4^0 THE DEATH-WATCH TERMED. 



numbers during the summer months ; but, when 

 disturbed, they run so nimbly into a hiding-place as 

 not often to be remarked. When they are dis- 

 turbed, they are very shy in making their noise, 

 but it they can be viewed without being alarmed 

 by noise, or moving the place where they are, they 

 will not only beat freely but even answer any per- 

 son's beating with his nail. At every stroke their 

 body shakes, or seems affected as by a sudden jerk -, 

 and these jerks succeed each other so quickly that 

 it requires great steadiness to perceive with the 

 naked eye that the body has any motion. They are 

 scarcely ever heard to beat before July, and never 

 later than the sixteenth of August. It appears 

 strange that so small an animal should be able to 

 make a noise so loud as is frequently to be heard 

 from this ; sometimes equal to that of the strongest 

 beating watch. Dr. Derham seems to have been 

 the first naturalist who examined and described this 

 species. He had often heard the noise, and in pur- 

 suing it had found nothing but these insects, which 

 he supposed incapable of producing it ; but one day, 

 by finding that the noise proceeded from a piece of 

 paper loosely folded, and lying in a good light in his 

 study window, he viewed it through, and with a 

 microscope observed, to his great astonishment, one 

 ot them in the very act of beating. In some years 

 they are more numerous than in others, and their 

 ticking is of course more frequently heard : Dr. 

 Derham says that, during the month of July, in one 

 particular summer, they scarcely ever ceased, either 

 in the day or night. 



