88 COMPARISONS OF STRUCTURE IN ANIJULS. 



gannets, and tropic birds, which hovered about, 

 and, ii>^ our view, secured ver}?- many as they 

 sought refuge in the air. It Avas a novel sight, 

 not often witnessed during repeated voyages, 

 and afforded much amusement and interest 

 to those who beheld it." 



Such, then, is the wide extent of difference 

 between the pectoral fins of the fisher, and the 

 flying-fish. They present us with two ex- 

 tremes of structure in these organs, and yet 

 how admirably are they in each case adapted 

 to the habits, instincts, and necessities, of the 

 respective animals ! Thus it is that the struc- 

 ture of 'animals gives us a clue to their mode 

 of life, while, on the other hand, organization 

 is illustrated by an investigation of their mode 

 of pursuing prey, and escaping from enemies, 

 of the place they are destined to occupy in 

 nature, and of the minor details appertaining 

 to their history. 



We have noticed the addition of suckers to 

 the feet of various reptiles, enabling them to 

 cling with the greater tenacity to the surface 

 on which they rested ; and among fishes we see 

 a similar provision, but not always connected 

 with the structure of the fins. 



In that strange fish, the Iwmp-sucker, {Cy- 



