THE BEETLE. 393 



spoils of which are converted to such useful purposes. The 

 gall-insects are bred in a sort of bodies adhering to a kind of 

 oak in Asia, which differ with regard to their colour, size, 

 roughness, smoothness, and shape, and which we call galls. 

 They are not fruit, as some have imagined, but preternatural 

 tumours, owing to the wounds given to the buds, leaves, and 

 twigs of the tree, by a kind of insects that lay their eggs within 

 them. This animal is furnished with an implement, by which 

 the female penetrates into the bark of the tree, or into that spot 

 which just begins to bud, and there sheds a drop of corrosive 

 fluid into the cavity. Having thus formed a receptacle for her 

 eggs, she deposits them in the place, and dies soon after. The 

 heart of the bud being thus wounded, the circulation of the nu- 

 tritive juice is interrupted, and the fermentation thereof, with 

 the poison injected by the fly, burns the parts adjacent, and then 

 alters the natural colour of the plant. The juice or sap, turned 

 back from its natural course, extravasates, and flows round the 

 egg. After which it swells and dilates by the assistance of 

 some bubbles of air, which get admission through the pores of 

 the bark, and \Ahich run in the vessels with the sap. The ex- 



This insect is usually found in old wood, decayed furniture, museums, 

 and neglected books ; and both the male and female ha\e the power of mak. 

 lUg a ticking noise, not unlike that of a watch, to attract each other. The 

 female lays her eggs in dry and dusty places, where they are likely to meet 

 with the least disturbance : these are exceedingly small, and are not unlike 

 the nits or eggs of lice. WHien they are disturbed, they are very shy in 

 making their tickings ; but if 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 person'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 .\ugust. It appears 

 strange that so small an insect should be able to make a noise so loud as is 

 frequently to be heard from tiiis; sometimes equal to that of the strongest 

 beating watch. Dr Derham, who examined and first described this species, 

 says, he had often heard the noise, and in pursuing it 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 astonislunent, one of them in the very act 

 of beating. In some years they are more nimierous than in others, and their 

 ticking is of course more frequently heard. We are informed by the above 

 naturalist, that, during the month of July, in one particular summer, they 

 Bcarcely ever ceased, either in the dav or night, 

 TV. :ih 



