194 EVENINGS AT THE MICROSCOPE. 



each shoulder carries a whorl of finer spines, lying nearly 

 close to the main hair, and scarcely deviating from its 

 general direction. This barbed structure of the hairs is 

 chiefly seen towards their attenuated extremities. 



And now do you ask, — What is the object of this 

 elaborate contrivance, or rather series of contrivances ? 

 I answer, — It is the net with which the fisher takes his 

 food : it is his means of living. You have seen that the 

 animal has no power of pursuing prey : he is immovably 

 fixed to the walls of his castle, which is immovably 

 fixed to the solid rock. He is compelled therefore to 

 subsist on what passes his castle, and on what he can 

 catch as he sits in his doorway, and casts his net at 

 random. 



You saw, also, with what a regular perseverance the 

 casts were made ; and now that you have examined in 

 detail the construction of the net, you are prepared to ap- 

 preciate its fitness for the work assigned to it. Its extreme 

 flexibility, produced by the number of its joints, enables 

 the fingers of the hand, or the threads of the net (which 

 you will), to stretch out and to curl up alternately, while 

 the number of the spreading fingers enables the animal to 

 grasp a comparatively large bulk of water in those curling 

 organs. These, then, form a sieve ; the water passes 

 through the interstices of the fingers, while the tiny atoms 

 of solid matter, or the equally minute animalcules that 

 constitute the food of the Barnacle, are sifted out, and 

 detained by the fingers, which, curling inward, carry what- 

 ever is captured to the mouth. 



But see how greatly the perfection of the instrument is 

 promoted by the projecting hairs with which every one of 

 the numerous joints is beset. These, standing out at right 

 angles (or nearly so) to the direction of the finger, meet 

 their fellows from the joints of the next finger, and, cross- 

 ing their points, fill the interstices with an innumerable 

 series of finer meshes, — meshes of such delicacy that it is 



