- THE EYES. 39 



As to length, they are very long compared with the 

 length of the body, in some moths and beetles, and 

 very short in the house fly ; but their length does not 

 depend on the number of the joints, for they may be 

 long, when composed of only three or four pieces, and 

 short, when composed of ten or more pieces. 



As to form, they are either cylindrical, conical, 

 bristle-shaped, awl-shaped, spindle-shaped, forked, 

 branched, feathered, tiled, beaded, (like a neck-lace), 

 pectinated, (like a comb), serrated, (like a saw), prism- 

 shaped, downy, hairy, or bristly. Their tips again are 

 either pointed, knobbed, clubbed, hooked, triangular, 

 leaved ('), (as in the dung beetle), forked, blunt, 

 awned ( 2 ), abrupt, or perforated. 



In the males of moths, gnats, and some other in- 

 sects, the ears are in all or most cases more orna- 

 mented with feathers, hairs, or sculpture, than in the 

 female, in which the ears are plain. 



The Eyes of Insects. 



In the larger animals, there is only one sort of eyes, 

 but insects have two sorts, veiy different in structure, 

 which have been called simple and compound, there 

 being always two compound eyes ( 3 ), placed near the 

 base of the ears on each side of the forehead or face ; 

 but the simple eyes( 4 ) vary in number, and are placed 

 higher up, usually on the crown of the head, as in 



(1) In Latin, Lamellate. 



(2) In Latin, Aristatee. 



(3) In Latin, Oculi compositi. 



(4) In Latin, Ocelli, or, very objectionably, Stemmata. 



