272 ZOOLOGY. 



The adhesion of the buckler is chiefly effected by the 

 smooth membrane that margins it; and apparently 

 upon the same principle as that which applies to the 

 leather sucker with which boys amuse themselves. 

 After the death of the fish, and even after the head has 

 been severed from the body, the moist membranous 

 border of this organ adheres to a plane surface with 

 undiminished power: proving, satisfactorily, that its 

 adhesion is partly mechanical, and not altogether de- 

 pendent upon muscular action, or any vital function. 

 The striae on the surface of the buckler are under the 

 control of a complex set of muscles. One can be raised 

 and depressed by the fish, independent of the others, or 

 all can be moved simultaneously and rapidly. Their 

 uses are, to fix the sucker more firmly, to offer resistance 

 in one determinate direction, and, probably, to liberate 

 the sucker from its attachment, by relieving the vacuum. 

 Their resisting power is so strong, that it is impossible 

 to slide the fish off the object to which it adheres, in 

 the direction to which these plates are opposed, although 

 in the contrary direction this may be easily done ; and 

 it is remarkable, that the Remora usually fixes itself 

 with its head presenting towards the anterior extremity 

 of a body moving through the water; thus availing 

 itself of the resistance the striae offer to any impulse 

 directed from the head towards the tail. When swim- 

 ming, the sucking-fish propels itself by rapid lateral 

 movements of the tail, attended with an awkward twirl- 

 ing motion. 



The species is not altogether free from enemies, 

 although it is evidently secure from the ferocity of the 

 shark. I have already noticed, that two of these fish 

 had been devoured by a Round-Diodon, and we took 

 a third dead example from the maw t of an albacore. 



