230 
MOTil. 
But of all the Moths of the tribe Bombyx the 
Phalceua Mori or Silkworm Moth is by far the 
most important. This is a whitish Moth, with a 
broad pale-brown bar across each of the upper 
wings. The caterpillar or larva, emphatically 
known by the title of the Silkworm, is, when full 
grown, nearly three inches long, and of a yellow- 
ish grey colour: on the upper part of the last 
joint of the body is a horn-like process, as in 
many of the Sphinges, It feeds, as every one knows, 
on the leaves of the white Mulberry, in defect of 
which may be substituted the black Mulberry, 
and even, in some instances, the Lettuce and a 
few' other plants. The Silkworm remains in its 
larva state about six weeks, changing its skin four 
times during that period, and, like other cater- 
pillars, abstaining from food for some time before 
each change. When full grown the animal en- 
tirely ceases to feed, and begins to form itself a 
loose envelopcment of silken fibres in some con- 
venient spot which it has chosen for that purpose, 
and afterwards proceeds to enwrap itself in a 
much closer covering, forming an oval yellow 
silken case or ball about the size of a pigeon’s 
egg, in which it changes to a chrysalis, and after 
lying thus inclosed for the space of about fifteen 
days, gives birth to the Moth. This however is 
always carefully prevented when the animals are 
reared for the purpose of commerce, the Moth 
greatly injuring the silk of the ball by discharging 
a quantity of coloured fluid before it leaves the 
cell: the silk-balls are therefore exposed to such a 
