7 
Part I] Lindsay and Harlow : Lac and Shellac 
of the tract such as Damoh, can be avoided on the hill slopes, and 
hail, heavy tropical rains and dry hot winds are uncommon. 
Point number four, relating to the enemies of lac, is the only 
one where a reasonable amount of accurate information is already 
available, and we owe this chiefly to the work of Imms, Chatterjee, 
and Misra. These observers are unanimous in attaching serious 
importance to the destruction of lac insects by natural enemies and 
parasites, and no one who has raised lac under observation is likely 
to disagree with them. Useful work has been done in identifying 
some of the more important parasites of the lac insect, but compara¬ 
tively little is known regarding their habits, life-histories and distribu¬ 
tion, or their relative destructiveness and the best means of combating 
them. 
These four points are considered in a rather broader and more 
general sense in Appendix III on “ Research ”, but it is as well that 
we should realize at the outset how very patchy and superficial our 
knowledge is as regards what may be called the biological side of 
the study of lac, that is to say, the side which deals with the two 
living organisms concerned, the lac-insect and its food-plant; the 
nature of the relations that exist between the insect and the plant, 
or between different varieties of insect and plant, the nature of the 
substances from which the insect elaborates its lac, the physiological 
process by which it performs this remarkable operation, the effect of 
climatic and other conditions on the plant, insect, and lac-production, 
and the methods of protecting either plant or insect from the many 
enemies that beset and injure them. 
Although, as we have said, the information at our disposal on 
most points connected with the insects and “ host ”-trees they feed 
on is fragmentary, and a good deal of it untrustworthy, it may be 
permissible to draw attention to a few miscellaneous matters that 
are of biological and practical interest. 
One may say that the produce of the lac-insect is as follows :— 
(1) Lac, consisting of a complex of resinous substances and 
waxes, the amount of waxy matter being less than io 
per cent. There is also a little colouring matter pre¬ 
sent. 
(2) Lac-dye , consisting of at least two dye-stuffs, and almost 
entirely concentrated in the body of the insect and its 
eggs or young. 
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