MECHANORECEPTION 



39 



700- 



500 



400 



c 

 o 



a. 



C 300 

 U; 200 



100 



\«. • " • ' 



♦ -•— • • — « . 



5 6 



Seconds 

 A 



B 



Fig. 29. A. Adaptation of a nerve-ending in the inner coxal hair plate of 

 Periplaneta to a stimulus of a constant deflexion of the hairs. Two 

 records from the same preparation. B. Diagram to illustrate the 

 method of excitation of the inner coxal hair plate by a fold of the inter- 

 segmental membrane. C, coxa; H, hair plate; P, pleuron. (Redrawn 

 from Pringle, 1938c.) 



fixation-line) and the proprioceptive-centre message (a function of 

 the angle of the head with respect to the body axis). If fixation move- 

 ments have come to rest the direction of stroke is determined by the 

 optic and, to a lesser extent, by the proprioceptive-centre messages, 

 which then both contain the required information (Mittelstaedt, 

 1957). 



D 



