56 LIVING LIGHTS. 



the minute air-tubes. Regarding Luciola Italica, Professor 

 Emery says that the male Luciolce gave out light in two 

 distinct modes: in the night, when they are brisk and fly 

 about, the light increases and decreases at short, regular 

 intervals, so that it seems to twinkle. If one of them is 

 caught flying, or disturbed in its rest by day, it shines less 

 than at the maximum of its intensity when on the wing, 

 but without intermission. It is remarked, however, that the 

 luminous plates do not shine uniformly over their whole 

 extent ; but that sometimes one spot, and sometimes another, 

 glows more strongly. If such a specimen is examined under 

 the microscope, we perceive, on a dark background, bright, 

 luminous rings, which are not, however, uniformly brilliant, 

 but display certain more intense points, which flash up, and 

 again disappear, or continue to shine on faintly for a time, 

 re-appearing afterward in full splendor. These changes take 

 place without any regular succession. 38 



The common lightning-bugs of Europe are Lampyris nocti- 

 luca (Plate IX., Fig. <2) and L. splendidula (Fig. a). Their 

 life history is an interesting study,, and a brief description 

 will apply to all. In early spring we find the little yellow 

 eggs, perhaps gleaming with the wonderful phosphorescence, 

 and thus finding protection, attached to blades of grass or 

 other objects just above ground. The larva (Plate IX., 

 Fig. c), a long, narrow, flat creature, soon appears and begins 

 a predatory life ; even being provided with an apparatus for 

 removing the mucus of its victim. About the month of 

 April it attains its full vigor, and during the summer 

 changes to the pupa form, or hibernates all winter, entering 

 a deep sleep, and assuming its new shape the following spring. 

 We see the light from the very first in the eggs of some ; 



