ADDITIONAL NOTES. 293 



and red gillaroo, in Lough Derg, the former with black spots on 

 it, the latter with red. The white is described as the smallest 

 and the better eating, the size varying from two to twelve pounds. 

 The author, page 55, speaks of the gillaroo as " a sort of link 

 between the trout and charr," from a certain resemblance of 

 stomach. The stomach of the charr, it is worthy of remark, 

 varies, it may be inferred, with the quality of its food ; in many 

 instances I have found it even thinner in its coats than that of 

 the common trout. J. D. 



(On the Salmon and Parr, page 59.) 



Since "Salmonia" was first published, so much additional 

 information has been obtained, respecting the salmon, in its 

 early stage, its growth, and changes, that the question, so much 

 agitated, whether the Parr is a young salmon or a distinct 

 species, may be considered now as satisfactorily solved. 



The inquirers to whom we are most indebted for facts on the 

 subject, are Mr. Shaw and Mr. Young. The conclusions at 

 which they have arrived, the result of their observations, may 

 be briefly noticed. 



According to Mr. Shaw, who took the lead in the inquiry, the 

 parr is a young salmon, or a young sea-trout (distinguishable, he 

 thinks, by certain peculiarities *), which becomes a smolt, or 

 acquires the silvery hue of the adult fish, though remaining of 

 small size, towards the end of the second year of river life, 

 preparatory to migrating seaward. 



According to Mr. Young, the salmon is a fresh-water fish, and 

 is an inhabitant of fresh water, on an average, ten months out of 

 the twelve, descending only to the sea (judging from the effect) 

 for the purpose of that high feeding essential to its growth, and 

 often returning to the river before its ova are developed ; the 



* The smolts of the salmon, and of the sea-trout of the Solway, he states, 

 do not differ in size, but in some respects in colour, most marked in the fins, 

 the extremities of the pectoral fins of the sea-trout smolt being orange, with 

 a tendency to the same colour in the ends of the dorsal and caudal rays, 

 whence this smolt is there called the orange fin. 



It would appear from his observations that the female sea-trout can have 

 mature ova, and breed without descending to the sea, and that a certain 

 number actually do so, without assuming their silvery migratory dress, thus 

 approximating to the common trout. 



