Book-Lovers. 87 
by foot or hand to crush the life that dares obtrude its 
uncleanly presence in her larder, but the cunning, swift- 
footed Lepisma darts off, like a streak of light, to some 
near-by crack or breach, where it manages to hide from 
threatening danger. The bodies of these nimble, silent- 
moving creatures being coated in a suit of shining mail, 
which the arrangement of the scales so very much resembles, 
they have a weird and ghostly look. This appearance, and 
the swiftness of their movement, which the eye can hardly 
trace, have led the vivid mind of man, in country town and 
village, to dub them “silver witches.” 
So fleet of foot are they, and so like a wave of blurred 
light they cross the vision, that it is vain to try to figure 
what they are in shape and look. In death they yield their 
all of earth to prying science. Their body’s form is narrow, 
flattened; their legs in pairs of threes, each of six joints 
consisting, the basal joints broad, flat, triangular, the tarsal 
large, in number two, and armed at end with pair of claws 
incurved. The three thoracic segments are very like in size, 
and eight abdominals, of similar length and width. So weak 
it seems the rather long abdomen is, that two pairs or six of 
bristles, simple, unjointed, and freely movable, serve as 
support, and also, as in other groups of insects, as organs 
locomotive. 
The mode of antenna-insertion—and the same prevails in 
the entire family—is much like that of the Myriopods, the 
front of the head being flattened and concealing, as in the 
Centipedes, the base of the antenne. Indeed, the head of 
any of the Bristle-tails, as seen from above, bears a general 
resemblance in some of its features to that of the Centipede 
and its allies, and so, in a less degree, does the head of 
the larve of certain beetles and neuropters. The eyes are 
compound, the individual facets constituting a sort of heap. 
The mouth-parts are readily compared with those of the 
larva of Perla, the rather large, stout mandibles being hid at 
their tips by the upper lip, which moves freely up and down 
