14 
Transactions of the Society. 
above and below the lateral line just in front of the anus, where, 
as I have said before, the first scales appear. 
I take the scales from both sides of the body so as to be 
perfectly sure of obtaining the oldest scales, as it might be possible 
that at some time one side had received some injury, and* the 
scales might have been formed again, but would naturally be 
younger. 
The otoliths of the eel are more or less oval, one side is convex 
Fig. 3. 
and the other concave. Marcus compared their shape with that of 
the hand. 
They consist of calcium carborate, and an organic substratum. 
When examined on a background their white slightly bluish 
colour reminds one of Carrara marble. 
Otoliths are easily dissolved by any acid ; and formalin must 
be avoided for this reason, they dissolve with effervescence, leaving 
the organic substratum intact. 
