248 POPULAR SCIENCE MONTHLY. 



i&T as its depredations have been observed it confines its work to 

 the bindings of books, making furrows in all directions much as it 

 does in the sap wood of dead trees. The strong resemblance of its 

 burrowing to the gouging done by an engraver's chisel has given to 

 this family the name of " engraver beetles." 



A review of the different families of insects whose habits under 

 favorable conditions lead them to infest books and bindings will 

 show them to be more or less well defined according to their feeding 

 habits. The book scorpions and mite, Cheyletus eruditus, which, as 

 we have seen, do not come under the head of insects, are primarily 

 carnivorous, and their presence in books may be due to the fact that 

 they find there anunal as well as vegetable food. This is certainly 

 true of the book scorpion, which feeds on mites, book lice, and other 

 small insects. The " fish moths " or " silver fish," the " book lice," and 

 the " cockroaches " can have no other reason for infesting books than 

 their liking for farinaceous substances such as are used in and about 

 the bindings and labels of books. For this reason the damage done 

 bv them is largely confined to the exterior or interior of the bindings, 

 and only so much of the book itself is injured as comes in their way in 

 their search for food. The " white ants " feed principally on wood, 

 and in and about books there is more or less wood fiber which would 

 be to the liking of these voracious feeders. The moths and beetles 

 are the burrowers and borers. They seek retired places in which to 

 lay their eggs where the larvae will be surrounded with food for their 

 growth. The moths and some of the beetles are more given to bur- 

 rowing in the bindings, keeping close to the outer surface for the pur- 

 pose, it is thought, of making it easy for the imago to emerge after the 

 change is completed; while others bore straight tunnels often from 

 cover to cover. 



A natural conclusion for one who has gone over the literature of 

 book-injuring pests to reach is that the many persons that have been 

 industriously looking for the bookworm, as well as those that have re- 

 ported the finding of isolated specimens, some dead, some alive, have 

 had in mind the one creature which bored holes in books. The fre- 

 quent use of the terms " genuine bookworm," " the real bookworm," 

 etc., reveals the fact that the users of these phrases approached the 

 subject with a preconceived idea of the kind of creature they should 

 find to account for the ravages only too apparent on scores of volumes 

 which pass through the hands of booksellers and book keepers. To 

 many the boring beetles are the only creatures which are rightfully 

 called bookworms, and in their search other book pests have not been 

 taken into account. 



