Chap. 69.] 
SPONaES. 
455 
thick, very hard, and rough, and are called tragi r""*^ the 
second, are thick, and much softer, and are called mani 
of the third, being fine and of a closer texture, tents for sores 
are made ; this last is known as Achillium."^^ All of these 
sponges grow on rocks, and feed upon'*^ shell- and other 
fish, and slime. It would appear that these creatures, too, have 
some intelligence ; for as soon as ever they feeP''' the hand 
about to tear them ofi*, they contract themselves, and are sepa- 
rated with much greater difficulty : they do the same also 
when the waves bufiet them to and fro. The small shells that 
are found in them, clearly show that they live upon food : 
about Torone*^ it is even said that they will survive after they 
have been detached, and that they grow again from the roots 
of sponges, but that Pliny here is only enumerating those which were em- 
ployed for domestic use. 
In the singular, tragus," from the Greek rpayo^, a goat, on account 
of their strong smell, which they contract from the mud and slime in which 
they are found. 
Probably from the Greek /jluvoq, "rare,'* "in small quantities;" in 
allusion to the comparative rarity of this kind of sponge. 
A term merely used, as Caelius Rhodiginus says, to denote the strength 
of its texture. 
Cuvier says, that though sometimes shells and small animals are found 
lodged in the sponge, they do not afford it any nourishment. Having no 
mouth, it can only live and increase by the inhalation of substances dis- 
solved in the water of the sea. 
^"^ " Sensere." Cuvier says, that many observers have stated that this is 
the only sign of animal life that the sponge affords ; but that Grant assures 
us that it does not even afford that. The fact is, however, that " the sponge 
itself is a cellular, fibrous tissue, produced by small animals, almost imper- 
ceptible, called polypi, and living in the sea. This tissue is said to be 
covered in its native state with a sort of semifluid thin coat of animal jelly, 
susceptible of a slight contraction or trembling on being touched ; which, in 
fact, is the only symptom of vitality displayed by the sponge. After death, 
this gelatinous substance disappears, and leaves only the skeleton or sponge, 
formed by the combination of a multitude of small capillary tubes, capable 
of receiving water in the interior, and of becoming thereby distended. 
Though different in their nature, sponges are analogous in their formation 
to coral. On being examined with a power of about 500 linear, the fleshy 
matter of the living sponge is to be distinctly observed, liaving in its interior 
gemmae, which are considered to be the young. These are occasionally 
given off from the mass of living matter. The greater portion of the mass 
of sponge consists of small cylindrical threads or fibres, varying in size. 
The spiculse are not found within these, but in the large and flattened 
fibres, and varying in number from one to three or more, imbedded in their 
substance." From Brande's Dictionary. 
^» See B. iv. c. 17. 
