bka.-A"nkmonp:s : thktr wKAroNS. 



409 



after anotlier, sucked in, as it were, tliroxigli an imper- 

 ceptible orifice. 



Before the Mhole have disappeared, we will secure 

 a portion for examination. For this end I cut off with 

 a sharp scissors about one-sixth of an inch of the 

 extremity of one of the threads, which now I transfer 

 to a drop of sea-water in the conipressorium. These 

 thi'eads are called acontia. 



Examining this fragment under a low power of the 

 microscope, mo readily see that, thongli at first it 

 seems a solid cylinder, it is really a flat narrow ribbon 



pouTiON OF ACONTiuM (Jlattened). 



with the edges curv^ed in, which can at pleasure be 

 brought into contact, and thus constitute a tube. Like 

 all other internal organs in these animals, its surface is 

 richly ciliated, and the ciliary currents not only hurl 

 along whatever floating atoms chance to approacli the 

 18 



