Ix INtRODUCTl0^f. 



The Nervous System. 



But little can be here said with reference to the 

 intricate network of nerves which can be traced in the 

 bodies of the Cicada. 



Concisely, it may be said that the cephalic ganglion 

 is bilobed, and that each lobe sends off one branch to 

 the eye, and another smaller branch to the ocellus. 

 Each antenna also is similarly furnished, though the 

 filament is minute. Posterior to the cephalic lobes a 

 nervous ring occurs, which surrounds the oesophagus. 

 Some anatomists refer this ring to the cerebellum. 



The great thoracic ganglion appears with a marked 

 constriction. The anterior portion throws off lateral 

 twigs to the legs, and to the alary organs ; whilst the 

 posterior ganglion distributes, through two large 

 trunks, the nerves which supply the viscera of the 

 abdomen and the apparatus of the reproductive 

 organs. 



The Reproductive System. 



The generative organs of the Tettigida; do not 

 greatly vary from those of the Aphididae ; yet certain 

 modifications are to be noted in their external parts. 

 As has been before stated, the external genitalia of 

 the males become much specialised in different 

 genera. Many examples of these peculiar forms are 

 figured in my plates. 



The internal parts may be said to consist essentially 

 of one pair of testes, each testis has its vesica seminalis 

 and deferent ducts, which finally open into an ejacu- 

 latory canal, bulbous at its root. The penis is of various 

 forms. In Lihiiniia it is sometimes long and straight, 

 except at the end, which is hooked and accompanied 

 by two fine bristles. In Idiocerus it occasionally takes 

 a plumose or feather-like form. It is probable that 

 this barbed construction may act as an irritating organ 



