie of 

 Ardross and Dundonnell that the salmon and the grilse 

 are fish of different species, we received a communica- 

 tion from that gentleman reiterating his theory, and 

 requesting replies to these queries : " 1. A salmon of 

 6 lb., taken in the Tweed or the Tay 1861, when was he 

 a grilse, and what was his probable weight as such ? 2. 

 Where did the salmon that supplied our fisheries, when 

 it was legal to catch them in November, December, and 

 January, come from, seeing that all the grilses are at 

 that time of the year in the rivers as kelts?" 



The experiment at Stormontfield furnishes a solu- 

 tion of these difficulties, by proving that all the smolts 

 do not return the same season as grilse, but that not a 

 few of them remain in the sea, and do not return to the 

 river until the spring or summer of next season, not as 

 grilse, but as salmon of from 4 to 10 lb. weight. This 

 is the explanation of small spring fish, and also of clean 

 salmon coming to the rivers in winter. In both cases 

 the fish had not returned as grilses, but as salmon. 



One of the difficulties felt at Stormontfield was to 

 discover a satisfactory means of so marking the pond 

 fish that they might certainly be recognised when 

 caught. The first expedient, that of cutting off the 

 dead or second dorsal fin, has alone been found satis- 

 factory. Many hundreds had a silver ring attached to 



