22 ESDAiLE, Scales of three Specimcjis of Salmo salar. 



EXPLANATION OF DIAGRAMS. 



Diag. I. 



Fig. I. Showing the positions from which scales were taken 

 from the lolb. fish caught August ist, 1910. 



Fig. 2. Showing the positions from which scales were taken 

 from the lylb. fish caught February 2nd, 191 1. 



Fig. 3. Showing the positions from which scales were taken 

 from the 261b. fish caught March loth, 191 1. 



Fig. 4. Diagram of the marked eye-piece which was used 

 for the examination of the scales. 



Fig 5. Rough sketch of a scale showing the "long axis" 

 = AB and the " short axis " = AE. 



Diag. 2. Showing the river and sea growth of the scale. The 

 portions of the scale formed in the summer and 

 winter and the extent of the peronidia are also 

 indicated. 



Diag. 3. Showing the areas which have been used to show the 

 variation in the number of annuli on corresponding 

 areas of different scales. These areas, or periods, 

 correspond to the peronidia, except the 3rd Period. 

 This is part of the 3rd Peronidium, but having been 

 formed in the river the number of annuli in that 

 part has been separately recorded. 



Diag. 4. Camera lucida drawings of scales, each being typical of 

 those from the particular positions on the lylb. fish. 

 Figs. 1-7 show scales from Positions 1-7. 



Diag. 5. Camera lucida drawings of scales, each being typical 

 of those from the particular positions on the fish 

 weighing 2 61bs. Figs. 1-8 show scales from 

 Positions 1-8. 



