138 TRANSFORM A TIONS OF INSECTS. 
are classified by some naturalists amongst the Bombycina , which 
we have already noticed, and in one small family, the Hydro- 
campidce , the caterpillars live in the water, and undergo their 
metamorphosis there, one species of it being furnished with 
branchiae (“fins”). The Meal Moth, Asopia farinalis , which is 
very common in houses, is a small moth with reddish-brown 
wings, with their centres patched with fawn or grey colours. Its 
caterpillar looks as if it were varnished, and has its membranous 
legs very slightly developed. It has the curious taste of dis- 
regarding the crisp leaves of the garden, and of liking pieces of 
straw or corn, or even animal matter. These insects undergo 
a regular metamorphosis inside little silken cocoons, and the 
moths have a rudimentary trunk, and do not take any nourish- 
ment. Another moth, the Tabby, Aglossa pinguinalis , is also 
found in houses and stables. The caterpillar is of a uniform 
dark brown, with its head and front legs of a darker tint, and 
it will have nothing whatever to do with the usual food of 
Lepidopterous larvae. It has a fancy for greasy horse-cloths, 
and grease in any form ; moreover, its structures are evidently 
suited for its love of fatty matters. The caterpillar sticks 
itself into the grease bodily, and without danger of being 
suffocated, for its spiracles are covered by folds of the out- 
side skin, which prevent the grease and fat from blocking 
them up. It is always interesting and instructive to notice 
how Nature provides for the well-being and safety of living 
things existing under extraordinary circumstances, and it is 
important to remember that horse-cloths, grease, and kitchen 
fat are productions of a more or less recent civilisation, and 
that these moths obtained their peculiarities, which always 
descend generation after generation, after the invention of this 
greasy nastiness. They are either new species which have 
become evolved from others, which led different lives before 
horse-cloths were invented, or else they were specially created 
to relieve the world of much fat, and things we don’t care 
about. Which of the two origins is the correct one must be 
left to the intelligence of all the good people who, if they are 
not very well qualified to give an opinion upon the origin of 
species, never hesitate to do it. 
