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MANUAL OF ZOOLOGY. 



The larvae of Lepidoptera (fig. 115), commonly called "cater- 

 pillars," are vermiform in shape, normally composed of thirteen 

 segments, the anterior portion forming a distinct horny head, 

 with antennae, jaws, and usually simple eyes. The mouth of 

 the caterpillar, unlike that of the perfect insect, is formed for 

 mastication. The labium, also, is provided with a tubular organ 

 the " spinneret " which communicates with two internal 

 glands, the functions of which are to furnish the silk, whereby 

 the animal constructs its ordinary abode 'or spins its cocoon. 

 The three segments behind the head correspond with the pro- 

 thorax, meso-thorax, and meta-thorax of the perfect insect, and 



Fig. 115. Goat-moth (Cossus ligniperda) and Caterpillar. 



each carries a pair of jointed walking-legs. Besides these 

 thoracic legs, there is a variable number (generally ten) of soft 

 fleshy legs, which are borne by the segments of the abdomen, 

 and are known as " pro-legs." Each is usually furnished with 

 a crown of small horny hooks, and they are never attached to 

 the 4th, 5th, loth, and nth abdominal segments. 



In the Diurnal Lepidoptera, or Butterflies proper (fig. 114), 

 the antennae are knobbed ; the wings are usually held erect 

 when the insect is in a state of repose ; the larvae have six 



