— 123 — 
the broad plates represent rapid, the narrow ones slower growth, the growth of the scale 
being in proportion to that of the fish. We can thus, by means of the scales, observe 
the growth which has taken place in the course of a year, the greater, rapid summer 
growth, and the lesser, slow increase in winter. Slightly magnified, the zones correspon- 
ding to the winter’s growth appear as rings, called winter rings. 
Finmarken 70cm. 
\ Bergen „70cm. 
i à 
Bergen 41 cm 
AN 
LA, 
Fig. 79. Graphical view of size of plates on the scales of 4 cod, 
2 from Finmarken and 2 from Bergen (vide text). 
Fig. 79 gives a graphical representation of the varying size of the plates, from the 
centre to the periphery of the scale, in four skrei, two from Finmarken and two from 
Bergen. The vertical distance from a point on the curve to the abscissa indicates the 
width of the plates, magnified 300 times. The summits of the @urves thus indicate peri- 
ods of rapid growth, the hollows between them representing periods of slow growth, 
the deepest hollows corresponding to the winters. The two specimens from Finmarken 
exhibit, on the whole, a slower growth than those from Bergen. 
The number of these indicates the age of the fish, while a study of the size of the 
16* 
