INSECTS : THEIE EABS AND EYES. 163 



Skipjack (Elater), but many members of the same family 

 show the same structure in a far higher degree, the angle 

 being drawn out into a long slender rod, which (with its 

 fellows) imparts to the antenna the appearance of a 

 comb. 



But much more curious and beautiful are the antennae 

 of many moths, which often resemble feathers, particularly 

 in the group Bombycina, of which the Silkworm is an 

 example ; and in the male sex, which displays this struc- 

 ture more than the female. But I will show you a native 

 example. 



This is the antenna of a large and handsome, and not 

 at all uncommon moth — the Oak Egger (Lasiocampa 

 querc&s). It consists of about seventy joints, so nearly 

 alike in size and outline, that the whole forms an almost 

 straight rod, slightly tapering to the tip. Each joint, 

 however, sends forth two long straight branches, so dis- 

 posed that the pair make a very acute angle, and the 

 whole double series of seventy on each side, form a deep 

 narrow groove. These two series of branches, being per- 

 fectly regular and symmetrical, impart to the antennas the 

 aspect of exquisite feathers. 



It is, however, when we examine the elements of this 

 structure in detail, using moderately high powers of 

 enlargement, that we are struck with the elaborateness of 

 the workmanship bestowed upon them. Each of the 

 lateral branches is a straight rod, thick at its origin, 

 whence it tapers to a little beyond its middle, and then 

 thickens again to its tip. Here two horny spines project 

 from it obliquely, one much stouter than the other, at 

 such an angle as nearly to touch the tip of the succeeding 

 branch. 



Besides this, each branch is surrounded throughout its 

 length with a series of short stiff bristles, very close-set, 

 projecting horizontally (to the plane of the axis of the 

 branch), and bent upwards at the end candelabrum-fashion. 



m 2 



