insects: their mouths. 165 



slender cylindrical tube, formed of a multitude of close- 

 set rings, and covered with fine hairs. Some deny it to 

 be tubular, and maintain that it is solid ; but certainly 

 it appears to me to have a distinct cavity throughout, 

 with thickish walls. 



Under a high power the structure of the investing 

 hairs is very interesting ; for they are seen to be flat 

 filaments of the yellow chitine, very much dilated at 

 their bases, and set side by side in regular whorls, the 

 bottom edges of which form the rings of which the 

 tongue is composed. The tip is probably a sensitive 

 organ of taste, for it terminates in a minute globose 

 pulpy body, whose surface is beset with tiny curved 

 points. Thus I have pointed out to you all the parts 

 which enter into the mouth of the beetle, except the 

 maxillary palpi ; and those, very small indeed, but 

 quite distinct, you may see, on the outer edge of the 

 maxillw, just below the point where their outline begins 

 to swell into its graceful curve. 



The cylindrical tongue is capable of considerable 

 extension and contraction at the will of the animal, 

 being sometimes pushed far out of the mouth, and at 

 others quite concealed within its sheath. " The man- 

 ner," observes Mr. Newport, " in which the honey is 

 obtained, when the organ is plunged into it at the bot- 

 tom of a flower, is by lapping, or a constant succession 

 of short and quick extensions and contractions of the 

 organ, which occasion the fluid to accumulate upon it, 

 and to ascend along its upper surface, until it reaches 

 the orifice of the tube formed by the approximation of 

 the maxillcB above, and of the labial palpi, and this 

 part of the ligula below." 



Well might Swammerdam, when describing this 



