But that which naturalists have been unable to accomplish, has, so far as concerns the two invaluable species just alluded to, been achieved by others with no pretension to the name; and we now propose to present our readers with a brief sketch of what we conceive to be the completed biography of salmon and sea-trout.  In stating that our information has been almost entirely derived from the researches of practical men, we wish it to be understood, and shall afterwards endeavour to demonstrate, that these researches have, nevertheless, been conducted upon those inductive principles which are so often characteristic of natural acuteness of perception, when combined with candour of mind and honesty of purpose.  We believe it to be the opinion of many, that statements by comparatively uneducated persons are less to be relied upon than those of men of science.  It may, perhaps, be somewhat difficult to define in all cases what really constitutes a man of science.  Many sensible people suppose, that if a person pursues an original truth, and obtains it—­that is, if he ascertains a previously unknown or obscure fact of importance, and states his observations with intelligence—­he is entitled to that character, whatever his station may be.  For ourselves, we would even say that if his researches are truly valuable, he is himself all the more a man of science in proportion to the difficulties or disadvantages by which his position in life may be surrounded.

The development and early growth of salmon, from the ovum to the smolt, were first successfully investigated by Mr John Shaw of Drumlanrig, one of the Duke of Buccleuch’s gamekeepers in the south of Scotland.  Its subsequent progress from the smolt to the adult condition, through the transitionary state of grilse, has been more recently traced, with corresponding care, by Mr Andrew Young of Invershin, the manager of the Duke of Sutherland’s fisheries in the north.  Although the fact of the parr being the young of the salmon had been vaguely surmised by many, and it was generally admitted that the smaller fish were never found to occur except in streams or tributaries to which the grown salmon had, in some way, the power of access, yet all who have any acquaintance with the works of naturalists, will acknowledge that the parr was universally described as a distinct species.  It is equally certain that all who have written upon the subject of smolts or salmon-fry, maintained that these grew rapidly in fresh water, and made their way to the sea in the course of a few weeks after they were hatched.

Now, Mr Shaw’s discovery in relation to these matters is in a manner twofold; first—­he ascertained by a lengthened series of rigorous and frequently-repeated experimental observations, that parr are the early state of salmon, being afterwards converted into smolts; secondly,—­he proved that such conversion does not, under ordinary circumstances take place until the second spring ensuing that in which the hatching has occurred, by which time the young are two years old.  The fact is, that during early spring there are three distinct broods of parr or young salmon in our rivers.