THE SPAWNING PERIOD 169 



to induce them to leave such lochs at all. In the lower basin of Loch 

 Lomond they congregate in great shoals between the lowest island, 

 Inch Murrin, and the outflowing Leven. I have caught one in Loch 

 Lomond, a fish of about 4 lb. in weight, as late as May 24th, and in 

 Loch Ness I once caught one, a small fish, on June 13th. 



When the kelts finally reach the estuary or the sea, they rapidly 

 begin to regain their best condition. I have been able to judge of their 

 progress in this respect from the improvement in appearance, as seen 

 from day to day, of those taken in the estuary sweep-nets of the Clyde. 

 I have no proof that any individual fish has been taken and returned 

 day after day until such time as its condition warranted its being killed, 

 although the netsmen aver that such fish can be recognised. But it is 

 generally obvious that the class of fish got in the nets changes gradually 

 each day for the better through the yield of the net containing each day 

 a higher percentage of kelts which have approached more nearly to the 

 condition of takable fish. 



It would be difficult without specially collated evidence from many 

 rivers to pronounce upon a further question, namely, whether the mature 

 fish, once they have ascended to spawn, return again each year for that 

 purpose. I cannot find any reliable opinion on the point, and I do not 

 pretend that the scanty evidence from marking which I possess is 

 conclusive. I shall recapitulate the evidence in detail. 



In October 1904, the men, when stripping fish in the neighbouring 

 streams to stock Luss Hatchery, marked twenty-one sea-trout with the 

 official labels supplied by the Fishery Board. In October 1905, as 

 many as nine of these marked fish were seen again in the streams, but 

 through an unfortunate misunderstanding the labels were not removed 

 from the fish for purposes of identification. So far the facts point to 

 a return in two consecutive years. But in season 1906 three more of 

 these twenty-one marked fish were recovered as tabulated thus : — 



