278 INSECTS. 
and so nearly allied, their classification is entirely imper- 
fect, and like a similar attempt with any other part of 
animal life, a failure. Almost every scientific writer has 
invented a system of entomological distribution for him- 
self, and their united efi'orts have produced endless con- 
fusion ; the arrangement generally followed is that of 
Latreille, the father of modern entomology. 
Insects are by him divided into two great divisions : 
those that live by chewing, oncmdibulata^ and those that 
live by sucking, haustellata, whence the name applied to 
some of the human family. Of the former the beetles, 
coleoptera, are prominent, and among the latter the 
butterflies, lejpidoptera. It is to be observed that the 
bees, although furnished with a sucking apparatus to 
collect honey, feed with mandibles, and are in the first 
class. 
Latreille further divides the various groups as follows ; 
and although English authors have made many changes, 
the alterations are of such doubtful utility that the origi- 
nal classification will be retained. 
The first class is that of insects without w'ings, such as 
the thysanura^ or those having a bushy tail, which are 
mandibulate. Parasites or lice, and fleas, both of which 
are suctional, the last having a metamorphose, but the 
first two not. All others have wings, but the second 
class includes those that have a hard covering or case, 
called an elytron, over their wings ; the beetles, which 
have a horny wing cover and perfect metamorphose ; the 
dermoptera^ which have a horny wdng cover but an im- 
perfect metamorphose ; the orthoptera^ or straight- winged 
insects, their wings folding longitudinally, and having a 
