4792 Fishes. 



unity of the organisation in all that ever lived ; the law of serial unity 

 which makes the living and past organic worlds one, and not many. 



Nevertheless, to man, species is everything in a practical sense ; 

 for, although specific character and structure explain but little in 

 the philosophy of zoology, specialities are the first steps which 

 lead to more important inquiries : without this step philosophic • 

 zoology, geology, palaeontology, could not be said to exist : hence 

 the intrinsic and enduring value of the labours of the immortal 

 Cuvier. 



R. Knox. 



Meissen House, Upper Clapton, 

 June, 1855. 



On the Growth of the Salmon, from the Egg to the Adult. 

 By R, Knox, M.D., F.R.S.E., &c. 



All who have angled in such rivers as the Tweed, frequented by 

 salmon, sea trout and river trout, must soon, if they observe at all, 

 have become acquainted with the following facts or appearances : — 



1. That river or common trout, whether large or small, may be 

 readily enough distinguished from every other kind of fish caught in 

 the river; occasionally, though rarely, the young trout may be con- 

 founded, when about the length of the little finger, with a small fish 

 called the parr, to whose history I shall presently advert, but, in the 

 fresh specimen, and with a good sight, the young trout may always be 

 distinguished from the parr. 



2. That these small fish, called parr, are to be found in the rivers 

 frequented by salmon or salmon trout, from the sources to their em- 

 bouchures, and in such rivers only. But the converse of this is 

 doubted ; first, by Mr. Young, of Invershin, who says that there are 

 rivers frequented by parr, into which neither salmon nor salmon trout 

 have ever penetrated ; secondly, although I fished the Tyne, in Scot- 

 land, a great many times, and had it fished for me by skilful anglers, 

 who knew the river well, I never could find a parr ; thirdly, I was pre- 

 sent at the fishing of a stream on the East coast of England (North 

 Riding of Yorkshire), on the estate of Mr. Wharton, near Guisborough : 

 the stream was fished with a net (which took everything), from a 

 mill-dain insurmountable for salmon to the sea, yet no parrs were 

 found : nothing, indeed, was taken but — 1st, sea-trout of various sizes ; 

 2nd, sinolts covered with scales, on their way to the sea; and 3rdly, 



