THE LAEYA. ^ 17 



liave their heads covered with the same flexible mem- 

 branous skin that is spread over the rest of the body, but 

 they make amends for this in the power they possess of 

 changing the form of the head into different shapes, or 

 extending and contracting it at wilL The head is generally 

 a little narrower than the rest of the body, though in some 

 lepidopterous larvae it bears no proportion whatever to the 

 diameter of the other rings. At its first exclusion from the 

 egg the head is the largest part of the larva, but it rarely 

 continues so. It is either naked or uncovered as the rest 

 of the body, unless, with small spines or prickles, its most 

 common color is a reddish brown, or a darker shade than 

 the other parts. Sometimes, as among the larvae of some 

 butterflies, beetles and two-winged insects, the head can 

 be wholly or nearly withdrawn within the first segment of 

 the body. 



Eyes. — The larvse of many insects have no eyes ; of such 

 are the lamellicorn and Capricorn beetles, and all those 

 among the two-winged insects that have a membranous 

 or variable head. 



Those that are said to have simple eyes have one, two, 

 or, perhaps, three on each side of the head. While, when 

 there are groups or bunches of five, six or more on either 

 side, we may call them compound eyes. The structure of 

 these does not differ materially from those of the perfect 

 insect, in connection with the study of which they will be 

 considered more at length. 



The antennce are feelers or projecting filaments from the 

 heads of insects or larvse. Many are without them alto- 

 gether, as the larvae of most of the two-winged insects 

 some of the beetles, the bees, wasps, etc., but the larvae of 

 the greater number of insects are provided with antennae. 



