Chap. 67.] 
SEKSITIYEKESS 01" WATER ANIMALS. 
451 
without a companion, which some writers call the pinnotheres,'-^^ 
and others, again, pinnophylax, being a small kind of shrimp, 
or else a parasitical crab. The pinna, 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 WATEE ANIMALS ; THE TORPEDO, 
THE PASTINACA, THE SCOLOPENDEA, THE GLANIS, ANI) THE 
EAM-EISH. 
Upon 2^ 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 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 speUing 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?;p£w, 'Ho keep/' or "guard." "Pinnophylax" 
has the same meaning. 
2^ 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 Eaia torpedo of Linnaeus, 
Cuvier says, has on each side of the body a galvanic organ, whidi produces 
an electric shock, similar to that communicated by the use of the Ley den 
vial. By this means it baffles its enemies, and drives them away ; or else, 
having stupefied them, devours them at its leisure. 
a G 2 
