86 SALMON. 



occasionally mature their ova as the males do their milt? Mr. Shaw says that solitary instances 

 have occurred of large female parrs having been found in Salmon rivers with the roe con- 

 siderably developed, "and I find," he adds, "by detaining the female smolts in fresh water 

 until the end of the third winter, that individuals are found in this comparatively mature 

 condition." 



Without denying the possibility of the female smolt partially maturing the ova, it must 

 be admitted that no case has been brought forward in which a female smolt has been shown 

 to have ova fully developed and ripe for impregnation. Even if such an instance should ever 

 be proved, it does not follow that the parr is a distinct fish. The large parr, nine or ten 

 inches in length, occasionally found in rivers, are simply the young of the Salmon, which, 

 not being ready for migration at the usual time, had remained for another year in the fresh 

 water of the river, and feeding, as we know they do, voraciously in this stage, it is possible 

 that a female smolt may occasionally partially develope the ova. 



As to the length of time during which Salmon-fry remain in the rivers before they 

 descend to the sea, it would appear from experiments made at Stormontfield, on the Tay, in 

 1853-4, that there is, in this respect, a great amount of variation even amongst individuals 

 living under the same apparent conditions ; it seems that a considerable number of young 

 fish descend to the sea when they are about fifteen months old.* A parr hatched in February, 

 1878, say, maybe ready to take its journey seawards in Mayor June, 1879; it has also been 

 shown that a large number remain in the river till they are a little over two years old; a 

 parr hatched in February, 1868, may remain in the fresh water till May or June, 1870, and I 

 suspect that this is usually the case. 



The young Salmon after remaining for some time in the sea returns to the river; it is 

 then called a grilse. How long does it remain in the sea before it returns to the fresh-water? 

 In experiments made at Stormontfield, a great number of smolts were marked by cutting off 

 the adipose fin, others by cutting the tail, and others by the fixing of silver rings. Between 

 twelve and thirteen hundred smolts were marked by cutting off the adipose fin and turned out 

 of the pond the first year, of these twenty-two are stated to have been caught as grilse that 

 same season; of those that left the pond the second year eleven hundred and thirty-five were 

 marked by cutting the tail, and of these several are reported to have been caught as grilse 

 in the course of their season. "Of all the smolts marked by the attachment of rings or other 

 effective means," says Mr. Russel, "whether in the Tay or other rivers, none have been got, as 

 either grilse or Salmon, tlie first year, and several have been got the second year. Of the Stor- 

 montfield smolts of the second year — descending in spring, 1856 — three hundred were marked 

 by silver rings, and of those none were got. It is quite possible indeed that all of the three 

 hundred that escaped their enemies in the sea, or even, we will suppose, the entire three 

 hundred, 'no wanderer lost,' may have returned to the Tay as grilse that season, and yet 

 none of them have chanced to be caught. But from other quarters we have what seems 

 positive evidence in favour of the second season. 



In various years a great number of Tweed smolts were marked by a silver wire passed 

 through and fastened to the back part of their tails ; none of them were got as grilse or 

 Salmon the season they were marked, but the next season several of them were caught as 

 most indubitable grilses. Still later experiments on the Tweed, apparently on a smaller 

 scale, but conducted with great care, have brought out the same results. The Duke of 

 Roxburghe has preserved in his possession a fish which was marked as a smolt by the 

 insertion of a peculiarly shaped wire on the 14th. of May, 1855, and which was caught on 

 July 2 1 St. of the folloiving year as a grilse weighing six pounds and a half The more 



* I do not believe, as some have maintained, but never proved, that a 3-oung fish ever grows so fast as to be 

 able to descend to the sea in the same year as that in which it was hatched. 



