XV. A SUBAQUEOUS CITY. 



NATURA NATURANS. 



" Itself surest and indescribable variety ; it publishes itself in 

 creatures, reaching from particles and spicula, through transforma- 

 tion on transformation, to the highest symmetries arriving at consum- 

 mate I'esults without a shock or a leap." EMERSON. 



ON the same plant with Megalotrocha or Lac'mu- 

 laria, one often, finds small patches of whitish-gray 

 matter, looking to the unassisted eye so very much 

 like the associated groups of these creatures as 

 easily to be mistaken for them, yet no two forms 

 of life, when closely examined, are more dissimilar 

 than are the social Rotifers to this, the fresh-water 

 Sponge, i.e., Spongilla fuviatillis, of which we now 

 write. 



Placing them together in the same zoophyte 

 trough under the microscope, the contrast is seen to 

 be very striking. Instead of a group of active 

 radiating beings in ceaseless motion, we have, to 

 all appearance, a dull cobweb-like mass of opaque 



