INTRODUCTION. 
.'51 
puscularia by LatreiUe. The latter term has been 
applied to them, because many of the most conspicu- 
ous species are observed on the mng chiefly during 
the morning and evening twiUght ; others, however, 
do not shim the “ garish eye of day,” but may be seen 
darting about in the sunshine in company with but- 
terflies and other exclusively diurnal kinds. Their 
flight is exceedingly rapid, and continued nearly in a 
direct line, somewhat like that of a bird, differing 
greatly hi this respect from the devious zig-zag motion 
of most other lepidoptera, many of which seem to 
^at rather than to be impelled by muscular exertion. 
The nnngs, notwithstanding, are rather of small size 
compared with the body ; but the thickness and mas- 
siveness of the latter admits of great development in 
the muscles by which these organs arc moved, and 
a momentum is thus communicated to them more 
than sufficient to compensate for their somewhat 
limited extent of surface. By their rapid vibration, 
the taper body ofthe insect is poised in the afr like 
that of a hawk, wlule it hovers over the petals of a 
flower, and extracts the mellifluous juices by means 
of its long tubular proboscis. The resemblance just 
alluded to has caused them to be named hawk- 
motbs ; and as many of them, when thus hovering 
in the air, produce a humming sound, and in this 
respect, as well as in feeding on the wing and in the 
darting rapidity of their movements, bear some like- 
ness to humming-birds, a few are named after these 
“ winged gems,” and are well known under the some- 
what composite title of hiumnmg-bhd hawk-moths. 
