STRUCTURE AND INSTINCTS. 365 



velocity of its fall, enable it to sink deep beneath 

 the wave and secure its prey, an act which would 

 have been physically impossible if the bird still 

 retained its former buoyancy. Having captured 

 the fish, the gannet again comes to the surface, 

 instantaneously inflates its air-vessels, and soars 

 away with the captured prey with a degree of 

 facility which, had it still maintained its increased 

 density, would have been unattainable. Can any 

 arrangement be conceived more clearly evincing 

 an express design, a design carried out with the 

 most precise and accurate reference to the laws of 

 physics ? Can any design better display the 

 thorough knowledge of those laws which the wise 

 and Beneficent Designer possessed ? 



