438 EVENINGS AT THE MICKOSCOPE. 



diate interest. On the green and brown mossy sea- 

 weed which covers the rocks on the bottom, you 

 see many white specks clinging to the filaments ; and 

 there are several adhering to the sides of the tank. 

 These are little living shelled animals of the class 

 Foraminifera, and tliese which you see include several 

 species. By bringing your eye assisted by the lens to 

 bear upon one of these latter, you perceive that it is a 

 little discoid spiral shell, of very elegant form, marked 

 with curved diverging grooves. This is the pretty 

 little Polystomella crispa, a fair sample of its class, 

 and though not more than J^-th of an inch in diameter, 

 it is a giant compared with the Arcella. 



There is more however than the shell to be seen ; 

 though so filmy and shadowy that I wonder not at your 

 overlooking it. Extending from two opposite sides of 

 the shell to a distance each way considerably exceed- 

 ing its diameter, you discern fine threads of clear jelly, 

 running out in long points. The power you employ is 

 not sufficient to enable you to resolve their detail : and 

 for this, I will try to secure a specimen for the micro- 

 scope. 



In this other live-box, then, I inclose one of the 

 white specks from the moss-like clothing of the stones. 

 It is, I see, of another species, namely, Polymorphine 

 oblong, but it will answer our purpose equally well. 



At present we see only the shell, the removal of 

 the animal having induced it in alarm to withdraw the 

 whole of its softer parts within the protection of its 

 castle. "We must have a few minutes' patience. 



ISTow look again. From the sides of the opaque 

 shell we see protruding tiny points of the clear sarcode ; 

 these gradually and slowly — so gradually and slowly 



