+ BUTTERFLIES AND MOTHS. 
The mouth-parts of moths and butterflies are only 
adapted for sucking nectar from flowers, and not for chew- 
ing their food. The main part is along sucking-tube (Fig. 
7, h), composed of two greatly eiongated maxillze fastened 
together side by side; as each maxilla is furnished witha 
Fig. ec cier: Peete eye; h, tongue; /, labial 
groove the two maxille fastened together form a perfect 
tube by means of which the liquid food is conveyed to the 
mouth and stomach. Usually this tongue is quite smooth, 
but in some cases its tip is furnished with spines, which 
enable the insect to rupture the skin of ripe fruit to obtain 
its juice. As many moths do not eat they lack a tongue, or 
possess only a rudimentary $ne. This important organ, 
when not in use, is curled up like the mainspring of a watch, 
and is hidden and protected by the labial palpi (Fig. 7, J), 
which for this purpose project forward. Moths and but- 
terflies, in extracting nectar from flowers, become very use- 
ful in pollenizing them; some plants, indeed, have to depend 
altogether upon these insects for their continued existence. 
The compound and unmovable eyes (Fig. 7, a) of lepido- 
ptera, are large and composed of many small facets, each 
of which isaperfect eye. This arrangement enables the insect 
to look in many directions at the same time. These com- 
