108 Mr Shaw's Experiments and Observations on the Parr, 



organs of the female of the same age, arc facts on which I could 

 not at present venture an opinion. However, from the specimens 

 which I have at present in my possession of tlie parr three years 

 old, that is, one year after assuming the dress of the salmon-fry, as 

 I have already described, I am prepared to shew that it is not a 

 mature fisli, as it continues to increase in size at about the same 

 rate it did previous to its disposmg of the milt, that is, at the 

 rate of three inches in twelve months, it being now nine and 

 a half inches in length.* I have found this rule to hold good 

 in regard to the growth of the parr, from observations on various 

 individuals found in the river Nith. Assuming the parr to be one 

 inch in length on its first exclusion from the ^gg, or rather from the 

 gravel in which the Qgg is deposited, it will be found to measure at 

 the same period the following year three and a half inches, and 

 when two years old it begins to be distinguished by the peculiari- 

 ties of the salmon-fry, and measures six inches. I do not mean to 

 assert that the size of the Nith parr is to be the rule for other 

 rivers, but as the parr in all rivers is admitted to be identical in 

 species, a corresponding rule will be found to hold good, what- 

 ever stream the fish may inhabit. I have found the male parr on 

 the streams in the winter during the time the old salmon were en- 

 gaged in'depositing their spawn, and on one particular occasion 

 in January last, I caught upwards of three dozen of them. On 

 examination I found these to be all males, and as they were all 

 congregated on the bed or red which the salmon had formed, 

 there is no doubt they were there for the purpose of feeding on 

 the ova as well as the aquatic insects dug up by the female sal- 

 mon, both of which I found in considerable quantities in their 

 stomachs ; but why there were no females found among them, 

 appears to me very mysterious, as they are certainly to be found 

 in other parts of the river the whole season, in pretty equal 

 numbers to the male. I have had, on three different occasions, an 

 opportunity of witnessing the return, or rather first migration, 

 of the salmon-fry to the sea in small shoals. The first of these 

 was in the first week of May 1831. I at that time had an op- 

 portunity of deliberately inspecting them, as the several shoals 



• As this fish oufrht to have been in the sea twelve months ago, it cannot 

 be expected to continue increasing in growth in its present artificial situa- 

 tion. 



