SPONGI/DA. 
ARS 
WT 
aN 
69 
MAD 
Wi 
}} 
a 
“fs —* Upp 
We 
Ni 
Fig. 9.—Sponge, half the natural size, attached to its rocky bed. 
with the porous aspect of any ordinary sponge. 
It will be found on 
examination that these pores are of two kinds, the larger ones called 
