202 



THE MICROSCOPE AND ITS LESSONS. 



of the present, had it the power of speech ? " Family," you 

 say ; " then, are there many varieties ? " Very many, and 

 their forms are as different as their numbers are great ; 

 while their fossil remains, strikingly visible in many 

 common pebbles, are deeply interesting to the " pebble- 

 seeker." 



We are told that something like five hundred tons of 



A group of sponges. 



sponges worth more than ^170,000 are annually sold 

 in England alone; the horny skeleton of very lowly 

 organization having around it in its ordinary life a fleshly 

 mass of slimy " sarcode," which, before the mass can be 

 lit for the dealer, must be stripped off. 



Since sponges have risen so enormously in price, 

 attempts have been made to cultivate them artificially by 

 growing them from cuttings. A farm of this sort was 



