Measurements and 'proportions of a Sea Trout. 175 



opercula. There can be no doubt that the Carham detenues are 

 a (migratory species) veritable sea trout (Salmo Eriox or Trutta). 

 Of this I am convinced, and I think, as far as the experiment has 

 gone, it is a proof of the capability of the migratory species to 

 live in fresh water, and to thrive under such adverse circum- 

 stances as want of space and natural food, being frozen up in 

 winter, and almost parboiled in the dog days. Not only did 

 they survive all those changes, but they now compare favourably 

 with their fellows from the sea. This proof of the easy ac- 

 climatization of the migratory species of the river Tweed tends 

 strongly to confirm an opinion I have long held, in common with 

 many other persons, that the Sahno Levenensis is neither more nor 

 less than the Sea Trout, being the offspring of those enclosed by 

 the drainage of the lake and the erection of sluices at the source 

 of the Leven, which effectually prevent either egress or ingress. 

 Supposing the Carham detenues were two years old when 

 taken in their Smolt dress from the river, and weighed 2 oz. 

 each, what might have been expected of them in such a home as 

 Loch Leven, seeing that they have grown to the weight of 2 lb. 

 under the disadvantages of artificial feeding, and an enforced 

 residence of two years in a pond not more than 12 yards square, 

 and in which there is very little current, except where a leader 

 from a small burn enters it at one end ? 



A. B. STIRLING. 



Measurements and Proportions of a Sea Trout from Gar- 

 ham Ponds. 



Inches 



Total length of fish, - - - - 13J ' 



Greatest depth of body, - - - - 2f 



Length of head, - - - - - 2f 



Greatest girth of body, - - - - 6f 



Diameter of orbit and eye, - - - f 



Distance from anterior border of orbit to the end of snout, - f 



Length of maxillary bone, - If 



Greatest width of maxillary, - - - f 



Greatest width of operculum, - - - | 



Greatest depth of operculum, - - - - i 



Distance from nape of neck to dorsal fin,- '- - 3f 



From hinder part of dorsal to origin of mort fin, -, * 3 



