128 American Fisheries Society 



the sea to the river conditions or vice versa is never a sudden, but 

 always a gradual process. Sir Herbert Maxwell, Professor Noel 

 Paton, and other well-known writers on Salmon are convinced 

 that they are fresh- water fish, an opinion apparently that also of 

 Mr. Henry Lamond in his fine work on "The Sea Trout," for in 

 his critical remarks on the view of Mr. Tate Regan (of the British 

 Museum) that the Salmonidas "may be regarded as marine fishes 

 establishing themselves in fresh water," he says, "the facts 

 equally point to fresh water as the original habitat of the 

 Salmonidas. In particular, the fact that in salt water the spawn 

 of Salmon and trout cannot come to fruition seems to me to be 

 pertinent. " My own conclusion long ago was that the Salmonidas 

 are marine forms, and the feeding habits and the rigid fasting of 

 adult salmon in fresh water strongly support my view, while the 

 adaptation of the eggs and of the young and immature stages to 

 fresh water conditions can be readily explained. If the Salmon 

 be a native of the ocean, and the fresh water habitat only resorted 

 to for special reasons, how is the remarkable transformation to be 

 accounted for? The evolution of the whales and seals from land 

 forms to aquatic types is hardly more striking and remarkable. 



Does Migration Avoid Sea Dangers. 



Professor L. C. Miall, thirty years ago, hazarded the opinion 

 that salmon resorted to the upper portions of rivers, more or less 

 distant from the ocean, in order that the dangers of the sea-bottom, 

 especially predacious enemies, might be avoided. The eggs and 

 young, it was argued, would be safer in fresh water streams. 

 The force of this contention never appeared to me to be very 

 convincing. Of course the eggs and young of very few fish are 

 found on the sea-bottom. The physical and chemical conditions, 

 the darkness, the pressure, the cold, and especially lack of oxygen, 

 are all unfavorable, and most marine fishes appear to deposit 

 floating eggs, or resort to the shallow waters, close inshore, or 

 even between tide-marks; for in the surface waters, and in the 

 littoral shallows, the necessary conditions for hatching and larval 

 development are best provided, and wind and wave action ensures, 

 as is well known, the richest condensation from the atmosphere. 



