Chap. 112.] DIFFERENT VOICES OF ANIMALS. 93 



with the exception of man and the ape, have tails in propor- 

 tion to the necessities of the body. In animals with bristles 

 the tail is bare, as in the boar, for instance. In those that are 

 shaggy, it is small, such as the bear ; while in those animals 

 that have long hair, the tail is long also, the horse, for in- 

 stance. The tail of a lizard or serpent, if cut off, will grow 

 again. The tail governs the movements of the fish like a 

 rudder, and turning from side to side, to the right or to the 

 left, impels it onwards, acting in some degree like an oar. 

 A double tail is sometimes found in lizards. In oxen, the 

 stalk of the tail is of remarkable length, and is covered with 

 rough hair at the extremity. In the ass, too, it is longer than 

 in the horse, but in beasts of burden it is covered with bristly 

 hairs. The tail of the lion, at the extremity, is like that of 

 the ox and the field-mouse ; but this is not the case with the 

 panther. In the fox and the wolf it is covered with long 

 hair, as in sheep, in which it is longer also. In swine, the 

 tail is curled ; among dogs, those that are mongrels carry it 

 close beneath the belly. 



CHAP. 112. (51.) THE DIFFERENT VOICES OF ANIMALS. 



Aristotle 52 is of opinion that no animal has a voice which 

 does not respire, and that hence it is that there is no voice in 

 insects, but only a noise, through the circulation of the air in 

 the interior, and its resounding, by reason of its compression. 

 Some insects, again, he says, emit a sort of humming noise, 

 such as the bee, for instance ; others a shrill, long-drawn note, 

 like the grasshopper, the two cavities beneath the thorax re- 

 ceiving the air, which, meeting a moveable membrane within, 

 emits a sound by the attrition. — Also that flies, bees, and 

 other insects of that nature, are only heard while they are 

 flying, and cease to be heard the moment they settle, and that 

 the sound which they emit proceeds from the friction and the 

 air within them, and not from any act of respiration. At all 

 events, it is generally believed that the locust emits a sound 

 by rubbing together the wings and thighs, and that among 

 the aquatic animals the scallop makes a certain noise as it 

 flies. 53 Mollusks, however, and the testaceous animals have no 

 voice and emit no sounds. As for the other fishes, although 



52 Hist. Anim. B. iv. c. 9. 53 See B. ix. c. 52. 



