THE ANIMAL KINGDOM. Ill 



seem to hear sounds which are serviceable to them, whilst 

 others, whatever be their intensity, do not affect them in 

 any way. The queen-bee, by means of a scarcely per- 

 ceptible hum, sets all her people in movement, and com- 

 pels an army of combatants to follow her ; but if, on the 

 contrary, fire-arms be discharged quite close to a colony of 

 bees, not one of them stirs; it seems as if the sound was not 

 noticed by them. 



54. Diversiform Antennae. 



The horse has only one stomach, the insect has often 

 three : in the former it occupies only a somewhat limited 

 portion of the body; in the other it sometimes forms almost 

 the entire body, the animal resembling a walking digestive 

 sack. The ravenous activity of many Orthoptera (locusts, 

 etc.) is even aided by great teeth, placed in the interior of 

 the stomach, which act like a second mouth, and complete 

 the crushing of anything that has escaped the action of the 

 jaws. 



In certain caterpillars the digestive power is so great that 

 they swallow every day three or four times their own 

 weight of food. If the elephant and rhinoceros were to 

 feed on this scale, and were as numerous as the others, 



