38 THE HAUNTS OF LIFE 
sponge body to a city like Venice, which is 
traversed by canals, bringing in food and use- 
ful materials, and carrying away waste. For the 
sponge’s body is traversed by inhalant canals, 
bringing in food and oxygen (both carried by 
the water), and bearing out useless particles 
and waste products. The water, as we have 
said, passes in by minute pin-prick holes all 
over the surface of the sponge; it passes out by 
the large openings often about the diameter of 
alead-pencil. If a glass tube be carefully fitted 
into one of these exhalant apertures, and one 
need not be afraid of hurting the sponge, the 
water will be forced up into the tube above 
the level of the surface of the pool. Where 
does the force come from? The pressure is 
due to the ceaseless activity of lash-bearing or 
flagellate cells, situated in chambers at the 
junction of the inhalant and exhalant canals. 
On their lashing the whole life of the sponge 
depends. Does it not work hard for its living? 
The sea-anemones nestling in the niches of 
the rocks, some of them like chrysanthemums 
when spread out, how do they get their food? 
They wait for creatures, e.g. small crustaceans, 
to touch their expanded tentacles, which are 
covered with explosive stinging-cells and 
