RECENT RESEARCH UPON SALMON 231 
of their stomachs has been accounted for by a hypothetical 
power of ejecting the contents when they are netted or hooked. 
But to found on such a hypothesis would be childish, seeing 
that the ejecting power cannot be limited to the period when 
the fish are in fresh water, and that the stomachs of salmon 
taken at sea are often found gorged with food. I have 
given below (page 238) some evidence tending to show 
that, should the period between entering the river and the 
maturation of the ovaries be so prolonged as to cause a return 
of appetite consequent upon the necessity for nutriment, the 
fish will revisit the sea before spawning. 
For some time after spawning the salmon remains in the 
river as a “ kelt,” or spent fish. The investigations conducted 
in the Rhine by Dr. Hock and the late Professor Miescher 
Ruesch led them to the conclusion that during this period also 
the digestive tract of the salmon remains functionless, or, at 
most, capable of very feeble action. This has since been con- 
firmed in the course of investigations upon British salmon 
conducted in the Research Laboratory of the Royal College 
of Physicians of Edinburgh in co-operation with the Fishery 
Board for Scotland. The observations of these gentlemen all 
tend to establish the fact that, although traces of food may 
occasionally be detected in the stomachs of spent fish, especially 
after they have reached the tidal water, the true feeding-ground 
of the salmon is the sea, and that it performs a physiological 
fast as long as it remains in fresh water. 
It is to be noted that the conclusions of the Edinburgh 
Committee, as reported upon in 1898,* have been checked by 
an independent biologist, Dr. Kingston Barton, who detected a 
very serious error in one of their processes. The Committee 
were led to believe that, so soon as the salmon entered fresh 
water, its digestive tract underwent a morbid change, described 
as ‘‘ desquamative catarrh,” rendering the organ functionless 
* Report upon Investigations on the Life-History of the Salmon, H.M. 
Stationery Office, 1898. 
