Ears 



45 



ridge. But the fibres from the cells of the upper 

 group of rods (supra-tympanal organ) pass into a special 

 supra-tympanal nerve (fig. 34 j-. /. n.) (23, a, 24). 



In Locusts and short-horned Grasshoppers a large 

 ear is situated on either side of the foremost seg- 

 ment of the hind-body. It consists of a tense, ovate 



sto.f 



B C 



Fig. 34. — Ear of long horned Grasshopper. A. Sketch of knee-joint showing 

 position of ear-slits (a. a) ;y^. thigh ; /j^. shin. ^. Cross section of shin. C 

 Longitudinal section ; a. outer openings ; /'. outer chambers ; ty. drum ; c. a. 

 ridge (crista acustica) ; tl\ n. tibial nerve ; ty. n. tympanal ner\-e ; st. n. 

 supra-tympanal nerve ; tr. air-tubes ; s. i. o. i, 2, upper and lower divisions 

 of supra tympanal organ; i. o. nerve-endings (intermediate organ). From 

 Carpenter (after Von Adelung), Natural Science, vol. 2. 



membrane or drum surrounded by a firm ring. On 

 the inner face of the drum are two horn-like processes 

 to which is attached a delicate bag full of clear fluid. 

 Connected with this are a number of rod-like nerve- 

 endings, whence fibres lead through a nerve-centre 



