44 



(3.) The parr has 10 parr marks, 11 series of scales below tlio 

 adipose fin, 47 pyloric appendages, and deeply cleft caudal. 



I remain, tV:c., Ac, 

 J. A. Youl, Esq. (Signed) A. Gunther. 



Before considering this letter, I desire to express my sense 

 of tlie great obligation the Salmon Commissioners and the 

 colony are under to Dr. Gi'intlier for the trouble he has, 

 on several occasions, taken to help us to a correct determina- 

 tion of the species of the various salmonoids sent to England, 

 and to state that, whenever I have arrived at a somewhat 

 different conclusion from so able an ichthyologist, it has been 

 from a conviction that we have much to learn on this im- 

 portant subject, which no experiments yet tried in Europe 

 have been sufficient to elucidate. 



First, then, it would appear that in every external feature 

 except colour the large or parent fisli coincided absolutely 

 with the description of the salmon trout (Salmo trutta), but 

 that certain peculiarities of colour, and, on dissection, the 

 presence of only 36 pyloric appendages led Dr. Gunther to 

 doubt whether this specimen would convince the sceptical 

 that one species of migratory salmon will thrive in fresh water. 



But, upon reading Dr. Giinther's own details of his ex- 

 amination, can any one doubt that this parent fish was a pure 

 salmon trout ? And would it not have been amazing had 

 it proved otherwise, for this fish was hatched, not from an 

 egQ laid here, but from one of the English eggs, and, if a 

 hybrid, those who obtained the ova must wilfully and 

 maliciously have played a trick upon all engaged, at great 

 expense,in carrying out the experiment — a conclusion not easily 

 arrived at by those who know Messrs. Toul and Eamsbottom. 



As to the peculiarities of colour : variation in colour 

 amongst fish, even where the circumstances are most favour- 

 able to healthy development, occurs so frequently that no 

 one should be surprised at the peculiarities displayed by this 

 specimen after its unnatural detention in fresh water. With 

 true salmon (Salmo salar), if smolts are detained in fresh 

 water till the season for migration is past, the parr marks 

 reappear. (See Proc. Zool. Soc, 1868, part 2, p. 247.) 

 Before you is a beautiful specimen exhibiting this peculiarity ; 

 it was hatched from one of the English eggs of Salmo salar, 

 and died after having put on the smolt scales twice, and twice 

 returned to the parr markings when the period for migration 

 was past. As many present may remember, when the parent 

 fish sent to England was first placed in spirits the parr marks 

 were scarcely visible, but they became more intense after- 

 wards, and, from Dr. Giinther's description, must have 

 darkened considerably on the voyage. 



