Tank No. 21. 
13 
relations, but in life shows on its surface the largest only of its numerous 
holes; over all the rest the dark, slate - coloured flesh forms a con¬ 
tinuous film. It is obtained by diving, dredging, or harpooning with a 
long trident; the principal markets are at Trieste and Paris. Of the 
different kinds the finest and most costly is the Levantine sponge [Eu¬ 
spongia officinalis ) which, in its varieties, extends on all the eastern 
Adriatic and Mediterranean shores. It is not found west of Naples, and on 
the Italian coast no sponges occur in remunerative quantity; though quite 
recently some beds have been discovered 
near Sicily. The harder Zimocca sponge 
[Euspongia zimocca), from Asia Minor 
and Egypt, fetches about one tenth of 
the price, as does the large coarse "horse- 
sponge” (Hippospongia equina ), found in 
all the Levant and extending along 
Africa to the Straits of Gibraltar; it is 
honey-combed with wide holes. Of the 
last genus f Hippospongia) are the Ame¬ 
rican "glove sponge” and "sheeps-wool 
sponge”; their "hard-head” is related to 
the European "Zimocca”, while their 
"velvet sponge” and "grass sponge” are 
independent species. The Bahamas and 
Caribbean sea form the American sponge- 
field. — After the removal of the soft parts of the sponge the fishermen 
usually fill the skeleton with sand, so as to increase its weight and thus 
to obtain a higher price for their goods. For this reason it is necessary 
to rinse newly bought sponges repeatedly so as to remove all foreign 
matter, and it is well at first to add a little hydrochloric acid to the 
water. The sponge of commerce is found rarely in the Bay of Naples. 
It chiefly frequents rocky coasts and coral reefs; it does not live in very 
deep waters, where its elastic skeleton is of no use, nor in cold ones, 
where we must suppose that the material composing it cannot be formed. — 
Mutilation injures a sponge but slightly; divided with a sharp razor even 
the smallest fragments retain their life. After a time they may die, 
and without doubt they suffer from the absence of the remainder of the 
cooperative body; under favourable conditions, however, they will live 
and grow. Ignorant opposition of the fishermen has prevented this pro¬ 
perty from being practically used. 
Note. — Animals and Plants. The Vegetables, adapted to live 
on gases and salts, and the Animals, adapted to live on vegetables and 
on each other, are supposed to have arisen as two well-defined groups 
out of the lowly forms of earliest life. The earliest living things 
cannot have been exactly animal, for there was nothing to eat; but they 
need not have been exactly vegetable. Among the microscopic organisms 
even now existing there are several which many biologists hold to be 
not properly classed as either animal or vegetable; an instance of such 
are the much talked-of Bacteria. 
But of the beings of larger size, such as those treated of in this 
Fig. 4. Euspongia officinalis 
attached to a stone. In its living 
state, 1/3 nat. size. 
