216 



NATURAL HISTORY. 



case when one lifts the stone under which it is concealed, it shoots off a 

 portion of this liquid with a slight popping noise, and the liquid, as it 

 turns to vapor, produces the effect of smoke, thus making the comparison 

 to a cannon almost complete. The novice at collecting is pretty apt to 

 drop his first specimen when it shoots off its gun in his face. 



Another genus which occurs in Mammoth Cave is remarkable from the 

 fact that it has no eyes, either in the larval or adult stages, a fact indicated 

 in the scientific name — Anophthalmus — which is applied to it. Its 

 nearest relatives are well provided in this respect. Concerning the other 

 species of the group there is but little of general interest to relate, as all 

 arc greatly similar in their habits. 



The tiger-beetles, the last group of the Coleoptera, are even more pre- 

 daceous than the carabids, and it is to their carnivorous habits that they 

 owe their common name. Many of them are brightly colored, the metallic 

 green wings of some of our most abundant species being common objects 

 on the sunny paths in summer. As one walks along, they rise and fly a 

 few feet to settle down until alarmed again. Other species occur on the 

 sea-shore, and these have their bodies of a color which harmo- 

 nizes well with the surroundings, and is evidently protective in 

 its nature. The larvae of the tiger-beetles are as 

 predaceous as the adults ; they live in burrows in 

 the earth and climb up and down by means of two 

 large hooks upon the back of the abdomen. They 

 lay in wait at the mouth of their burrows, with only 

 the head and large jaws exposed, and when a fly or 

 fig. 214.— Tiger-beeties (dan- ant comes near them, it is quickly seized and taken 



to the bottom of the hole, where it is devoured. The 

 ]Hrfect beetles are very handsome, but these larvae are hideous, misshapen 

 monsters, the hooks on the back, their round shoulders, and their ugly faces 

 making one think of such characters as Quilp. 



Ants, Wasps, and Bees. 



In scientific works the ants, wasps, bees, and their numerous allies fig- 

 ure under the name Hymenoptera, a term which alludes to the membranous 

 • liaracter of the wings, the second pair of which are always smaller than 

 ilic first. It is to be noticed, however, that there are individuals which 

 never acquire wings. This is true of the neuters, or workers among the 

 ants, while in other forms one sex may be winged, while the other lacks 

 organs of flight. In all the insects noticed in the preceding pages the 

 mouth parts are adapted for biting alone ; but in the present group they 



