FIG. 



LIST OF ILLUSTRATIONS 



14. Diagram contrasting heads of female Salmon and Sea-trout - - 59 



15. Diagram of gill-covers of Salmon Trout, Grey Trout, and Salmon 



{ajter Yarrell, reversed) -------- 59 



16. Scales of a Sea-trout and a Grilse of equal weights contrasted to 



show different rates of growth - - - - - ■ -02 



[7. Vomer of a Clyde river Trout showing dentition - - - - 63 



18. Vomer of a Loch Lomond Sea-trout showing dentition - - 63 



19. Diagram contrasting outlines of tail of a Tweed " Bull Trout 



and of a Loch Lomond Sea-trout 66 



20. " Bull Trout " (3i lb.) from the River Aln 64 



:;i. Scale of River Aln "Bull Trout" (3! lb.) indicating growth 



similar to that of a salmon grilse 64 



22. " Bull Trout " (8 lb.) from the River Aln 68 



23. Scale of River Aln "Bull Trout" (8 1b.) indicating growth 



similar to that of a small summer salmon 68 



24. A Norwegian "Bull Trout" (8^ lb.) 68 



25. Sea-trout eggs 74 



26. Sea-trout "eyed ova "--------• 74 



27. Sea-trout alevins hatching out 74 



28. Late eggs and early alevins 74 



29. Sea-trout "monstrosities" (after GemtniU) - ■ "78 



30. Scale of a late-descending Sea-trout smolt 102 



31. Scale of Sea-trout indicating a 2-winters' residence in fresh water 



prior to migration 106 



32. Scale of Sea-trout indicating a 3-winters' residence in fresh water 



prior to migration - 106 



33. Scale of Sea-trout indicating a 4-winters' residence in fresh water 



prior to migration - 1 lO 



34. Scale of Sea-trout Smolt indicating a 4-winters' residence in fresh 



water prior to migration - - - - - - - - ; 10 



35. Scale of Sea-trout indicating a 5-winters' residence in fresh water 



prior to migration i^a 



36. Scale of Norwegian Sea-trout indicating a 5-winters' residence in 



fresh water prior to migration 114 



37. A typical Whitling ,l3 



38. Scale of Sea-trout illustrating period spent in the sea after descent 



as a smolt and prior to return as a whitling - - - 122 



