30 PARTIAL OKISMOLOGY. 



of the head occurs only in the maggots, which are destitute of all the 

 organs observable in the heads of caterpillars, such as antenme, eyes, 

 &c. ; but there are to be seen, in the anterior opening which forms the 

 mouth, two horny bristles, which seem to represent the mandibles, which 

 serve for the destruction of its prey, when, for instance, the maggot 

 feeds upon other insects. In larvae and caterpillars, however, the 

 whole head is covered by a peculiar corneous case, which is divided into 

 two by a perpendicular suture descending from the vertex, and 

 separating in a fork just above the mouth. The general form of this 

 covering is more or less round, resembling a hemisphere ; in many 

 instances it has a triangular, and often a complete heart-shaped figure 

 ( Sphinx Ligusl.ri, Smerinthus Popu/i, and many others); sometimes 

 each half is produced at the vertex into a pyramidal process (Apatura 

 Iris, PI. II. f. 16), or the whole superior part of the head is completely 

 covered with thorns and spines (Limenitis Amphinome, PI. II. f. 15). 



As peculiar organs of the head of larvae, we must notice the oral 

 apparatus, the antennae, and the eyes. All true caterpillars have 

 mouths adapted to manducation, as have also all larvae with horny legs, 

 and, indeed, many without legs. The mouth is discoverable at the 

 anterior or inferior contracted portion of the head ; it is formed by the 

 Mat, longitudinally quadrate ( sometimes taking the shape of a segment 

 of a circle) corneous upper-lip, or LABRUM (labrum, PI. II. f. 13, ) ; 

 the equally strong corneous, horizontally-moving- upper-jaws, or MANDI- 

 BLES (mandiiiulas, PI. II. f. 13, A, b) ; the weaker, but very similar, 

 under- jaws, or M AXILLAE (rnaxillce, c, c), with their feelers, or PALPI 

 (palpi), and the likewise flat, more or less triangular, horny under-lip, 

 or LABIUM (labium, d), which also is very generally furnished with 

 short FEELERS, or palpi; and this under-lip, or labium, closes the mouth 

 from below, as the labrum does from above, whilst the closed mandibles 

 completely shut the orifice in front. All these organs are also found 

 in the perfect insect, and we shall consequently describe them more in 

 detail when we arrive at that stage of its existence. 



The ANTENNA (antenna, f, f) are placed near the mouth, at the 

 base of the mandibles and maxillse. In larvae they consist of but few, 

 generally but three joints, or short narrow corneous cylinders, united 

 together by a delicate skin. They are always of a bristly or filiform 

 shape, even when the antennae of the perfect insect are very differently 

 constructed ; for in caterpillars they present themselves as very short 

 conical processes, while in the butterflies, which proceed from them, 

 the antennae are very long, and many-jointed. 



