of the Fishery Board for Scotland. 



as up to the time of leaving the river their feeding has been affected by 

 purely local conditions, such as the supply of food, the weather, and 

 also perhaps by the age and characteristics of their parents, so that in 

 taking specimens from fish congregated in the estuary we are somewhat 

 handicapped by their variety and our ignorance of their original habitats. 

 The arrangement of the lines on the scale is a more reliable guide than 

 the numbers, as in summer, when food is plentiful, they are generally 

 wider apart than in winter, when food is scarce, and the feeding of each 

 season is often distinctly shown by the alternating series of differently 

 spaced lines. 



Notwithstanding the difficulties in arriving at a correct conclusion, I 

 shall give in the following Tables the results of my examination of the 

 scales of parr and smolts of Sal/mo saiar, but wish the work to be regarded 

 as only experimental and requiring further investigation : — 



(1) Parr — 1 year old and younger. 





Length. 



Number of Lines on Scale. 







Date. 















Where 



Remarks. 



Cm. 



Inches. 



Total. 



1st 

 Year. 



2nd 

 Year. 



3rd 

 Year. 



Captured. 



Nov. 1905 



6' 

 6-9 



2^ 



5 to 9 



5 to 9 







1 



f Scales rather 

 -J immature, but 





2f 



5 to 8 



5 to 8 









^ growth good. 



Dec. „ 



5j4 



21 



8 to 10 



8 to 10 









Small growth. 



Jan. 1906 



5-3 



2| 



5 to 9 



5 to 9 























► Tidal water. 



( Scales very im- 

 | mature and 



Feb. „ 



4-6 



If 



3 to 5 



3 to 5 







J barely over- 

 | lapping, with 

 | ridges indis- 

 L tinct. 





4-8 



1* 



3 to 6 



3 to 6 







! 



J 



Mar. ,, 



5-5 



2i 



5 to 7 



5 to 7 











The ridges on the scale completely surround the centre of growth, and 

 are well defined on both the anterior and slightly elongated posterior 

 areas. The membrane protecting the scale is thick in all these young 

 fish. The two parr taken in February were remarkably small, with 

 undeveloped scales, and it is difficult to account for these backward 

 specimens being in tidal water at this season of the year, unless they 

 had descended in search of food. 



(2) Parr — commencing their Second Year. 



Date. 



Length. 



Number of Lines on Scale. 



Where 

 Captured. 



Remarks. 



Cm. 



Inches. 



Total. 



1st 

 Year. 



2nd 

 Year. 



3rd 

 Year. 



April 1906 



May 1904 

 1905 



5- 6 



6- 8 



5- 7 



6- 8 



H 



2| 



12 

 11 

 9 

 12 



10 



9 

 6 

 9 



2 

 2 

 3 

 3 





j> Tidal water. 





In April and May the new growth of the second year begins to 

 surround the scale, and on the anterior margin the ridges are not so 

 close together as those put on during the preceding winter months, 

 and only a few of them continue round the posterior area. 



