METABOLISM OF THE SALMON. 



" " I "HE curious life history of the salmon has always 



X been a subject of the deepest interest not only to 

 the zoologist and physiologist, but also to the sportsman. 

 In spite of the most careful study by scientific investigators, 

 the migrations of the salmon and the various changes in 

 condition that it undergoes are even now far from being 

 fully understood ; and the careless observations and foolish 

 traditions of keepers, fishermen and gillies have only 

 served to involve the matter in a deeper cloud of mystery." 



The foregoing is the opening sentence of a report x which 

 has recently been presented to the Fishery Board for 

 Scotland by Dr. Noel Paton. In order to dispel this veil 

 of ignorance, Dr. Paton has undertaken an extended series 

 of observations, which have been carried out in the Research 

 Laboratory of the Royal College of Physicians of Edin- 

 burgh. The subdivisions of this subject are so numerous, 

 and the points to be investigated so diverse that Dr. Paton 

 has adopted the wise measure of obtaining the co-operation 

 of several other workers in the laboratory. This union of 

 forces has produced a result which would have been beyond 

 the power of any individual investigator. 



The principal subjects of the research consist in a veri- 

 fication of the alleged abstention from food which the fish 

 exercises when in fresh water, the details concerning the 

 growth of the generative organs which occurs during this 

 period, the simultaneous decrease in the muscular tissue,, 

 and the consequent deterioration of the food value of the 

 fish, a discussion on the sources of muscular energy, and of 

 the metabolic exchanges in fats, proteids, iron, phosphorus, 

 pigments and so forth. 



Such an enumeration of the chief subjects treated will 

 indicate the wide scope of the work ; in fact it forms the 



1 Report of Investigations on the Life History of the Salmon, edited 

 by D. Noel Paton, 1898. See also Journal of Physiology, 1898, vol. xxii., 



P- 333- 



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