306 
POPULAR SCIENCE REVIEW. 
tHs reversal of position^ wlien tlie surfaces were brought into 
close contact^ did not seem in the slightest degree to retard 
the healing process^ or to render the adhesion of the pieces 
less firm than when placed together conformably.^^ 
Such phenomena are so different from those which we are 
accustomed to associate with animal existence, that the ques- 
tion may very naturally be asked, ^^If sponges be animals, 
what is the place assigned to them by zoologists 
It is one of very humble rank. I^aturahsts have now sepa- 
rated from the Radiata of Cuvier the minute gelatinous 
creatures, in which animal life is supposed to appear in its 
very simplest aspect ; hence the term Protozoa, by which the 
sub -kingdom is designated. Each humble organism is appa- 
rently homogeneous throughout, and every part seems capable 
of performing every possible duty that the habits of the 
animal require. The Amoeba may be taken as an example. 
The sponge is an aggregation of Amoebce, endowed with the 
power of secreting a framework or skeleton, which differs to 
a remarkable extent in the leading groups. In the sponges 
in domestic use it is principally composed of a substance 
termed Keratose. The soft elastic substance which we use 
in the bath or at the toilet, and term a sponge, is there- 
fore the skeleton secreted by an aggregation of gelatinous 
animalcules. 
The Sponge Trade. — We have had our attention directed to 
the sponge as a living animal ; we have now to consider it 
as an article of trade. We turn, therefore, from the rain 
and mists which at this season (November) surround us, 
and transport ourselves in imagination to the bright skies 
and sunny waters of the ^gean, for there the best sponges 
are procured. To a valued friend who cruised for some 
successive summers in those regions we are indebted for the 
following particulars. 
The craft employed consists of small caiques, carrying six 
or eight men each, and not too large to be easily managed by 
a pair of oars. During the season of the diving operations 
these boats he about the shores at night, moored in some 
creek, and start off to their ground at daybreak, the crew 
fishing, or diving rather, until the sea-breeze sets in about 
noon, when they take shelter in some of the httle nooks 
abounding on the shores of the Archipelago, and soak and 
stamp out the sponges, treading on them to press out the 
animal matter, and bleaching them in the sun. The fishery is 
carried on during the summer months ; and it is only in nearly 
calm weather that the divers can work. The best sponges 
are procured on detached heads of rock in eight or ten 
fathoms water. The littoral sponges, though numerous, are 
