50 HOUSE, GARDEN, AND FIELD 



tection does not account for a light which is visible from 

 afar, a light so intense as to arouse the curiosity of danger- 

 ous enemies. Belt's explanation is not, properly speaking, 

 an alternative to the attraction-theory. Both may be 

 held together, if both should be adequately supported by 

 facts. The light of the glowworm may guide the male to 

 the resting-place of his mate, and also prevent insectivorous 

 birds, drawn to the spot by the unusual glow, from de- 

 vouring her by mistake. 



Others have imagined that the light attracts the prey 

 of the glowworm, just as a luminous fish, or an electric 

 lamp lowered into the sea attracts crowds of small Crustacea 

 and other animals. There is, I believe, no proof that the 

 mollusks, on which the glowworm is believed to feed, are 

 sufficiently curious to draw near to a light, nor that the 

 glowworm can fascinate more susceptible victims. 



Until further enlightened, therefore, I shall continue to 

 hold with Gilbert White that the light of our English 

 glowworm is the lamp of Hero. 



Glowworms are most abundant in the neighbourhood of 

 woods. Bongardt tells us that after mating the females 

 creep into the woods, at the rate of about a yard a day. 

 At this time they are hard to find, for the luminous 

 surface is turned towards the ground. It is only when 

 expecting the visit of the male that the glowworm fully 

 exposes her light-organs, either by climbing on a stalk, or 

 by turning up the end of the abdomen. 



XII. INVISIBLE DOMESTIC SERVANTS. 



When we have counted up all the men and women, 

 quadrupeds, birds, insects, spiders and mites that can be 

 found under our roofs, besides the green plants that are 

 grown in the windows, we have not come to the end of 

 the living things of the house. There are still the micro- 

 scopic organisms to be considered, and these are both 



