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it myself with my son-in-liiw, a medical man. Wo did thia first with the 

 description of the different varieties of the salmonidae and directions given 

 by " Yarrell" for distinj^uishing them, but not being able to come to any 

 decision we went to a fishmonger, and upon carefully comparing it with a 

 full grown salmo salar, concluded that upon the whole it was a salmon or 

 sea trout, Salmo trntfa, of Linnnous. After thia I took the fish to Mr. J. 

 K. Lord, the principal editor of La/id and iratcr, a person fully com- 

 petent to give an opinion, and with whom I had a personal acquaintance. 

 Upon examination Mr. Lord stated his belief that it was a true Salmo salar. 

 I asked him to examine it again, which he did in my presence and with 

 his pocket microscope, when he again stated his belief that it was a true 

 Salmo salar, but said if I would leave him the fish he would take time and 

 give it a more careful examination ; tliis I did, and upon seeing him 

 again he said that he had altered his opinion and thought it was a salmon 

 or, sea, trout. I then told him for the first time that the fish came from 

 Tasmania, and that Dr. Giinther had pronounced it to be a salmon trout 

 Mr. Lord at the same time assured me that he had never heard anything 

 about the fish ur.til that moment, and that his opinion was formed without 

 anj' knowledge of where the fish came from or that anyone had given any 

 opinion about it. He also mentioned tliat at the age of the fish it was 

 most difiScult in his opinion to decide positively to which ofthe two species 

 it belonged. I think it right to mention, that after leaving the fish with 

 Mr. Lord I went to one ofthe largest fishmongers with my "Yarrell " 

 and microscope, and was fortunate in seeing and examining three beautiful 

 sea trout weighing from 1^ to 3^ lbs., and certainly 1 must confess that 

 the teeth on their vomer corresponded exactly with those of your 

 fish. I cannot, however, I must candidly own, make up my mind 

 that it is a salmon trout, because if so it must have been as you 

 "Well know at least 3 years and 5 months old when it was caught, and 

 therefore ought to be half as large again as it is. You will note that Mr. 

 Lord at first, and after a careful examination, pronounced it to be a true 

 salmon. It was not till after a further and more extended comparison 

 that he altered his opinion ; it is, therefore, not to be wondered at if you 

 and Mr. Allport should prove to have formed an erroneous opinion upon 

 so difiicult a point." It is a law of nature that the species and varieties 

 of one given genus of animals resemble one another far more closely in 

 the early stages of their existence, than they do when arrived at maturity. 

 No birds differ more in the mature plumage than ducks, yet there are 

 dozens of species that no naturalist could determine during the first few 

 "weeks of their lives. I do not mean to saj'- that a Tasmanian black duck of 

 a fortnight old could not be distinguished from an English wild duck of 

 the same age, if they were placed in juxtaposition ; but that they resemble 

 one another so closely, that it would be next to impossible to determine 

 to which species either belonged, if examined alone. And no reference to 

 a fully mature duck or drake could be of any service in solving the 

 difficulty. Amongst the large carnivora in the genus felis we find the 

 tiger, the lion, and the panther, each perfectly distinct when full-grown, 

 yet the cubs all exhibit the striped skin, which is only found in the 

 mature tiger, the stripes being lost in the lion, and changed to spots in the 

 panther. Instances might be given from every division of the animal 

 kingdom, but to come to fish, the genus Thyrsites contains two of our 

 commonest fish, the king-fish and barracouta, and no one who has turned his 

 attention to the subject could have any difficulty in distinguishing between 

 them when grown, yet both Mr. Giblin and Mr. Buckland (either of 

 whom it would be difficult to puzzle with a Tasmanian fish), would find it 

 hard to determine the species of one or the other when four or five inches 

 long. From this natural law, it follows that the more closely species ap- 

 proach one another when mature, the more difficult is it to distinguish 



