86 
INTRODUCTION TO 
moss, or stones, the eaves of out-houses, and similar 
places, are industriously sought after, and many bury 
themselves a considerable depth in the earth. But 
the selection of a suitable retreat is far from being 
their only care, at least with a great many ; other 
precautions are resorted to, many of which afford 
examples of singular ingenuity and persevering labour. 
This is particularly the case with the caterpillars of 
butterflies and moths. The former either suspend 
their chrysalides horizontally by the tail and a silken 
band round the middle, or by the tail alone, allowing 
the body to hang perpendicularly. The manoeuvres 
by which the caterpillar manages to place the band 
round its body are extremely curious and interesting, 
and have, therefore, been particularly described in the 
volume of this series already mentioned and to which 
we must again refer. The cocoons of moths have 
likewise been described in a similar volume de- 
voted to their history ; and that tribe of insects af- 
fords the best examples of this species of fabrication. 
Most of the Hymenoptera likewise form silken 
cocoons ; a few Coleopterous and Dipterous genera, 
(Hypera, Donacia, Mycetophila,) and the Neurop- 
terous groups Hemerobius arid Myrmeleon ; the latter 
differing from nearly all the rest in having the ap- 
paratus for spinning their threads at the extremity 
of the abdomen, instead of in the head. Cocoons of 
silk are often strengthened by the addition of other 
materials, such as particles of earth, portions of leaves, 
fragments of wood, &c . ; and occasionally cocoons are 
formed altogether of these substances held together by 
