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Show 38 DR. J. M U R I E O N I R R E G U L A R I T Y [Jan. 13, is not a Salmon. It must be borne in mind, moreover, that in my previous communication I stated that the number of scales counted in the specimen was not rigidly accurate, those given as transversely inclined to the long axis of the body being decidedly under rather than above the precise amount. I say so advisedly; for on reexamining specimen No. 1, and taking a linear row of scales slightly in advance of the point previously chosen, and therefore more in accordance with Giinther's plane of obliquity, I find that twenty-one or twenty-two (?) are definable. But howsoever this may be, the penultimate column to the right of the table here given (p. 37) conclusively demonstrates that, even in limited numbers of scales, the dubious specimens in question agree less with the undernoted species of Salmo than with S. salar. Lastly, this remark applies with still greater force to the scales counted linearly from the lateral line to the ventral fin, with the proviso that those of the lake fishes of mid-Europe are unrecorded. II. Uncertainty of the species.-Upon this point it need only be said that, if not Salmo salar, it is most remarkable, and fatally telling to the denial of parentage, that the fish correspond to none of the European types, either in size, markings, or other distinguishing characteristics. Had therefore a mistake happened as to the recognition of the ova, this would have ultimately rectified itself in the development of the specific characters applicable to adult piscine form. III. The question of hybridity.-As respects hybridity, which Dr. Gunther suggests may be the case with those specimens reared in the Gardens, it becomes rather an important item of deliberation. On what grounds can it be assumed we have hybrid fish to deal with, granting, for the time being, no set line of demarcation proving their identity with a single specific form can be given ? 1. The produce of different species may have been fertilized at the Rhine fish-hatching establishment. 2. Instances of hybrids among certain of the Salmonidae are stated to be of no uncommon occurrence. 3. Our specimens possess resemblances to none of the well-established forms, but have appearances indicating intermediate origin. As experiments prove, the fertilization of the ova of one piscine form with the milt of another distinct species is beyond controversy exemplified in hybrids between the Salmon and the Trout. It is needless therefore to shirk the reasonable contingency of intermixture of breed having accidentally or intentionally supervened. Against such a circumstance it can be advanced that, so far as is known, the authorities at Huningue did not with intent form a cross breed and transmit the impregnated ova of such to this country as pure Salmo salar. Moreover, to the practised eyes of Buckland and Bartlett, the ova were those of Salmon; and the period of hatching coincided with that of that fish rather than with that of the Great-Lake Trout, Charr, Salmon-trout, or Common Trout, received in the beginning of the same year, 1863. This fact also tends adversely to the presumption of accidental hybridity. |