372 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1939 



Cockroaches and silverfish are world-wide in their distribution. 

 They can seriously deface book covers but rarely do more, even when 

 most abundant. They do not eat into the pages of books: they eat 

 the sizing out of book covers. If these are of paper, the insects may 

 actually devour the paper itself as indicated in plate 7, where an 

 envelope is shown ruined by silverfish. But usually both silverfish 

 and cockroaches confine their attack to removing the sizing from 

 cloth bindings as indicated in plate 2 or to eating off labels pasted 

 onto books or files (pi. 13, c). The large American cockroaches may 

 become very destructive in closed library spaces and may actually eat 

 off the backs of cloth-bound books (pi. 13, a). Cockroaches emit an 

 inklike liquid which further defaces books (pi. 13, b). No one can 

 sympathize with the librarian in northern climates who permits cock- 

 roaches and silverfish to deface books, for the presence of these insects 

 in numbers is the result of neglect for which there is no excuse. But 

 in tropical areas, or even in the Gulf coast States, where cockroaches 

 and silverfish are abundant ever3^where outdoors as well as indoors, 

 the protection of books from defacement is a continuing battle that 

 is won only by eternal watchfulness and application of remedial 

 measures. 



Termites have ruined more books than any other group of book 

 insects. There are two kinds, the subterranean and the dry-wood 

 termites, which, however, look veiy much alike (pi. 3, a, c). Because 

 the worker forms, which cause injury, are creamy white in color, they 

 are frequently called "white ants," although they are very distinct 

 from true ants, which do not harm books. Termites are never seen 

 running about over books and furniture unless their feeding cham- 

 bers have been broken open. The subterranean forms are so called 

 because they must maintain contact with the moisture in the soil be- 

 neath the building in which they are causing destruction. In modern 

 libraries built with the intention of "building termites out" and 

 equipped with metal shelving, the subterranean termites cause no 

 harm. It is true that cracks in basement floors and side walls may 

 offer entry to subterranean termites even into buildings thought to 

 be termite-proof, but it requires little inspection to guard against 

 such attack. Usually, subterranean termite destruction takes place 

 in libraries in wooden buildings with books stored on wooden shelv- 

 ing. In private homes, or in public institutions that store valuable 

 old records in basement rooms, or even on first-story floors, termites 

 may attack with a suddenness that is astonishing. Their natural 

 food is wood, which is cellulose, but the pages of many books are also 

 cellulose. Private collections of books left packed in wooden boxes 

 over wooden basement floors infested with termites have been ruined 

 during a four-months' storage period. Types of injury caused by 



