16 Dr. & the Rev. S. Graham Brade-Birks— 



to traujrc the fall of iiitensitv more exaetlv. With furtlicr 

 rt'tinemciits niucii greater accuracy might be attained by 

 such a method. 



StinuUation. 



Ill the case of G. curpophayus we have found tliat tlie 

 following stimulations will cause the production of light : — 



(i.) HandliiKj. 



(ii.) Pressure. 



(iii.) Sudden immersion in water. 



(iv.) Electric current from an induction-coil. 



Most of these foregoing stimulations were seen iu deter- 

 mining other points. Probably special experiments would 

 reveal many other ways of stimulating the production of 

 light bv these animals. 



(v.) Exposure in a glass tube to cual-fjas passing through 

 the tube. 



In this case the centipede was only momentarily lumiuons. 



(vi.) Attack by ants. 



Here a centipede which did not appear to be luminous 

 when liandled liecame so when ants were place. I with it in 

 the same tube. 



(vii.) On meeting another individual. 



Two centi|>edes, neither of which exhiljited any luminosity 

 on handling separately, were jjlaccd one by one in the same 

 tube. Upon the introdni;tion of the latter sijecimen there 

 was a luminous display arising from one or both individuals. 



Reference has already been made in our thirteenth 

 pa|)er (2} to the methods of stimulating luminosity in Kent 

 centipedes by local workers. 



(viii.) liij crushing after death. 



It is convenient to add here that on one occasion when a 

 j)art of the body of an individual, recently killed, was 

 crushed in the dark phosphorescence was produced. The 

 centipede had been killed in alcohol and the alimcntaiy 

 canal had been removed subsequently before the experiment. 



