110 SPONGES 
COLLECTING FRESH “WATER: SPONGE: 
In collecting Fresh Water Sponges, it will be found 
convenient to employ a net in which the outer side of the 
hoop, which should be very strong, is flattened and 
straightened and can thus be used as ascraper. With this 
instrument, sponges can be readily lifted out of the water. 
When collected, they should be kept in separate tin 
boxes or glass jars. Although Fresh Water Sponges may 
be dried, they then lose much of their characteristic form 
and, especially the small branching forms, are best kept in 
alcohol. 
In preserving in alcohol, they should first be allowed 
to drain a little while, then placed in 95 per cent of alcohol 
which must be changed in twenty-four hours, and again if 
the liquid becomes turbid until it remains clear. 
Fleshy Sponges must be placed in alcohol or in forma- 
lin, which I found forms an excellent preservative for this 
class of sponges. Those which I put into a five per cent so- 
lution of formalin last winter(1897) have kept perfectly 
well, their tissues remaining hard. 
