LAC. 
33 
Sub-section 2a, Lac. 
(By E. E. Green, Government Entomologist.) 
Strictly speaking, lac is not a vegetable economic product, 
but as it is a resin and collected upon plants it is con¬ 
venient to include it here. 
Lac is not—as sometimes supposed—a resinous exudation 
from a tree, excited by the punctures of the insect that 
accompanies it. The juices of the plant first pass through the 
body of the insect, and reappear as an excretion from the 
skin. The resinous matter first occurs in the form of 
separate plates on the dorsal area of each segment of the 
larval insect. As the insect grows these plates enlarge, 
coalesce, and thicken ; finally forming a hard compact shell 
completely enclosing the insect, but perforated by three 
small holes—known as the spiracular (2) and anal (1) orifices. 
Where the insects are much crowded on a branch—as usually 
occurs—the resinous cases become agglomerated, resulting 
in a continuous incrustation enclosing the branch upon 
which it is formed. In this condition it is known as 
“ Stick-lac.” “ Seed-lac ” consists of the resinous matter 
removed from the branches and broken up. “ Shell-lac ” is 
the residue after evaporation of an alcoholic solution of the 
resin. 
The lac insect is a Coccid or scale-insect, belonging to the 
genus Tachardia. Many species of Tachardia are known to 
science, but only a few of them are of any economic value. 
The principal source of commercial lac is Tachardia lacca , 
a native of India. 
THE LAG INDUSTRY IN CEYLON. 
Lacwork, or lacquerwork, appears to be a dying industry in 
Ceylon. 
There are two distinct classes of work : one in which the lac- 
pigments are applied to the wood while it is revolving on a turning- 
lathe, the heat of friction causing the lac to adhere : and another in 
which the pigments are heated over a charcoal fire during application. 
The first class of.work is applicable only to articles that can be turned 
F 
[October, 1903.] 
