Translation Series No.1211

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of the scales. Generally we used a binocular microscope at a magnification of
40 to 150, but we have now switched to a scale projector “BT, Krauss,
Paris).
5.2.1. The arrangement of the scales
In order to answer the question of where the first scales are
being laid down on the body of a salmon, we have examined samples from 40
positions on one side of the body of a salmon (Fig. 30)..With the aid of
a scale projector we measured the radius from the centre to the uppermost
margin of the scale (Fig. 31). It is found that the largest scales . are
situated in the anal region closely below the lateral line. There is prob-
ably the initial zone of scale formation. The next smaller scales are to
be found in a band that extends from there below the lateral line as far
as the pectoral fin. After this follow the dorsal and ventral regions of
the body. The last scales are developed in the regions of the nape and of
the throat, as well as at the stem of the tail.
IBM Schuppenradius 92-M0 % der eel) fen Schteen
= radius of = of the largest
saie
85 - 92% sa l es
75 - 85%
50- 75%
25 - 50%
Fig. 30. The size distribution of
• the scales on the body of the
salmon.
In the largest scales the radius is almost four times as •
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