FEEDING IN FRESH WATER. 35 



of their stomachs empty. It can hardly be inferred from this fact, that the dogfish was 

 for any reason abstaining from food, if it were available. The probabihty is that the 

 food is rapidly digested, and only those which have recently ingested food are found to 

 contain it. Having ascended rivers toward their breeding places and near breeding time 

 it is a different proposition. 



Feeding in Fresh Water. 



The question whether or not salmon feed during their ascent of rivers is an old one 

 which has given occasion for many lay arguments pro and con as well as much scientific 

 investigation. 



Much of the evidence that salmon feed in fresh water has been based upon the facts 

 that food has been found in fresh-run salmons' stomachs and that they will take bait or 



fly. 



At Basel, some 500 miles up the Rhine, Dr. F. Miescher-Rusch (1883, p. 429-430), 

 professor of physiology at Basel, made observations upon the Rhine salmon the account 

 of which became almost a classic. Having for four years examined the intestines of 

 Rhine salmon, he was forced to the conclusion that the salmon, from the time they 

 ascend the river from the sea until they have finished spawning, never take food, and 

 that, as a rule, they do not take any food afterwards. He stated that occasionally he 

 found a small stone, a piece of a blade of grass, or a stalk of some plant, which had been 

 swallowed. Once a tolerably large larva of an insect was found in the small intestine, 

 but entirely undigested and intact. He also decided that, with the exception of the bile, 

 no effective gastric juice is secreted. 



On the lower Rhine an examination of 2,000 salmon by Hoek revealed only seven 

 with remains of food in their stomachs. In Scotland after a number of years of exhaus- 

 tive research Dr. D. Noel Paton (1898) reached the conclusion that salmon did not 

 feed in fresh water. 



The fact remains that salmon seldom take food during their ascent of rivers, the best 

 evidence of which is that seldom is anything of the nature of food found in the stomachs 

 of those caught, and that there is not sufficient food in the rivers to support the number 

 of salmon that ascend them. The general absence of parasites in the intestinal tract of 

 salmon after they have been some time in fresh water has been offered as evidence 

 that salmon do not feed. The foregoing are a few of the specific observations upon which 

 the general assumption that all Atlantic salmon practically cease to feed in fresh water 

 is based; also, which convey some positive evidence that occasionally or in some in- 

 stances food substances are to some extent taken. 



On the other side of the question as late as 1921, The Fishing Gazette pubUshed a 

 communication by R. F. Miles (1921, p. 136) which the editor, Mr. Marston, pro- 

 nounced 'interesting testimony.' Mr. Miles wrote: 'I was very high up the river, say 

 seven or eight miles, where it was so narrow one could almost jump across. Fishing in 

 clear water just below a little fall, I hooked a grUse of about 7 lb. Both I and my gilUe 



