312 ON AN EXPEKIMENT IN THE KEEPING OF SALMON. 



The average rates of growth per month, from the smolt stage in 

 February and March, 1906, are therefore : — 



For nine months to November 26th, 1906 . . 2*2 oz. per month. 



„ twelve ,, ,, „ 15th, 1907 . . 1-6 „ „ 



,, nine ,, ,, August 20th, 1908 . . F5 ,, ,, 



It only remains to mention that the form whicli the salmon assumed 

 was quite an abnormal one. The silvery colour of the smolts after 

 entering sea water was not retained, but the dorsal region became 

 dark and much spotted. This tendency increased till ultimately 

 the greater part of the region above the lateral line was much dark- 

 ened and the spots increased in size and in number, extending over 

 the whole length of the body, and in places considerably below the 

 lateral line, being especially large and prominent about the head 

 and gill-covers. The accompanying figure (Plate XXIV.) illustrates 

 these points in the female, weighing about 4 lb., which died on 

 August 20th, 1908, the date on which the remainder of the salmon 

 were liberated. The flesh of this fish was found to have no appear- 

 ance of the normal " salmon " colour, but was of a pale brownish 

 white. 



