igog.] The Life History of the Pacific Salmon. 23 



THE LIFE HISTORY OF THE PACIFIC SALMON. • 

 By Professor J. Playfair McMitrrich. 



{Read iStli December, 1909) 



There is probably no group of fishes that has a greater or more 

 varied interest for us than the Salmonidse. The gameness of many 

 members of the group makes them exceedingly attractive to followers of 

 the "gentle art," the abundance with which certain species may be taken 

 and the richness and delicacy of their flesh make them a food supply of 

 great value and of great commercial importance, and, finally, in connect- 

 tion with the life histories of those that are commonly known as Salmon 

 there are many interesting and important problems that have long at- 

 tracted the attention of scientists. 



The family contains two well-marked groups or sub-families, one of 

 which includes the White-fish, the Ciscoes, and the interesting arctic 

 Stenodus or Inconnu. This group need not be further considered at the 

 present time. In the second sub-familv, that of the Salmoninae, are 

 included a number of forms which are popularly known as salmon, trout, 

 or by combining these two names, as salmon-trout, and it is certain of 

 the Pacific Coast forms of this sub-family that I wish to consider in the 

 present paper. It may be well, however, first to. call attention to the 

 principal Salmoninae that occur on this continent. 



The typical representative of the genus Salmo is the Salmo salar or 

 Atlantic Salmon, which inhabits the North Atlantic and, at the spawning 

 seasons, enters many of the rivers of northern Europe and also many of 

 those of the eastern coast of this continent, from Cape Cod to Hudson's 

 Bay. This is the well-known Salmon of our Quebec and New Brunswick 

 rivers and to the same species are to be referred as varieties certain forms 

 which have become permanent residents in freshwater lakes, such as the 

 Land-locked Salmon of Sebago Pond, and the Ouananiche of Lake St. 

 John. 



This species does not occur on the Pacific coast, but closely related 

 to it, although by some authors regarded as representatives of a subgenus 

 or even a distinct genus, are the black-spotted trout of that region. Of 

 these three species are usually recognized, although there is great variation 



