282 Mr Barrett- Hamilton, Secondary Sexual Characters 



more advanced stages of which the fish becomes coated with 

 fungus, ulcerated (Lord), and so wasted that it gradually loses 

 all its power of movement and eventually dies, so that in late 

 autumn the water of every Kamchatkan river or lake is polluted 

 with rotting carcases. Such colours and hypertrophies then can 

 hardly be of mere aesthetic or combative use to the fish, and 

 I look on the different tints and metamorphoses of the various 

 species as being caused by the working of the same influence on 

 different constitutions. The point I wish to emphasize then is 

 that the coloration and growth are due to a pathological condition 

 by which both sexes are affected, but the exact nature of which 

 we cannot know until some physiologist or pathologist finds an 

 opportunity of studying the fish in the fresh state. It may be 

 a kind of piscine jaundice accompanied by the hypertrophy of 

 certain organs, or it may be (and this I myself believe) that in 

 the effort to produce as much spawn as possible the whole meta- 

 bolism is so upset that the ordinary excretory organs are unable 

 to do all the work demanded of them, and a last effort is made 

 to get rid of the unduly increased quantity of poisonous products 

 by depositing them in the skin. In an enormous majority of 

 cases however, this effort is unsuccessful, and the fish (with 

 possibly a very few exceptions) perish after spawning. Be that 

 as it may, the nature of the disease does not concern me now. 

 What I wish especially to emphasize is the fact that it is a disease 

 which kills these fish. 



And from the recent investigations of some of the specialists 

 who have worked on this still disputed topic, it seems possible 

 that the nuptial changes of our own Salmon are the outward 

 symptoms of a pathological state which pervades the whole 

 system of the fish with the result that (according to Drs Gullard 

 and Gillespie 1 ) its mucous membrane is in a condition of desqua- 

 mative catarrh, suggesting a cessation of function and associated 

 with the absence of zymogen granules in the pancreas, the fatty 

 condition of the liver, the emptiness of the gall-bladder and the 

 absence of all trace of food, together with a low condition of 

 the proteolytic and diastatic action of the digestive secretions, 

 as ascertained by experiment, and an abundance of bacteria in 

 the gut — the latter phenomena interpreted as being probably 

 due to the diminished activity of the gastric fluids. 



It is not so very hard to see that such a disease and such 

 a death, though fatal to the individual, may in reality be the 



1 Report of Investigations on the Life-History of Salmon (Fishery Board for 

 Scotland, 1898, edited by Dr Noel Parker). 



I am aware that the above conclusions have been directly denied by Dr Alex. 

 Brown (see Zool. Anzeig., 1898, xxi. pp. 514, 517 — 23), but it is hard to suppose 

 that the carefully-made observations above described can have been entirely without 

 foundation, even if they be at all exaggerated. 



