Part I] Lindsay and Harlow : Lac and Shellac j 
and succulent twig, at once proceeds to settle down. This it does 
by piercing the soft bark of the twig by means of an exceedingly 
slender beak or proboscis, finer than a hair, through which it sucks 
the juices of the twig. 
Once fixed, it might be imagined that the insects had no further 
dangers to survive, except those due to enemies, but there is evidence 
to show that in the first month of their existence on the twig there 
is often a heavy mortality among them. The cause of this is 
unknown ; it may be merely constitutional weakness due to poor 
stock, over-exhaustion in finding a fixing-spot, or failure to “ strike 
oil ” in sufficient abundance for proper nourishment. Whatever the 
cause, the mortality may amount (as shown by Misra) to 25 per cent, 
of the brood, and is thus by no means negligible. Besides this loss 
after fixation, large numbers of the newly-emerged larvae frequently 
perish while still wandering in search of a fixing-spot. They are 
then very susceptible to unfavourable climatic conditions, frost, dry 
dusty winds, hail or heavy rain, while they are also carried by wind 
away from their food-plant and may in this way be removed to con¬ 
siderable distances. It is thus evident that the time of swarming, 
fixation, and the first week or two after fixation, is a critical period 
of the insect’s life ; and that the conditions that prevail during this 
period will largely influence the welfare of the brood and therefore 
its output of lac. 
The female larvae that effect a satisfactory fixation are fixed for 
life. They at once begin, by some process which is not understood, 
to produce the waxy and resinous matter known as lac, as well as a 
sugary excrement or “ honey-dew ”. This latter drips from the 
colonies on the twigs above down on to the leaves below, covering 
them with a sugary glaze that affords nourishment to a dirty-looking 
black mould. This mould has been identified by Mr. E. J. Butler, 
Imperial Mycologist, as consisting of species of Capnodium and 
Fumago , and its presence is a characteristic and easily-recognized 
mark of lac-bearing trees. The lac itself is exuded, at least mainly, 
from various glands in the skin, and that produced during this first 
stage is small in amount and very transparent. The insect, however, 
now proceeds to moult, i.e. t cast its skin, and in doing so loses its 
legs and all power of locomotion. It now becomes a pear-shaped 
sac ; where the stalk of the pear would be is an indefinite head and 
the delicate proboscis, and at the other end is a small spine and three 
[3] 
