VARIABILITY IN LIGHT 137 



struck fire out of the black atmosphere ; as if the 

 winds were being set upon that planetary grindstone, 

 and gave out such momentary sparks from their 

 edges. Their silence is more striking than their 

 flashes, for sudden phenomena are almost invariably 

 attended with some noise, but these little jewels dart 

 along the dark as softly as butterflies. For their 

 light, it is not nearly so beautiful and poetical as 

 our still companion of the dew, the glow-worm, with 

 his drop of moonlight." 



I agree with Beddoes, but his pretty description of 

 our insect is not quite accurate, as I saw this evening, 

 when, after copious rain, the sky cleared and a full 

 moon shone on a wet, dusky-green earth. The light 

 of the suspended glow-worm was of an exquisite golden 

 green, and, side by side with it, the moonlight on 

 the wet surface of a polished leaf was shining silver- 

 white. 



The light varies greatly in power, according, I 

 suppose, to the degree of excitement of the insect 

 and to the atmospheric conditions. Occasionally you 

 will discover a light at a distance shining with a 

 strange glory, a light which might be mistaken for a 

 will-o'-the-wisp, and on a close view you will probably 

 find that a male is on the scene, and the female, aware 

 of his presence though he may be at some distance 

 from her, invisible in the darkness, has been wrought 

 up to the highest state of excitement. You will find 

 her clinging to a stem or leaf, her luminous part raised, 



