Chap. 67.] SENSITIVENESS OF WATER ANIMALS, 451 



without a companion, which some writers call the pinnotheres, 20 

 and others, again, pinnophylax, being a small kind of shrimp, 

 or else a parasitical crab. The pinna, 21 which is destitute of 

 sight, opens its shell, and in so doing exposes its body within 

 to the attacks of the small fish, which immediately rush upon it, 

 and finding that they can do so with impunity, become bolder 

 and bolder, till at last they quite fill the shell. The pinno- 

 theres, looking out for the opportunity, gives notice to the 

 pinna at the critical moment by a gentle bite, upon which 

 the other instantly closes its shell, and so kills whatever it has 

 caught there ; after which, it divides the spoil with its com- 

 panion. 



CHAP. 67. THE SENSITIVENESS OF WATEB ANIMALS J THE TORPEDO, 



THE PASTINACA, THE SCOLOPENDEA, THE GLANIS, AND THE 

 EAM-FISH. 



Upon 22 reflecting on such facts as these, I am the more in- 

 clined to wonder at the circumstance that some persons have 

 been found who were of opinion that the water animals are 

 devoid of all sense. The torpedo 23 is very well aware of the 

 extent of its own powers, and that, too, although it experiences 

 no benumbing effects from them itself. Lying concealed in 



20 We have already had an account of one pinnotheres, in c. 51. Some 

 of the editions, however, make a difference in the spelling of the name, 

 and call the animal mentioned in the 51st Chapter, " pinnotheres," and 

 the one here spoken of, the " pinnoteres," the "guardian of the pinna;" 

 from the Greek verb r^/oio>, "to keep," or "guard." "Pinnophylax" 

 has the same meaning. 



21 Cuvier says, that in the shell of the pinna, as, in fact, of all the bi- 

 valves, there are often found little crabs, which are, as it were, imprisoned 

 there ; and that it is this fact that has given rise to the story of the treaty 

 of amity between these two animals, which appears in various authors, and 

 is related in various forms, which only agree in being devoid of truth. Cu- 

 vier says that a careful distinction must be made between the pinnotheres 

 of this Chapter, the one of which Aristotle makes mention, and that which 

 is mentioned by Pliny in c. 51, the hermit-crab of the moderns. There 

 can, however, be but little doubt that they are different accounts of the 

 same animal. 



22 The whole, nearly, of this Chapter is taken from Aristotle, B. v. c. 16. 



23 Plutarch speaks of this fish, in his " Treatise on the Instincts of Ani- 

 mals ;" also Oppian, Halieut. B. ii. 1. 62. The Raia torpedo of Linnaeus, 

 Cuvier says, has on each side of the body a galvanic organ, which produces 

 an electric shock, similar to that communicated by the use of the Leyden 

 vial. By this means it baffles its enemies, and drives them away ; or else, 

 having stupefied them, devours them at its leisure. 



G G 2 



