BEHAVIOR OF FIRE FLIES 271' 



males fly about and glow fairly regularly at intervals of about 

 five seconds. The females do not glow unless light from the 

 males or from some other source is flashed on them. 



2. Immediately before a female glows in response to a male 

 she raises and twists the abdomen, until the luminous area on the 

 ventral surface is directed toward him, no matter where he is 

 located, then he ordinarily turns directly toward her and proceeds. 

 These reactions are repeated until the two 'come together, after 

 which copulation takes place at once. There is no other factor 

 involved in mating. If a female is held near a male he pays 

 no attention to her unless there is actual contact, showing that 

 neither vision nor smell is functional in mating. 



3. The males very rarely respond to the glow of other males 

 or to flashes of artificial light. In some way they are able to 

 distinguish between the illumination produced by the two sexes. 

 Although no marked difference, either in quality or quantity, 

 between the male and the female glow, was detected, experi- 

 mental results indicate that there is probably a slight difference 

 in duration and that this is the factor primarily involved in the 

 phenomenon in question. 



4. The males do not orient when exposed to continuous 

 illumination. They respond only to flashes of light and the 

 reaction does not begin until after the light has disappeared. 

 Removal of the female immediately after she glows has no effect 

 on this reaction. Thus orientation may take place in total 

 darkness, and it is surprising how accurately these animals 

 turn through the proper angle in the total absence of the stim- 

 ulating agent that caused the response. Here we have a case 

 in which it is clearly demonstrated that light does not act con- 

 tinuously in the process of orientation as demanded by Loeb's 

 theories, a case in which it is also clearly demonstrated that 

 continuous action of the stimulating agent is not necessary to 

 keep the organisms oriented. 



4 

 LITERATURE 



Dubois, R. Les Elaterides Lumineux. Bull. dc. la soc zool. de France, p. 1 



1886. 



Galloway, T. W. A Case of Phosphoresence as a Mating Adaptation. Sch. 



1908. Set. and Math., May. 



Galloway, T. W. and Welch, P. S. Studies on a Phosphorescent Bermuden 



1911. Annelid, Odontosvllis Enopla Verril. Trans, of the Am. Micr. Soc., 

 Vol. 30, pp. 13-39. 



