DOMESTICATED INSECTS 259 
There unfortunately appear to be no means of ascertaining 
how far British apiculture is profitable. Honey to the value of 
£30,349 was imported into this country in 1903. 
Tue Sitx-Worm Mora (Bompyx mort, &c., fig. 1189).—The 
most important and best-known kind of Silk- Worm Moth is the one 
(Bombyx mort) of which the caterpillar or ‘ silk-worm” feeds upon 
the leaves of the mulberry- 
tree. The life-history is 
sufficiently familiar. From 
the egg a minute larva 
hatches out which is full 
grown in about five weeks, 
during which time it casts its 
skin several times. At the 
end of this period the silk- 
worm spins a cocoon, which 
consists of two long threads, 
the hardened secretion of 
two large glands that open 
on the under-lip. 
The material known as 
“cat-gut” is made from the 
secretion of the silk-glands, 
which are removed from 
the caterpillar and subjected 
to suitable treatment. 
The culture of silk-worms 
is generally supposed to 
have been first practised in 
China, the first allusion to 
it dating back to 2640 B.c., 
according to Chinese re- 
cords. Thence the industry spread through Korea into Japan, 
and also into India, Persia, and Central Asia. Its introduction into 
Europe is ascribed to the Emperor Justinian, who is said to have 
induced a couple of Persian monks to undertake a journey to China 
with the view of surreptitiously obtaining eggs. These worthies 
are stated to have been successful in their mission, reaching Con- 
stantinople with a supply of eggs (concealed in bamboos) in the 
year 550 A.D. To this source the silk-industry of Southern Europe 
Fig. 1189.—Silk-Worm Moth (Bombyx mori). a», Caterpillar 
(silk-“‘ worm”); B, female moth; c, cocoon, 
