SALMONID^. 109 



Smaland and Norway. These two races he held to be simply modifications of one 

 species, Salmo alpinus, the ssebling of South Germany of which 8- umbla is a 

 synonym. Holding these opinions which were identical with those of Agassiz and 

 others, he entered his protest against the vahdity of Dr. Giinther's new species, which 

 he deemed as merely so many additions to the synonymy of 8. alpinus. Collett, 

 Norges Fiske (1875), considers all the charr to pertain to one form, so also does 

 Malm, and Morean in his Fishes of Prance (1881) arrives at the conclusion that 

 all the charrs of that country are a single species, 8. umbla, which he considers 

 identical with 8. salvelinus. 



In the Zoological Record of 1864, Dr. GiJnther disputes the possibility of the 

 size of the teeth having any bearing on the food these fish consume, maintaining 

 that such may even be a reason towards instituting a species. However, in the 

 artificial rearing of Salmonoids it has been found that some young do take on 

 cannibal propensities and are furnished with larger teeth than their neighbours. 

 Referring to the size of the eggs Dr. Giinther likewise differs with the Scandinavian 

 zoologists, holding that those who may have a more extensive knowledge of fishes 

 " know that the size of the ova is not only invariably the same in iudividuals of 

 whatever size, but, as far as our experience reaches, is even often characteristic of 

 the species of a genus." Here I must refer to page 105, where I have shown that 

 the size of the eggs may depend on the age of the fish. 



There appear to be three difi'erent main reasons for dividing the British charrs 

 into several species, the colour, the number of vertebrse, and of the coecal 

 appendages. 



The colours in the charr do not vary to so great an extent as they do in the 

 trout, due to their residing in deeper waters and usually merely ascending towards 

 the surface at night time to feed, while other changes in tint are consequent upon 

 the breeding season. In the Lakes of Cumberland, Westmoreland, and Lancashire, 

 observes Jenyns, this fish in its ordinary state is the case charr of Pennant ; when 

 exhibiting the bright crimson belly which it assumes before spawning, it is called 

 the red charr ; when out of season the spawn having been shed, it is distinguished 

 by the name of the gilt charr. Thompson observed that he had examined in a 

 fresh state charr from Windermere, from Look Grannock (Scotland), and Lough 

 Melvin (Ireland), and preserved in spirits or dry from nine other lakes in 

 Scotland or Ireland. Examinations of these led him to believe that there exists 

 but one species : one, however, that like the 8almo fario is subject to extraordinary 

 variety. In one lake the male fish can at a glance be distinguished from the 

 female either by colour or by the many characters which are comprised under 

 "form." In another, so similar are the sexes in every external character, that 

 without the aid of dissection they cannot be determined. In size we find the 

 species ordinarily attain twice the length and several times the weight in one lake 

 that it does in another, although the area of their waters is of similar extent ; 

 indeed, in some of the largest lakes this fish will be found not to attain near the 

 size it does in some others, which are but pools in comparison ; there are, 

 however, various influences which account satisfactorily for such difierences. 

 In the form of the body again, we find the species, when in equally high 

 condition, to be in one lake herring-like and in another approximating to the 

 roundness of the eel. So manifold are the differences presented by the charr 

 from various localities, that it would be tedious and perhaps useless to point them 

 out in every case. A correspondent in The Field (April 22, 1882), speaking of 

 the white trout of Quebec, observes that the best authorities seem to agree that 

 the sea-trout of the provinces is simply a 8a1mo fontinalis that has migrated into 

 salt water and changed its colour by that means. This leads us to inquire 

 whether we ought to agree with Agassiz, Thompson, and others that the number 

 of species of charr in these islands is limited to one which is subject to great 

 variations in form, in colour, and other characters due to physical causes ? Or 

 should we adopt the theories of those who see at least half-a-dozen species in the 

 British Isles, and anticipate many more being discovered when the lochs of 

 Scotland and the loughs of Ireland have been exhaustively explored ? 



The number of vertebrce. — The six forms described by Dr. Giinther ai-e said 



