326 



ZOOLOGY. 



sound, heard and appreciated by individuals of the other 

 sex. Any insect which produces a sound must be supposed to 



have ears to hear the sound pro- 

 duced by others of its species. 

 In the antennae, palpi, and 

 abdomiual appenda,ges of dif- 

 ferent insects are seated mi- 

 nute olfactory organs consisting 

 do^S^pV^-AS^o^a^fllfeC;^); of pits alone (Fig. 285), or of 

 ;afp'ro?%?<^°iS?h'o'r'r"' ^""""^ liairs perforated at the end, and 



pegs associated with the pits. 

 The ears (or auditory sacs) of the locust are situated, one 

 on each side, on the basal joint of the abdomen, just be- 



Pig. 286— Ear of a locust (CalopUnvg iiaHeus) «eeD from the inner eide. T, tym- 

 1 anom ; TS, its border ; o, a. two horn-like processes ; hi. iwar-sbaped vesicle ; n, 

 aaditory nerve ; ga, terminal ganglion; st. stigma ; m, opening and m' closing mns- 

 de of the same ; M, tem<or mnscleof the tympanum-membrane.— After Graber. 



hind the first abdominal spiracle (Fig. 274). The ap- 

 paratus consists of a tense membrane, the tiimpnnuin, sur- 

 rounded by ahomy ring (Fig 286). " On the internal sur- 



