of the Salmon in Fresh Water. 63 



R CHANGES IN THE WEIGHT AND IN THE CON- 

 STITUENTS OF THE MUSCLES, GENITALIA, 

 AND OTHER ORGANS DURING THE SOJOURN OF 

 THE SALMON IN FRESH WATER. 



<i. CHANGES IN WEIGHT AND CONDITION OF SALMON 

 AT DIFFERENT SEASONS IN THE ESTUAR1KS 

 AND IN UPPER REACHES OF THE RIVERS. 



BY D. NOEL PATON, M.D., F.R.C.P.ED., 



AND 



JAMES C. DUNLOP. M.D.. F.R.C.P.ED. 



Further light is thrown upon the question of whether fish continue to 

 feed in the sea as their genitalia develop, and whether they feed after 

 entering the river, by the study of the differences in the condition of 

 the fish at the mouth and in the upper reaches of the various rivers 

 throughout the season. 



Such an investigation also helps to clear up various problems in regard 

 to the migrations of salmon. If there is anything like a general to and 

 fro passage of the fish from the upper waters to the sea and back 

 throughout the season, then the fish at the mouth and fish in the upper 

 reaches will not be sharply marked off from one another. If such 

 migrations do not occur to any extent, then the fish in the upper reaches 

 may be expected to manifest characters different to those in the estuaries. 



FEMALE SALMON, 1896. 



Table I. gives the length in centimetres, the weight, -weight of mu.sc-U-, 

 and weight of ovaries, both actual and per standard fish, of the female 

 fish examined in grammes : 



[TABLE. 



