THE CLICK BEETLES. 113 



by a small cavity in the front of the mesothorax or 

 second thoracic segment. 



Whenever we meet with an example of this group, 

 we shall soon see the use of this singular arrangement. 

 Almost everywhere, and at almost all seasons of the 

 year, we may find both in fields and gardens some 

 beetles of the form above described, measuring about 

 a third of an inch in length, of a blackish or dusky 

 grey tint, and clothed with short hairs (Agriotes 

 obscurus or lineatus). If one of these little beetles be 

 taken into the hand, he immediately draws up his legs 

 close to his body, turns his antennae back under his 

 thorax, where they are concealed in small grooves, 

 and to the best of his power counterfeits death. But 

 if we turn him on his back to see what has become of 

 his limbs, he will be seen suddenly to execute what 

 looks like a convulsive movement, raising the middle 

 of his body until he rests upon his head and tail, and 

 then suddenly, with a little click, he vanishes from 

 the hand of his captor. For the power of performing 

 this curious and seemingly inexplicable trick, he is 

 indebted to the peculiar structure of the thorax above 

 described. As the bending of the body takes place 

 at the junction of the two first segments of the thorax, 

 the little spine of the prothorax is of course drawn 

 completely out of the small cavity in which it was 

 reposing; the body is then suddenly straightened, 

 until its further progress is stopped by the entrance 

 of the spine into its socket, and this check is sufficient 

 to throw the insect into the air to a height of two or 

 three inches. The observation of this curious power 

 of springing from apparently the most helpless posi- 

 tion in which they could be placed, has obtained for 

 these beetles the expressive English name of Skip- 



