52u Annual Report of New York 
merits of nature, whereby creatures which have no means of defense, 
usually no power to spring or fly or other resort whereby to escape 
from their enemies, are able to take on such an appearance as will 
cause them to be overlooked and passed by unharmed. But for this 
they would soon be exterminated. 
It is most frequently some of the common parts or appendages of 
shrubs and trees which are imitated. Different kinds of small insects 
are accustomed to station themselves in the axils at the base of the 
leaf-stalks, where they appear like the buds growing at these points. 
The larvae of the different lappet-moths so closely resemble the bark 
of the trees on which they respectively feed, as to be quite invisible 
when they are at rest. Many of the measure-worms have a habit 
which most persons have noticed. Fixing themselves to a limb by 
their hind pair of feet, they hold their bodies outward therefrom, 
straight and stiff, remaining motionless in this position for many 
hours, their slender cylindrical form and dull colors giving them a 
most perfect resemblance to a dead twig branching from the limb. 
Without adverting to other instances of this mimicry we return to 
this lilac measure-worm, and remark that in its young state, when 
suspended from the under side of a leaf with the middle of its body 
bent into a semi-circle, it is sui generis in its appearance, looking like 
no other object in nature with which I am acquainted, and the cluster 
not in the least resembling an assemblage of worms. But when it is 
grown to a larger size and the whole family is hanging suspended 
from the twigs of a leafless limb, they present a counterfeit which is 
so perfect and striking that it is at once recognized. They then 
have the exact aspect of the brown aments or unopened staminate 
flowers of the alder, the poplar and other analogous trees which put 
forth their flowers in early spring when the limbs are destitute of 
leaves. Whoever is familiar with the appearance of these pendant 
tassels as they occur upon the alders growing along our streams of 
water will at a first glance be struck with the close resemblance of 
these lilac worms to them. The similitude will be noticed in all their 
details ; their 6ize, their form, their position, their brown color, the 
projecting teeth along the sides of their backs appearing as the ends 
of the opening scales of the aments, and to crown all, the three bright 
yellow spots upon each side of the worms are a perfect counterfeit of 
some of the yellow anthers of the flowers beginning to protrude from 
between the scales. And we further observe that a portion of the 
aments of the alder grow in pairs, and in a company of these worms 
hanging from the twigs and leaf-stalks, here and there two will he 
