LEPIDOPTERA. 331 



which this genus belongs. In the Hawk-moths the frenu- 

 lum is usually well preserved, but in a few it is wanting or 

 rudimentary. In many genera vein III, of the fore wings 

 coalesces with vein III 3 to its tip, so that vein III is only 

 four-branched. 



Some of the Hawk-moths are small or of medium size ; 

 but most of them are large. They have the most powerful 

 wings of all Lepidoptera. As a rule they fly in the twilight, 

 and have the habit of remaining poised over a flower while 

 extracting the nectar, holding themselves in this position by 

 a rapid motion of the wings. This attitude and the whir of 

 the vibrating wings gives them a strong resemblance to hum- 

 ming-birds, hence they are sometimes called Humming-bird 

 Moths ; but they are more often called Hawk-moths, on ac- 

 count of their long, narrow wings and strong flight. 



Of all the beautifully arrayed Lepidoptera some of the 

 Hawk-moths are the most truly elegant. There is a high-bred 

 tailor-made air about their clear-cut wings, their closely fitted 

 scales, and their quiet but exquisite colors. The harmony of 

 the combined hues of olive and tan, ochre and brown, black 

 and yellow, and grays of every conceivable shade, with touches 

 here and there of rose color, is a perpetual joy to the artistic 

 eye. They seldom have vivid colors except touches of yel- 

 low or pink on the abdomen or hind wings, as if their fas- 

 tidious taste allowed petticoats only of brilliant colors always 

 to be worn beneath quiet-toned overdresses. 



The larvse of the Sphingidae feed upon leaves of various 

 plants and trees, and are often large and quite remarkable 

 in appearance (Fig. 408). The body is cylindrical and 

 naked and usually has a horn behind near the end of the 

 body on the eighth abdominal segment. Sometimes instead 

 of the horn there is a shiny tubercle or knob. We cannot 

 even guess the use of this horn, unless it is ornamental, for 

 it is never provided with a sting. These caterpillars when 

 resting rear the front of the body up in the air, curl the 

 head down in the most majestic manner, and remain thus 



