CH. III.] INSECTS WHICH FORM COCOONS. 67 



moth [Pi/ralis {Nola, Leach) strigilata). The cater- 

 pillar is of a small size, and of a flattened form, with 

 fourteen legs, the fourth, fifth, and sixth segments 

 of the body not being furnished with feet ; it is of a 

 yellowish white colour, with a fleshy tinge, with 

 tufts of red hairs on each ring, and two brown spots 

 near the middle of the body. It was found by Reau- 

 mur in May upon the oak. This ingenious little 

 workman constructs its cocoon with an immense 

 number of small chips of a rectangular form, which 

 it gnaws from the bark of the oak, and which it fas- 

 tens together like the boards of a room-floor, end to 

 end. One of these caterpillars was brought to 

 Reaumur upon a twig, and on each side of its body 

 there was observed a thin appendage a little longer 

 than the insect's body, attached to the twig, of a long 

 triangular form. They projected at an angle from 

 each side of the twig, and somewhat resembled in 

 miniature the feathers fastened to the end of an ar- 

 row (fig. A, p. 68). The space between these two 

 wings was also of a triangular shape, and this forms 

 the basement of the insect's cocoon, the chips of 

 which the wings were formed having been gnawed 

 from it, as was perceivable from its lighter colour. 



It does not seem requisite, as Reaumur observes, 

 that nature should bestow any extraordinary degree 

 of intelligence upon an insect for the purpose of con- 

 structing an oval or rounded cocoon, that being the 

 shape in which it arranges its materials from the 

 very commencement, and to which the various po- 

 sitions of its body while at work are sufficient to 

 impart that form. But when we observe an insect 

 commencing the construction of its cocoon (which 

 when completed will resemble the longitudinal sec- 

 tion of an inverted cone, with an elliptical protuber- 

 ant base), by forming two flat and triangular walls, 

 thus adopting a mode of procedure which certainly 

 appears very unfitted for such a purpose, we must 

 at least confess, if we find that this was the plan 



