294 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 1 

 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 

 appreciate 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 alter- 

 nately, 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 whatever 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, crossing their points, fill the interstices with an 

 innumerable series of finer meshes, — meshes of such 



