INSECTA. 253 
the ox. The fleas form a modified type of the Diptera, 
with the wings reduced to mere rudiments, a loss of motor 
organs characteristic of parasites. 
OrvER IV.—Lepidoptera. 
The metamorphosis is complete. The mouth parts are 
adapted for ‘‘sucking,” and there are two pairs of large 
opaque wings which are covered with minute scales. In 
this order are included the “butterflies” and “moths.” 
The mouth parts are much modified. The mandibles are 
mere vestiges, and the maxilla are produced into a long 
NRE 
Female depositing eggs, larva (caterpillar), and pupa, 
spirally-coiled ‘ proboscis,” composed of two half-cylinders 
apposed together. The labium is small and bears a pair 
of fairly large labial palps ; the maxillary palps are vestigial. 
In use the proboscis is uncoiled and thrust into flowers, 
nectar being sucked up its interior. 
The wings are covered with minute scales of varying 
shape which are easily rubbed off when the membranous 
wing is exposed. As a general rule butterflies or moths 
have bright colours on the upper surface of the wings, and 
sombre protective colours below (cf Chap. IX.). 
The larva is a ‘‘caterpillar” which often executes great 
destruction amongst plant-life. 
