2522 EVENINGS AT THE MICKOSCOPE. 



chisel and hammer to the solid rock, and having cut 

 off some projecting piece or angle, have transferred it, 

 all covered with its stony cones, to the interior of a 

 glass tank of sea-water, for more intimate acquaintance 

 with the little builders at leisure. 



These are Barnacles {Balanidd). Such a colony 

 I have now in my possession, which I will submit to 

 you, for they present a beautiful and highly interest- 

 ing spectacle, when engaged in their ordinary employ- 

 ment of fishing for a subsistence. And not only so, 

 but I have living specimens of a much larger and finer 

 species than the common one, — the Balaniis porcatus, 

 whose castle stands an inch or more in height. Tlie 

 structure, however, and habits are pretty much the 

 same in both. 



"Without disturbing the busy fishers, then, just take 

 your seat in front of this tank, and with a lens before 

 your eye, watch the colony which is seated on that 

 piece of stone, close to the glass side. From one and 

 another, every instant, a delicate hand is thrust forth, 

 and presently withdrawn. Fix your attention on some 

 one conveniently placed for observation. It is now 

 closed ; but in a moment, a slit opens in the valves 

 within the general orifice, displaying a black lining 

 with pale blue edges ; it widens to an oval ; the pointed 

 valves are projected, and an apparatus of delicate 

 curled filaments is thrust quickly out, expanding and 

 uncurling as it comes, to the form of a fan ; then in an 

 instant more the tips of all the threads again curl up, 

 the threads collapse, and the whole apparatus is quickly 

 withdrawn, and disappears beneath the closing valves. 

 The next moment, however, they re-open, and the 

 little hand of delicate fingers makes another grasp, an J 



