456 plii^t's natural history. [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 Ipng 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 " aplysise,"^^ because it is impossible to 

 clean them : these have large tubes, while the other parts of 

 them are thick and coarse. 



CHAP. 70. (46.) DOG-FISH.'- 



Yast 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 



49 This, to the end of the Chapter, is almost verbatim from Aristotle, Hist. 

 Anim. B. iv. c. 17. 



50 See B. iv. cc. 8, 10. 



51 'A7r\ycria/., 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 molluscae, which is, iu 

 reality, the sea-hare of the ancients. 



52 It is pretty clear that under the name of " canicula," " dog-fish," or 

 " canis marinus," "sea-dog," Pliny includes the whole genus of sharks. 



^' Rondelet and Dalecharaps absolutely interpret this passage as though 

 it were the dog-fish and flat-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 



