2 FARMERS’ BULLETIN 681, 
through the leaves and covers. It appears to the naked eye a small, glittering, pearl- 
colored moth, which upon the removing of books and papers in the summer, is often 
observed very nimbly to scud and pack away to some lurking cranny where it may 
better protect itself from any appearing dangers. Its head appears big and blunt, 
and its body tapers from it toward the tail, smaller and smaller, being shaped almost 
Jike a carret.! 
HABITS AND INJURY. 
On account of its always shunning the light and its ability to run 
very rapidly to places of concealment, it 1s not often seen and is most 
difficult to capture, and being clothed with smooth, glistening scales, 
it will slip from between the fingers and is almost impossible to secure 
without crushing or damaging. It is one of the most serious pests in 
libraries, particularly to the binding of books, and will frequently eat 
off the gold lettering to get at the paste beneath, or, as reported by 
the late P. R. Uhler, of Baltimore, often gnaws off white slips glued 
on the backs of books. Heavily glazed paper seems very attractive 
to this insect, and it has frequently happened that the labels in museum 
collections have been disfigured or destroyed by it, the glazed surface 
having been entirely eaten off. In some cases books printed on heavily 
sized paper will have the surface of the leaves a good deal scraped, 
leaving only the portions covered by the ink. It will also eat any 
starched clothing, linen, or curtains, and has been known to do very 
serious damage to silks which had probably been stiffened with sizing. 
Its damage in houses, in addition to its injury to books, consists in 
causing the wall paper to scale off by its feeding on the starch paste. 
It occasionally gets into vegetable drugs or similar material left undis- 
turbed for long periods. It is reported also to eat occasionally into 
carpets and plush-covered furniture, but this is open to question. 
STRUCTURE AND RELATIONSHIPS. 
The silverfish belongs to the lowest order of insects—the Thysa- 
nura—is wingless, and of very simple structure. It is a wormlike 
insect about one-third of an inch in length, tapering from near the head 
to the extremity of the body. The head carries two prominent an- 
tenne, and at the tip of the body are three long, bristle-shaped 
appendages, one pointing directly backward and the other two ex- 
tending out at a considerable angle. The entire surface of the body 
is covered with very minute scales like those of a moth. Six legs 
spring from the thorax, and, while not very long, they are powerful 
and enable the insect to run with great rapidity. 
In certain peculiarities of structure, and also in their habits, these 
anomalous insects much remind one of roaches, and their quick, 
gliding movements and flattened bodies greatly heighten this resem- 
blance. More striking than all, however, is the remarkable develop- 
ment of the cox or basal joints of the legs in the silverfish, which 
1 Hooke, R., Micrographia, p. 208-210. London, 1665. 
