n8 



F. DAY : PERIODS OF MIGRATION. 



such was owing to the presence of 'Bull Trout'; consequently, if 

 these latter were destroyed salmon would again flourish ! From 1868 

 to 1872 the annual close time for migratory trout was suspended, and 

 the destruction of these anadromous forms ruthlessly carried on. The 

 amount of trout was soon reduced, their stock was rapidly diminished, 

 but the salmon would not increase, so the massacre was stopped. 

 And now again, in 1885, the Inspector observes of the Coquet that it 

 ' is a much later river than any of its neighbours in the east, but this 

 may be accounted for by the fact that that river is infested by 

 Bull Trout,* whose habits are different from those of the true 

 salmon.' 



The foregoing are instances in which salmon have deserted certain 

 rivers, and which desertion cannot be ascribed to pollution or artificial 

 impediments to ascent, but owing to some as yet unascertained cause. 

 Possibly the numerous drainage works in the agricultural country 

 through which these rivers pass have had some effect in rendering 

 them less suitable than formerly for the residence of these fish, as the 

 surface. water, instead of gradually percolating through the soil, and 

 so by degrees obtaining access to the main stream, is now rapidly 

 carried off in a short period by means of drainage works ; while 

 I have previously alluded to an 'early' river having changed to a 

 ' late ' one, possibly from this cause. 



It has been suggested that along the colder seas of our eastern 

 coast salmon do not remain in the ocean, but ascend the warmer 

 rivers, and consequently do not hang about the rivers' mouths; while, 

 on the contrary, they behave differently along the Atlantic, or on our 

 southern shores. Thus, off the ' late ' river Fowey, Buckland remarked 

 that a larger number of salmon than are due leave the sea and play 

 about the mouth of the river. These fish come in from the north, south, 

 east, and west. They are big fish, from 25 lb. to 30 lb. in weight. 

 They come late in the year. They are very fat, and greatly different 

 in every way from the native salmon of the Fowey. In these warmer 

 seas, with abundance of food, these fish may continue in the sea until 

 compelled by the near approach of the reproductive period to ascend 

 rivers towards their spawning beds, or they may be fish which are 

 sterile for the season. None seem to have been examined on this 

 point, and only vague surmises have been offered. 



* Buckland refers to the Sea Trout of the Coquet as the Bull Trout or Salmo 

 eriox ; from that river I have not as yet obtained a specimen, but presume it must 

 be identical with Salmo trutta, found in all the contiguous rivers ; while this seems 

 the first time that it has been assumed that the presence of migratory Sea Trout in 



a river occasions it to be a late salmon river ! 



Naturalist, 



