8 ESDAILE, Results of the Sabiion Scale Research. 



name, and since then the term has been appHed to the 

 same elements wherever found, so that I have had to refer, 

 rather illogically, to longitudinal circuli. Perhaps it would 

 be better to call them ' fibrilhe.' " 



Mr. J. A. Hutton, in TJie Field {Z), puts forward a list of 

 English names for the different parts of the scale. However, 

 I propose to keep to the terms "centrum," "annulus" 

 and " peronidium." They have been clearly defined, and 

 by their right use no misunderstanding can occur. It 

 should also be remembered that terms such as those I 

 have put forward are capable of being adopted and under- 

 stood by students of all nationalities whereas English 

 words have not this advantage, and might be mis- 

 interpreted by translation. 



It has been suggested that if there is a true racial 

 difference between the spring and summer fish some indi- 

 cation of this might be shown by the average number of 

 annuli in the peronidia of the two kinds of fish. Such a 

 suggestion, however, does not appear to be supported by 

 the results that have, up to the present date, been 

 ascertained. 



A careful examination of a large number of scales 

 taken from different parts of the same salmon proved 

 that the number of annuli in corresponding peronidia 

 exhibit considerable variation (6). No two scales from 

 the same fish appear to be exactly the same in this respect 

 although there is a greater similarity between scales taken 

 from the same part {e.g., the shoulder or the tail, etc.) 

 than there is between scales taken from different parts. 



To prove, therefore, that there is a racial difference, 

 as regards the scales, between the spring and summer fish 

 it would be necessary to comjjare the average number of 

 annuli in the peronidia of a large series of scales taken 

 from exactly the same part {e.g., the shoulder) of fish of 

 the two kinds. If such a comparison proved that there is 



