MECHANORECEPTION 57 



can attempt to move to a more favourable environment before acute 

 respiratory distress ensues. 



It has been suggested that other chordotonal sensilla in the abdomen 

 of insects may act as rhythmometers in respiration (Eggers, 1928; 



Fig. 48. Diagrammatic repre- 

 sentation of a chordo- 

 tonal sensillum. C, cap 

 cell; E, enveloping cell; 

 S, sense cell; Sb, scolo- 

 poid body; D, dendrite; 

 A, axon. (Redrawn from 

 Schwabe, 1906.) 



Hughes, 1952). In Dytiscus and Locusta comphcated sensory activity 

 has been recorded in afferent segmental nerves of the abdomen 

 (Hughes, 1952). Three patterns of impulses have been recorded, indi- 

 cating that there are some end-organs that discharge during inspira- 

 tion, others that discharge during expiration, and some whose 



