252 



FLASHLIGHTS ON NATURE 



Fig. A, vibrate sympathetically in unison with the 

 notes of a tuning-fork, within the range of the 

 sounds emitted by the female. In other words, 

 hairs and drums just answer to one another. We 

 may, therefore, reasonably conclude that the female 

 sings in order to please and attract her wandering 

 mate, and that the antennae of the male are organs 

 of hearing which catch and respond to the buzzing 

 music she pours forth for her lover's ears. A whole 

 swarm of gnats can be brought down, indeed, by 



uttering the appro- 

 priate note of the 

 race ; you can call 

 them somewhat as 

 you can call male 

 glow-worms by 

 showing a light 

 which they mistake 

 for the female. 



A much larger 

 and more powerful 

 British bloodsucker 



than the mosquito, again, is the gadfly or horse- 

 fly, whose life-size portrait Mr. Knock has drawn 

 for us in No. 10. Most people know this fear- 

 some beast well in the fields in summer. He 

 has a trick of settling on the back of one's neck, 

 and making a hole in one's skin with his sharp 

 mandibles ; after which he quietly sucks one's blood 

 almost without one's perceiving him. Horses in 

 pastures are often terribly troubled by these per- 

 sistent creatures, which make no noise, but creep 



NO. 10. THE GADFLY, NATURAL SIZE. 



