246 SAMLET, OR PARR. 



against these it was urged that it must be held uncertain 

 whether the roe thus removed had all been shed by the same 

 species; and also whether the strange, and perhaps unnatural, 

 circumstances in which they had been placed, and which Mr. 

 Shaw allows to have been different so far as the important 

 point of temperature was concerned, and probably as regarded 

 food also, may not have materially influenced the subsequent 

 appearances and habits. And these doubts will appear to be so 

 much the better founded, since from some of these experiments 

 it has been concluded that the Sea Trout and Bull Trout are 

 the same species with the Salmon; the contrary of which is 

 admitted by every student of nature. 



But this probable mingling of the eggs is not the only, nor 

 even the principal cause of the confusion in which the subject 

 has been involved. It is known that in the early stages of their 

 existence the young of several species of this family bear so near 

 a likeness to each other, and especially in what must in this 

 case be regarded as the important character of a series of dusky 

 bands along their sides, that eminent naturalists have declared 

 their inability to distinguish them. It is only at somewhat 

 distant periods of their growth, and not by merely an increase 

 of size, that specific marks of their individual nature make their 

 appearance, and others disappear; and these changes may be 

 hastened or greatly delayed through the operation of circum- 

 stances, which hitherto appear to have been little understood 

 or thought of; and Ave are again given to see a source of some 

 of the fallacies adopted from experiments that have been made, 

 by collecting together the young fishes of similar appearance 

 in a river, and setting a mark on them by cutting off the 

 adipose fin, or punching the gill-covers; with the view of 

 ascertaining, not only whether after their migration they return 

 to their native stream, to which extent the trial has been 

 successful; but also as regards the sameness or diversity of the 

 species; in relation to which inquiry the want of discrimination 

 at the outset has of course been fatal. 



But Avhilst these experiments have failed to establish the 

 opinion they were at first believed to support, the more carefully 

 laboured observations of Mr. Shaw have been trusted to in 

 support of the belief, that the fish known by the name of Parr 

 is no other than a particular stage in the growth of the Salmon; 



