346 THE ZOOLOGIST. 



10,000,000 in the Severn, it is estimated that between 50 and 

 75 per cent, of the Alevins pass into the Fry stage, thus bringing 

 the quantity to about 700,000. " In the Fry and Samlet stage 

 the mortality increases to what degree is mere guess, as there is 

 little, if any, evidence ; but the mortality must be 50 per cent., 

 so that there would be 350,000 Smolts. Among the Smolts 

 there is also a very high rate of mortality, say, at least 75 per 

 cent., so that the fish that reach the Grilse stage would be some- 

 thing like 40,000 out of 10,000,000 ova, or 4000 per million, 

 about 4 per cent."* In Kamschatka the Salmon have probably 

 fewer enemies, as the rivers literally swarm with them ; and 

 Guillemard refers to one " little village " where, during the 

 season, " 20,000 fish would be no uncommon catch for a single 

 day."t The same author describes his impressions when standing 

 on the banks of a little branch of the Avatcha River, not more 

 than eighteen inches deep. " Hundreds were in sight, absolutely 

 touching one another, and, as we crossed the river, our horses 

 nearly stepped upon them. Their back-fins were visible as far 

 as we could see the stream, and aground and gasping in the 

 shallows, and lying dead or dying upon the banks, were hundreds 

 more. . . . The millions of fish that are caught, and form the 

 food throughout the year of almost every living creature in the 

 country, are, however, as nothing compared with the countless 

 myriads that perish naturally." \ Krashenniker, writing more 

 than one hundred years ago, says : — " The fish come from the 

 sea in such numbers that they stop the course of the rivers, and 

 cause them to overflow the banks, and when the waters fall there 

 remains a surprising quantity of dead fish upon the shore, which 

 produces an intolerable stink." Guillemard considers that the 

 vast majority — practically all, in fact — ascend the streams to 

 spawn, and, having once done so, die. In the case of some 

 species every fish appears to perish ; in others a few get back to 

 the sea.§ Besides other enemies, when Salmon are abundant 

 and lie close a dreaded disease makes its appearance. This 

 shows as a white fungus about the head and shoulders, and 

 gradually spreads until the fish sickens and dies.j) The female 



* ' The Life of a Severn Salmon,' p. 11. 



f ' Cruise of the Marchesa,' 2nd edit. p. 68. J Ibid. p. 73. 



§ Ibid. p. 92. 



|| John Watson, ' Sketches of British Sporting Fishes,' pp. 3-4. 



