6 EsDAiLE, Results of the Sali/io?i Scale ResearcJi. 



There is rather an interesting difference between the 

 records of the two years 1910 and 191 1 ; the percentage 

 offish which spent 2 and 2+ years in the river and only 

 I +, 2 or 2+ years in the sea is much higher in 191 1 than 

 in 1910. It will be remembered that in 191 1 records were 

 obtained from fish caught in all months of the year, 

 during both the fishing season and the close season, while 

 in 1910 records were taken during the fishing season only. 

 However, even when the records obtained during the 

 close season of 191 1 are not included, there is still a great 

 difference in the percentages, J'^'/..^ in 191 1 and 57% in 

 19 10. Taking into account the drought of the summer 

 of 191 1, it would have been natural to reason that the fish 

 delayed their return to the fresh water, and in this case 

 the percentage of 191 1 should have been lower than that 

 of 1910. However, the excessive heat which accompanied 

 the drought of the summer of 191 [ may possibly have 

 influenced the conditions of life of the salmon while in the 

 sea and caused a hastening of sexual maturity. This is 

 again a question which can only be settled by further 

 research, and a comparison of temperature and percentages, 

 etc., of fish caught in various \-ears would be necessary 

 for this purpose. 



When first this work was undertaken it was intended 

 that a most careful examination of the scales should be 

 made with a view to ascertain the relative number of 

 annuli present in the peronidia of river and sea life. This 

 has, however, been abandoned, as it would have delayed 

 the publication of any statement about the research for 

 at least two years. Quoting from my previous paper (6), 

 the definitions of the terms peronidium and annulus were 

 as follows : — 



"On closer examination it will be found that the 

 inequalities (on the external surface of the scales) are 

 caused bv what have hitherto been called ' lines ' or 



