188 THE HISTORY OF CREATION, 
group of the Bees, or Skin-winged Flies (Hymenoptera), 
is closely allied to the four orders of biting Flies. Among 
them are those Fles which have risen to such an 
astonishing degree of mental development, of intellectual 
perfection, and strength of character, by their extensive 
division of labour, formation of communities and states, and 
surpass in this not merely most invertebrate animals, but 
even most animals in general. This may be said especially 
of all ants and bees, also of wasps, leaf-wasps, wood-wasps, 
gall-wasps, etc. They are first met with in a fossil state 
in the oolites, but they do not appear in greater numbers 
until the tertiary period. Probably these insects developed 
either out of a branch of the primeval Flies or the gauze- 
winged Flies. 
Of the two orders of Pricking Flies (Hemiptera and 
Diptera), that containing the Half-winged Flies (Hemip- 
tera), also called Beaked Flies (Rhynchota), is the older of 
the two. It includes three sub-orders, viz., the leaf-lice 
(Homoptera), the bugs (Heteroptera), and lice (Pediculina). 
Fossil remains of the first two classes are found in the 
oolites; but an ancient Fly (Eugereon) is found in the 
Permian system, and seems to indicate the derivation of 
the Hemiptera from the Neuroptera. Probably the most 
ancient of the three sub-orders of the Hemiptera are the 
Homoptera, among which, besides the actual leaf-lice, are 
the shield-lice, leaf-fleas, and leaf-crickets, or Cicadz. Lice 
have probably developed out of two different branches of 
Homoptera, by continued degeneration (especially by the 
loss of wings); bugs, on the other hand, by the perfecting 
and differentiation of the two pairs of wings. 
