Scottish Salmon The opening of salmon fishing has coincided with
the publication of a discovery—a conjecture—of no little interest by the Scottish Fishery Board. The Board has been doing much scientific work of high value in tracing the migration of fish (by discs attached to a fin), by microscopic investiga- tion of scales and in many other ways. Mr. Nall and other experts can read the rings on a scale as if they had the key to a hieroglyphic MS. Especially is the succession of periods of the salmon in fresh and sea water written there. The latest investigation concerns salmon on the Tay. It is true of fish in general, certainly of trout in some familiar streams, that their speed of growth is almost in direct proportion to the supply of congenial food. In these Tay salmon it seems that growth in the fish and the supply of food increase from the source downwards, so that the higher up fish spawn the more slowly the young grow ; and migration to the sea depends in some measure on individual development. And Mr. Macfarlane's facts—and theories (Salmon in the River Tay,- H.M. Stationery Office, ls. 3d.), comparing spring and summer fish, are of general as well as local interest.
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