SPONGES 81 
SPONGES IN TIME. 
Looking backward through the past ages, we find 
that sponges began in the lower silurian age, were abun- 
dant in the oolitic and cretaceous periods, as their remains 
testify, and so continued into the tertiary, up to the present 
age. Itis highly probable that the first to appear were 
the Spiculigenous Sponges, for the remains of these con- 
stantly occur, even in the silurian rocks. 
SPONGES IN HISTORY. 
Sponges appear to have been used for domestic pur- 
poses from veryearly times, in fact, the name sponge is de- 
rived, according to Johnson’s History of British Sponges, 
from a Greek word which signifies “ to squeeze”. 
Homer, in the Iliad, alludes to the sponge as an article 
of toilet use, but its scientific history begins with Aris- 
totle. He speaks of three kinds of sponges; one very fine, 
called Achilleum, another hard and rough called tragos, 
and another which was called aplysiae because they can- 
