214 THE OCEAN. 
bright azure; nor the three or four pretty little 
Rudder-fishes (Perca saltatriz, LInn.), which have 
been following and accompanying us for several 
days past. These are amusing little creatures. They 
are about six inches long, yellowish brown, with 
pale spots: they keep close to the stern, in the angle 
formed by the rudder and the counter of the ship, 
the “dead water,” as it is called by seamen. Hence 
they occasionally dart out after any little atom of 
floating or sinking substance which promises to be 
eatable, and then, having either seized or rejected it, 
scuttle back again to their corner, remaining there 
day and night without rest. Nor can we do more 
than glance at the Sucking-fishes (Hcheneis), that 
are swimming around, or have attached themselves 
to the side of the rudder by means of the singular 
oval disk on the head. As this organ is of singular 
construction, so its use in the economy of the animal 
is involved in entire obscurity. The theory of the 
fish being a very slow swimmer, and needing to be 
carried along by others, must have been formed by 
persons who never had an opportunity of seeing the 
Remora alive. I have seen many, and could detect 
no inferiority in their powers of swimming to a 
young Shark of the same size, which they much re- 
semble in general appearance and motion, when in 
the water. There seems to be a perfect vacuum 
formed by the adhesion of the disk, and the external 
pressure, when under water, is of course great. As 
the mouth opens upon the upper surface of the muz- 
zle, owing to the projection of the lower jaw, it 
is possible that this habit may be connected with 
