108 ON THE LUMINOSITY 



a whole swarm of these insects, having taken possession of one 

 tree, and spread themselves over its branches, sometimes hide 

 their light all at once, and a moment after make it appear again 

 with the utmost regularity and exactness, as if they were in a 

 perpetual systole and diastole." This was on the river Meinam. 

 Of Buprestis vittata, in Japan, he says, " Another particular 

 sort of Spanish flies is called Fan-mio ; they are extremely 

 caustic, and ranked among the poisons. They are found upon 

 rice-ears, and are long, slender, and smaller than the Spanish 

 flies, blue, or gold coloured, with scarlet or crimson spots and 

 lines, which makes them look very beautiful." He thus de- 

 scribes another insect unknown to me : — " But the finest of all 

 the flying tribe of insects, and which, by reason of its incom- 

 parable beauty, is kept by the ladies among their curiosities, is 

 a peculiar and scarce night-fly, about a finger long, slender, 

 round-bodied, with four wings, two of which are transparent, 

 and hid under a pair of others, which are shining, as it were 

 polished, and most curiously adorned with blue and golden 

 lines and spots. They say that all other night-flies fall in love 

 with it; and that to get rid of their importunities, it maliciously 

 bids them (for a trial of their constancy) to go and to fetch fire. 

 The blind lovers scruple not to obey commands ; and flying to 

 the next fire or candle, they never fail to burn themselves to 

 death. The female is not near so beautiful as the male, but 

 grey, or ash-coloured, and spotted." Howison, in his " Views 

 of European Colonies," thus notices the West Indian fire- 

 flies : — " One species emits a flash of white light at regular 

 intervals of two or three seconds ; while the other, or larger 

 kind (Elater noct'ducus), displays two blazing spots of an 

 emerald colour, and of unremitting brightness. The aborigines 

 of Hispaniola are said to have employed the fire-flies of the 

 latter sort to destroy the gnats and small insects which infested 

 their huts, and also to give light in the evenings, and when 

 they went abroad. In the last case, they would tie several 

 fire-flies to their toes, and be guided by their light during a 

 journey through the darkest woods. In the present day, the 

 poorer inhabitants of Cuba often use as a lantern, a calabash 

 pierced with small holes, and containing twelve or fifteen 

 Cucuyos ; these afford sufficient light for all ordinary pur- 

 poses, but it is necessary to shake the vessel occasionally, in 

 order that the concussion may excite the insects to give out 



