CLASS IXSECTA. 



43 



like organs (fig. 17, D, an), which are called the " feelers " 

 or " antennae" (Latin, antenna, the yard-arm of a ship), 



Fig. 17.— A, One of the Dragon-flies {JSshna grandis), slightly dissected ; h 

 Head, caixying the eyes, antennae, and organs of the mouth; t, t', t" First, 

 second, and third segments of the thorax slightly separated from one 

 another, each carrying a pair of legs, and the two last carrying each a 

 pair of wings; a Tail or abdomen. B, Young form, or " larva," of the 

 same. C, Second stage, or " pupa." D, Head of a Dragon-fly {Libelhda 

 depressa), showing the feelers or antenna {an), the eyes (e e), the hinder 

 pair of jaws (m), and the upper lip (/). 



and which no doubt are employed by the insect as organs 

 of touch, and perhaps as organs of hearing as well. Upon 

 its under surface, lastly, in front, the head carries the 

 mouth, surrounded by the lips and jaws. These need 

 not be particularly described, beyond saying that they 



