SEAT OF THE SENSE OF HEARING. 97 



how immovably outward it spread its antennte, and 

 holds them porrect, as it were with great attention, as 

 long as it listens, and how carefully the insect proceeds 

 in its course when it conceives that no clanger threatens 

 it from the unusual noise." * 



Other similar observations might be quoted, but 

 these sufficiently indicate that in some insects, at any 

 rate, the organs of hearing are situated in the antennse. 



On the other hand, Lehmann long ago observed 

 that the house cricket (Achefa domestica), when 

 deprived of its antennae, remained as sensitive to 

 sounds as previously. This is quite correct ; and yet, if 

 a cricket be decapitated, and a shrill noise be made 

 near the head, the antennae are thrown into vibration 

 by each sound. 



In fact, not only do the highest authorities differ, 

 but the observations themselves appear at first sight 

 to be contradictory. The explanation seems to be that 

 the sense of hearing is not confined to one spot. That 

 the antennae do serve as ears, at least in some insects, 

 the evidence leaves, I think, no room for doubt. But 

 there is no reason, in the nature of things, why the 

 sense of hearing should be confined to one part of the 

 body. Taste, indeed, would be useless except in or 

 near the mouth, and almost the same may be said of 

 smell. But the sense of touch is spread, in greater or 

 less perfection, over the whole skin. Indeed, there is 

 among the lower animals a great tendency to repeti- 

 tion, and not least so amongst insects. The body con- 

 sists normally of a number of segments, each with a 

 pair of appendages and a ganglion. There are three 

 pairs of legs ; two pairs of jaws, opening, not vertically, 



* Transactions of the Linnean Society, vol. xxii. 



H 



