442 



EVElSriNGS AT THE MICEOSCOPE. 



the surrounding "vvater enters on all sides. Tliese pres- 

 ently unite into slender pipes, "svhich, irregularly niean- 

 dering, are continuallv unitinij into lare^er and yet larger 

 canals ; of which the greater open spaces that you see 

 are the oblique divisions. These have certain outlets, 

 called oscula, on the surface, from which the stream is 

 poured oat that has thus made the grand tour of the 



SECTION OF SPOXGE. 



whole interior. Such oscula^ as you perceive on the 

 remainder of the Jlalichondria, are usually raised on 

 slight eminences ; and resemble, especially when in 

 living action, miniature volcanoes, vomiting torrents of 

 water and granules of effete matter, instead of fire and 

 ashes. 



During life these granules were much more diffused, 

 and formed a considerable portion of the living flesh, 

 the remainder being composed of a glairy sarcode, al- 

 most fluid. Tlic whole was maintained in position by 

 the solid spicula of flint, which you see abundantly in 



