102 THE GLOW-WOKM 



the two bands of white material on her abdomen, and 

 can extinguish the light altogether by closing the tube. 

 These bands are absent in the male; but both sexes 

 carry a small lantern on the last segment of the 

 abdomen the tail, as it would be termed in popular 

 parlance which diffuses a modest glow, not only in the 

 adult insect, but also in the larva. Even the eggs are 

 more or less luminous. 



It is at this point that Professor Harvey steps in, and, 

 after recapitulating the successive stages of research in 

 this matter, carries it a stage further towards elucidation. 



Fabre's contribution to the life-history of the glow- 

 worm was not limited to analysis of its luminescence. 

 He ascertained what was its food ; and if he was not 

 the first observer to settle that question, none preceded 

 him in detecting the mode which this voracious little 

 beetle adopts in taking its prey. It feeds exclusively 

 on the flesh of snails, and has to watch vigilantly for a 

 chance of getting access to the snail's mantle. Let but 

 a fragment of the fringe of that mantle show from 

 beneath the shell, and the glow-worm seizes the 

 opportunity. A single nip with its hooked mandibles 

 sufficeth to paralyse the snail, for the glow-worm 

 injects a fluid which deprives the mollusc of all control 

 of its muscles and, let us hope, of all feeling, for the 

 captor immediately sets to work sucking the juices of 

 its victim, and leaves it not until the skin is empty. 

 Anaesthesia, the hinge whereon the most delicate 

 operations in modern surgery revolves l the crowning 



1 More correctly, one of the hinges, others being antiseptic treat- 

 ment and X-rays. 



