224 EVENINGS AT THE MICROSCOPE 



wide angle from the axis of the finger-like filament, and 

 are graduated in length; and what is very striking, as 

 illustrating the exquisite workmanship of the Divine hand, 

 the hairs themselves are compound structures ; for under a 

 high power they seem to be composed of numerous joints 

 an illusory appearance probably, what look like joints 

 being rather successive shoulders, or projections and con- 

 strictions of the outline while 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 toward their 

 attenuated extremities. 



And now do you ask -What is the object of this elab- 

 orate 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 ani- 

 mal 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 de- 

 tail the construction of the net, you are prepared to appre- 

 ciate 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 or to curl up alternately, while 

 the number of the divergent fingers enables the animal 

 to grasp a comparatively large bulk of water in those curl- 

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

 through the interstices of the fingers, while the tiny atoms 



