456 
PLINT's HISTOEY. 
[Book IX. 
which have been left adhering to the rock. They leave a 
colour similar to that of blood upon the rock from which they 
have been detached, and those more especially which are pro- 
duced in the Syrtes of Africa.^^ 
The manos is the one that grows to the largest size, but the 
softest of all are those found in the vicinity of Lycia. Where 
the sea is deep and calm, they are more particularly soft, while 
those which are found in the Hellespont are rough, and those in 
the vicinity of Malea coarse. "When lying in places exposed 
to the sun, they become putrid : hence it is that those which 
are found in deep water are the best. While they are alive, they 
are of the same blackish colour that they are when saturated 
with water. They adhere to the rock not by one part only, 
nor yet by the whole body : and within them there are a 
number of empty tubes, generally four or five in number, by 
means of which, it is thought, they take their food. There 
are other tubes also, but these are closed at the upper extremity ; 
and a sort of membrane is supposed to be spread beneath 
the roots by which they adhere. It is well known that 
sponges are very long-lived. The most inferior kind of all are 
those which are called aplysiae,"^^ because it is impossible to 
clean them : these have large tubes, while the other parts of 
them are thick and coarse. 
CHAP. 70. (46.) — noG-risH.*^ 
Vast numbers of dog-fish infest the seas in the vicinity of 
the sponges, to the great peril of those who dive for them. 
These persons say that a sort of dense cloud gradually thickens 
over their heads, bearing the resemblance of some kind of 
^9 This, to the end of the Chapter, is almost verbatim from Aristotle, Hist, 
Anim. B. iv. c. 17. 
60 See B. iv. cc. 8, 10. 
51 'ATrXvaiai, from a, " not," and ttXvvu)^ "to wash." These aplysiae 
or halcyones, Cuvier says, are a kind of sponge, of too thick and compact a 
nature to admit of their being washed. It is arbitrarily, he says, that 
Linnaeus has applied this name to a species of the moUuscae, which is, in 
reality, the sea-hare of the ancients. 
^'^ It is pretty clear that under the name of " canicula," dog-fish," or 
canis marinus," " sea-dog," Pliny includes the whole genus of sharks. 
^3 Eondelet and Dalechamps absolutely interpret this passage as though 
it were the dog-fish and fiat-fish over whose eyes this cloud comes, and 
the latter proceeds to describe it as a malady which hinders the fish from 
taking its own part in the combat. Hardouin, however, detects this 
