Part I] Lindsay and Hardow : Lac and Shellac 
9 
Kusum lac is specially light and clear in colour, and is more 
highly valued than that from any other tree. Moreover, it is gene¬ 
rally accepted that brood from the Kusum tree will thrive on any 
other lac-bearing tree to which it may be transferred ; but that the 
reverse is not the case, as insects from other trees will not live on 
transfer to the Kusum tree. An explanation generally current is 
that the Kusum tree has a harder and thicker bark than other trees 
and that the Kusum insect has thus developed a stronger and longer 
proboscis which is able easily to penetrate softer and thinner barks; 
whereas the proboscis of insects from other trees is unable to pene¬ 
trate the Kusum bark. It is in the writers’ opinion more probable 
that the failure of insects from other plants to live on Kusum, if 
indeed they do fail, is due to physiological causes rather than to any 
structural weakness. 
In this connection it is interesting to find that when Kusum brood 
is transferred to the Palas tree, the first crop is known as “ Bastard 
lac ”, and it is said that its properties are intermediate between those 
of Kusum and Palas lac, while subsequent crops approximate more 
and more to the Palas variety. 
There are various statements and beliefs to be found regarding 
the relative facility with which different plants are colonizable by 
the lac insect, but they seem never to have been tested by any actual 
experimental enquiry, and there is reason to believe that at least 
some of them are mistaken. Thus lac-bearing trees still require to 
be classified in order of their suitability or unsuitability for promis¬ 
cuous propagation, if any definite order does actually exist, so that 
the brood from any tree on the list might be successfully transferred 
to any other tree classified below it, though perhaps not to any tree 
classified above it. Of the four trees mentioned above, the correct 
order on this principle is stated to be :— 
(1) Kusum. 
(2) Ber. 
(3) Ghont. 
(4) Palas. 
A further distinction, already referred to, between the Kusum and 
other trees considered as “ hosts ’* for the lac insect, relates to the 
periods of swarming. On the Kusum tree the summer brood usually 
emerges during July-August and on other trees during June-July; 
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