156 THE ENTOMOLOGIST. 



which may, perhaps, be best described as one of attention (see 

 Fig. 1). It rests with the body inclining downwards behind, 

 so that the end of the abdomen is very little raised above the 

 surface, and the insect looks as if squatting on the hind legs, 

 and raised on the middle legs, which are spread apart more 

 widely than the other legs, and have their tarsi resting firmly 

 on the plane of position. When the beetle taps, its whole body 

 is jerked forwards and backwards rapidly, and seems to swing 

 like a battering-ram, balanced on the middle legs and propelled 

 by the muscular force derived from the hind legs. The head 

 and prothorax, instead of being thrust forwards, are at this time 

 pressed back as far as they will go (see Fig. 2), and the head, at 

 each forward stroke, hits the object, sometimes with the front 

 of the mandibles, sometimes higher up, with the forehead, and 

 sometimes the strokes begin in the one way and end up in the 

 other. The front legs are somewhat shorter than the middle 

 legs, and their tarsi, less firmly planted, slide backwards and 

 forwards with the movement of the body. The number of taps 



Fig. 2. 



given in succession was generally eight, and the time taken 

 rather less than a second, but on cold mornings, when tapping 

 less vigorously than usual, the beetle would sometimes give only 

 five or six taps and at an appreciably slower rate, and on one 

 such occasion it gave twelve taps in succession, the time occupied 

 being fully two seconds. This beetle, which, as I discovered 

 later, was a female, very rarely tapped of its own accord. I 

 noticed it do so only on one or two occasions. But it was always 

 very ready to respond when anyone tapped with a pencil on the 

 table or on any other object near it, so long as the tapping was 

 done at the proper rate. 



No one seeing its ready response could for a moment doubt 

 that the beetle possessed the sense of hearing, or, if not exactly 

 hearing, a sense so extremely like it as hardly to admit of dis- 

 tinction. But it seemed to be a rather crude sort of sense, 

 incapable of detecting any difference in the sound or its source, 

 provided there was a quick enough succession of sounds follow- 

 ing in definite order like the beetle's own. The tapping to which 

 it would reply might be made on wood, on stone, on glass, on 

 metal, or any other substance. And when a rapid clicking was 

 made with one's tongue in the mouth, the response was just as 



