VI 



DEFENCES OF INSECTS 



211 



the world like the plant's own branches. The 

 caterpillar is long, slender, and cylindrical, it holds 

 itself stiff and immovable, so as to hide as far 

 as may be the separations of the segments, and its 

 free end where it terminates in the head one imagines 

 to be the bud at the end of a twig. Little humps or 

 tubercles likewise frequently exhibited on the body 

 pass readily for additional 

 buds or irregularities of the 

 bark, and tend greatly to in- 

 crease the resemblance. The 

 likeness is promoted by the 

 peculiar disposition of the legs. 

 While the majority of larvae 

 have five pairs of claspers, or 

 legs persistent only in the 

 caterpillar state, Geometrae 

 possess but two pairs attached 

 to their anal extremity. With 

 them the caterpillar firmly 

 grasps the stem, rendering 

 them very inconspicuous, and 

 to preclude the appearance 

 of any limbs, the pairs of true 



legs immediately behind the head in many cases are 

 applied closely to the body. The twig-like attitude 

 is abandoned solely for feeding, which as a rule takes 

 place in the evening or at night (see Fig. 35). 



On the face of it, this posture seems one impossible to 

 be borne. No creature fashioned horizontally with the 

 surface would be capable of erecting itself at an acute 

 angle with its support, and of continuing to keep the 



P 2 



FIG. 38. The hind part of the 

 larva of Brimstone Moth 

 \Rumia. cratagata)) seen from 

 the right, showing the claspers 

 and the fleshy projections which 

 tend to fill up the furrow be- 

 tween the larva and the stem ; 

 from Trans. Entoiii. Soc. 



