From time to time it has been asserted, that the function of impregnation of the ova of these fish is performed after the manner of that of the cartilaginous, viz., before exclusion. The instances related in proof are commonly of a vague kind, and such that little credit can be attached to them. Recently a more precise example has been adduced,—how the ova of the trout, taken from the abdomen of the parent fish, and placed in a “running stream” apart, included in a perforated box, in due time were hatched, producing young fish. The particulars of the experiment, and the result, were published in the spring of last year, and in more than one of the provincial papers; and Dr Robertson of Dunkeld was named as the institutor and reporter of the trial.