1 
For example : A number of species possess the power of leaping, 
most of which have the antenn;e terminated by two minute bristles, in 
both of which respects they differ from all the other species; some are 
always found more or less covered with a whitish, cottony or downy 
substance, while others are always naked; some possess little horn-like 
appendages, called “honey tubes,” arising from the upper part of the 
abdomen near the tip, while others are entirely without these; some 
have the very singular habit of bringing forth their young alive, while 
others are always oviparous; some confine their operations exclusively 
to the leaves, others to the twigs and bark, and others to the roots, 
while others operate both on the stem and root or leaves and roots; 
some reside exposed on the surface of the leaves or bark, while others, 
by some peculiar power, not yet understood, form galls in which they 
carry on their operations and pass the greater portion of their exis¬ 
tence; in most cases the pupae are active as the perfect insects, yet 
there are some species in which these are stationary, and resemble the., 
apparently lifeless scale of the bark-life. 
Most of the species, at some period of the year, present winged 
individuals of one or both sexes, yet their habits in this respect are 
widely different, and the differences between the wings of the various 
species afford some of the best characters yet observed for separating 
them into generic or larger groups. 
For example: In a very large portion, in fact in mos j of our Ameri¬ 
can species, the wings are very thin and membranous and almost 
perfectly transparent, while in one very singular group they are opaque 
and more or less covered with a fine powder, giving them the ap¬ 
pearance of minute moths. Very marked differences are found in the 
veining of the transparent wings of the former; in some the rib-vein 
or chief vein of the fore-wings is central; and as it proceeds towards 
the apex divides into branches, each of which is again divided; while 
in another very large group the rib-vein coasts along near the front 
margin, giving off on the posterior or inner side three bunches which 
run obliquely outward and backward to the hind margin; some 
have the third or outer branch twice forked, others once, while in 
others it is simple or unbranched. Some species place their wings, 
when in repose, against each other, above the back, in the form of a 
very steep roof, while others rest them horizontally on the abdomen. 
Some have the antennae as long or even longer than the body, while 
in others these organs do not reach the middle of the thorax; these 
organs, when tipped with two bristles are nine or ten (usually ten) 
jointed, in all other cases they are seven or less than seven-jointed, in 
many species they are six-jointed, in quite a number five-jointed and 
in one generic group but three-jointed. 
Some of these differences will doubtless be considered unworthy of 
notice by those who have never devoted any time to the study of in¬ 
sects and their characters; but when it is found by close and persis¬ 
tent study of the habits of these insects that the difference in the 
number of forks of one of the branch or discoidal veins is always ac¬ 
companied by a marked difference in habits, this character, although 
apparently insignificant, is really important. A knowledge of these 
facts enables the encomologist, if he can see but a single tiny fore wing, 
to tell at once to what group the species belongs and what are its 
habits. 
