8 
Indian Forest Recoids. 
[ VOL. I. 
differ to a greater or less extent according to the degrees of heat or 
moisture, or of both, experienced in the locahties they inhabit. It will be 
necessary here, therefore, to give a general life history of the lac insect 
to begin with, subsequently detailing the variations in the number of 
broods, times of appearance, etc., appertaining to different parts of the 
continent. 
The insect usually passes through two generations in the year, although 
there may, in some parts of the country, be a third. The periods at which 
the yoimg larvae are seen to swarm upon the trees are about the first week 
in July and again in the first week in December or even as late as Jan- 
uary. 
Commencing with the July generation the first of the minute red 
larvae swarm out of the dried-up shelly incrustation about the beginning 
of the month and spread over the neighbouring twigs of the tree, these 
latter assuming a reddish colour owing to the countless numbers of 
hving larvae moving over them {vide PI. II, figs. 1 and la). The larvae 
do not aU hatch out from the eggs at once, but apparently continue to 
emerge for as long as a month after they first appear. One effect of this is 
that it ensures some of the young ones living should the weather prove 
inclement during the hatching out of any portion of the brood. The 
larva on leaving the incrustation crawls on to a neighbouring twig and 
searches for a suitable soft sappy part, and then, piercing through the 
cortex, buries its proboscis in the tissues and comes to rest in this position. 
During the search for favourable situations large numbers of the young 
grubs die, either through being unable to travel the necessary 'distance 
to find a suitable twig to feed upon, or owing to their inability to pierce 
the cortex and insert their proboscis to obtain nourishment. 
As soon as the larva has come to rest it commences to suck up the 
sap of the tree and exude a substance which, drying round it on contact 
with the air, gradually forms a cellular structure wliich is either circular 
or ovoid in shape. PI. II, figs. 1 h and 1 c, show transverse and longi- 
tudinal sections of lac cells. The former are the female incrustations 
and are larger than the latter, which are the males. Owing to the habit 
of the young grubs in swarming in large numbers together and fixing 
themselves to twigs in close adjuxtaposition, the cells, as they undergo 
enlargement, gradually coalesce and thus produce the well-knovui thick 
incrustation on the branches which is commonly kno^vn as lac {vide 
figs. 1, la). During the growth in size of the female incrustations or 
cells, which are the most numerous, structural changes are taking place 
