454 PLINY'S NATURAL HISTOET. [Book IX, 



itching, smarting pain, 37 just like that caused by the nettle found 

 on land. For the purpose of seeking its prey, it contracts and 

 stiffens itself to the utmost possible extent, and then, as a 

 small fish swims past, it will suddenly spread out its branches, 

 and so seize and devour 38 it. At another time it will assume 

 the appearance of being quite withered away, and let itself be 

 tossed 39 to and fro by the waves like a piece of sea- weed, until 

 it happens to touch a fish. The moment it does so, the fish 

 goes to rub itself against a rock, to get rid of the itching ; im- 

 mediately upon which, the nettle pounces upon it. By night 

 also it is on the look-out for scallops and sea-urchins. When 

 it perceives a hand approaching it, it instantly changes its 

 colour, and contracts itself; when touched it produces a 

 burning sensation, and if ever so short a time is afforded, 

 makes its escape. Its mouth is situate, it is said, at the root or 

 lower part, 40 and the excrements 41 are discharged by a small 

 canal situated above. 



CHAP. 69. SPONGES ; THE VARIOUS KINDS OF THEM, AND WHERE 



THEY ARE PRODUCED : PROOFS THAT THEY ARE GIFTED WITH 

 LIFE BY NATURE. 



We find three ** kinds of sponges mentioned ; the first are 



37 Many species of the medusae, Cuvier says, and other animals of the 

 same class, the physalus more especially, cause an itching sensation in the 

 skin when they are touched. This is noticed also by ^Elian, Hist. Anim. 

 B. vii. c. 35 ; and by Diphilus of Siphnos, in Afhenaeus, B. iii. 



38 This is true, Cuvier says, and more especially with reference to the 

 actiniae. They have the mouth provided with numerous fleshy tentacles, 

 by means of which they can seize very small animals which come within 

 their reach, which they instantly swallow. 



39 Cuvier says, that this is the case more especially with the medusae 

 and the physali. 



40 " Ora ei in radice." Aristotle, however, says, Hist. Anim. B. iv. c. 5, 

 and B. viii. c. 3, that the sea-nettle has the mouth situate sv JW(T<^, "in the 

 middle of the body." Hardouin attempts to explain the passage on the 

 ground that Pliny has made a mistake, in an endeavour to suit his similitude 

 of a tree to the language of Aristotle. Cuvier says, that there exists one 

 genus or species of the medusae, which appears to feed itself by the aid of 

 an apparatus of branches, and is divided into such a multitude of filaments, 

 almost innumerable, that it bears a strong resemblance to the roots of a 

 tree or vegetable. It is this kind, he says, that he has called by the name 

 of " Rhizostomos." 



41 Aristotle, Hist. Anim. B. viii. c. 3, says the same ; though, on the 

 other hand, in the Fourth Book, he says that the animal has no excrements, 

 although it has a mouth, and feeds. 



48 Cuvier remarks, that there are a great many more than three kinds 



