76o 



DEPTHS OF THE OCEAN 



fish, and we therefore easily see how the number of annual 

 rings increases proportionately with the growth of the fish. 

 By counting the winter-rings we can ascertain how many 

 winters each fish has lived, and by examining a great number 



Fig. IV 



Fig I Dm Bergen April 1907 

 FigNVVi Bredsund Juli 1907 

 fig vn Hauqsholmen Mars 1907 



Gadusvirens 



Fig. 554. 



Scales of saithe [Gad us virens) of different sizes (size of the fish noted below each scale). 



(From Damas. ) 



of individuals from a definite catch we may ascertain the 

 number of individuals belonging to each annual class. In 

 this way we may obtain an idea of the age-composition of the 

 catch. The next step is to examine a large number of catches, 

 and to form an estimate regarding the age-composition of the 



