20 



apparent oiitside all tlie medallious in tlie zone and thus forms a framework round 

 them and tliat this ground-substance, when several zones occur in a scale, comes 

 to form as if passages, all more or less mutually parallel and forming abrupt and 

 distinct bouudaries between the single zones or rings — is something new, but 

 serves only to make the rings even more distinct. — It is evident that there is a 

 resemblance between the structure of the gadoid scale and the eel scale, and if it 

 is certain that the concentric zones in the former are annual rings, it is undeni- 

 ably most reasonable to cousider that the same holds good in the latter. 



This view harmonises exceedingly well also with what we know of the 

 life and growth of the eel. It is well-kuown that the eel passes the cold part of the 

 3'ear down at the bottom in a kind of resting-stage; as also that it scarcely feeds 

 during this period and its functions and vitality are lowered and reduced. In 



