FIREFLIES AND GLOW-WORAI"^ AND THETR LIGHT. 191 



If the female beetle has been secured, she should be kept alive 

 and placed in a likely situation, and a watch kept for the males 

 coming to visit her. At the same time it is essential that careful 

 notes should be made of the behaviour of the female and of the arrival 

 of the male. As an indication of what maj^ be expected a brief ac- 

 count of the habits of some of our better known species may not be 

 out of place. 



Many members of the Natural History Society of Siam will no 

 doubt be familiar with the common Glow-worm of our English lanes 

 and hedges. The pale greenish lights ma}' sometimes be observed in 

 numbers in the grass by the roadside in June and Jul3^ At Lugano 

 this summer they were noticed to be particularly partial to the walls, 

 sitting sometimes 10 or 12 feet from the ground, and in this situation 

 their light would be visible from a long distance. If more closely 

 observed, whether sitting on the ground amongst low vegetation, or 

 hanging vertically on some stem a few inches above it, the light will 

 be seen streaming from the organ on the underside of the tail ; the 

 bod}' is twisted first to one side then to the other, in order to expose 

 the light more fully. Often I have carefully noted the position of one 

 of these lights and visited the spot from time to time ; at one visit the 

 light has been found to have disappeared, but a careful search of the 

 spot where it should be, has revealed the female beetle with one or 

 more males in close attend mce. Unfortunately I have never been 

 able to witness the actual arrival of the male, which in this species is 

 not or but very feebly luminous. 



Mr. E. Gr. Green (M has published notes on the use of the light 

 of two species of Glow-worm from Ceylon, in one of these, Lampro- 

 phorm tenehrosiis, the apterous female exhibits her light much as does 

 our Glow-worm ; the male, though normally brilliant, approaches a 

 "calling" female with the light shut off, its advent being heralded 

 only by the partial extinction of the light of the female. In the 

 other, Dioptoma aclamsi, the larviform female was observed to recurve 

 the body over the back so as to exhibit the ventral subterminal light 

 organ. On the approach of the male, the light was partially eclipsed 

 and the tail turned down. The male at the time was not known to be 

 luminous, but under the stimulus of sexual excitement it was ob- 

 served to exhibit luminous spots along the sides of the abdomen 



( 1 ) 7V,7».s\ Kr}t. Sor. 1012. p. 717. 



