SOUND RECEPTION 85 



locust Locusta migratoria migratorioides have been examined with the 

 electron-microscope. The relations between the various cells compos- 

 ing the unit are clearly revealed (Fig. 60). The axon and cell body of 

 the neuron are enveloped in a Schwann cell. Each Schwann cell may 

 envelope several neurons. Distal to the Schwann cell, at the base of the 



Fig. 60. A diagrammatic section through the sensory region of the locust 

 tympanic organ to show the method of attachment of the sensory cells. 

 H, hypodermis; E, elevated process; C, cap cell; Ci, cilium-like pro- 

 cess; S, scolopoid body; Sc, scolopale cell; D, dendrite; Sw, Schwann 

 cell; A, axon; F, fibrous sheath cell. (Redrawn from Gray, 1960.) 



dendrite, lies another enveloping cell, the fibious sheath cells (prob- 

 ably the Bindesubstanz of Schwabe). The remaining portion of the 

 dendrite is enclosed in the enveloping cell (Hiillzelle of Schwabe, 

 scolopale cells of Gray). Between this cell and the hypodermis lies the 

 cap cell (Kappenzelle of Schwabe, Deckzelle of Eggers, attachment 



