CHAPTEE XVI. 



THE BOOK-LOUSE AND SILVER-FISH INSECT. 



To all who have the care of collections of insects or 

 other natural history specimens, there has come, at some 

 time or other, the vexation of seeing on the bottom of 

 drawers or store-boxes some swiftly running, almost 

 transparent, but exceedingly minute, insects, rushing 

 about from one specimen to another, playing hide-and- 

 seek, as it were, under them, in a manner most provoking 

 to their owner. They are there for no good purpose, 

 and must be ruthlessly hunted to death, for they are 

 the destructive creatures known as book-lice (Atropos 

 divinatoria), an extremely familiar and much-detested 

 pest. Without strenuous and persistent efforts it is 

 impossible to protect specimens, whether animal or 

 vegetable, from their depredations; and though so 

 minute, Atropos is none the less capable of causing serious 

 damage if allowed to go on its way unchecked, as many 

 have found to their cost, who have permitted the 

 quarantining of their collections to be intermitted for a 

 time. Its popular name is a somewhat unfortunate one, 

 since the suggestions of unpleasant associations which it 

 conveys are altogether unfounded in fact. The little 

 creature is not parasitic, and becomes a pest solely by 

 reason of the readiness with which it will attack and 

 devour anything that is in the least degree edible. It 

 is a widespread and common inhabitant of houses, there 



