56 
THE LAMPYRIDiE OF BORNEO. 
But many females are apterous (wingless), or possess but 
rudiments of wings and elytra; in appearance they are 
like larvse, and are content to crawl slowly in grasses or 
bushes, principally in wet localities. Their light is not 
intermittent like that of the winged males, but continuous 
and very intense with certain species, and is only ex¬ 
tinguished when the insect returns to its place of con¬ 
cealment. 
The larvae, which live in grasses and under dead leaves 
in fresh, damp, and even marshy places, are also luminous. 
The luminous organ of these insects occupies principally 
the ventral surface of the two or three last abdominal 
segments; it consists of plates of pale white, or yellowish, 
or reddish colour, which remain glossy after the death of 
the insects, and even after they have been completely 
dried. 
The method of light emission as well as the intensity 
and colour of flashes are different for each species ; but as 
these important characteristics can only be observed during 
life, accurate notes are much desired. 
A large amount of scientific work has been done on the 
means by which the Lampyrids produce their light; many 
interesting facts have been secured ; but, as yet, nothing 
truly satisfactory is known regarding the precise nature of 
their luminosity. 
The females of Pyroccelia, Diaphanes, Lamprophoms, are 
wingless and larviform, and, as they do not resemble the 
males, one cannot tell to which species they belong. To 
be able to determine them with certainty it is necessary to 
find them in copulation, or, failing that, to find the males 
near them. This information, which is so necessary to 
any study of the beetles of this family, can only be made 
in those regions which the species inhabit, and I take this 
opportunity of making an urgent appeal to those in Borneo 
who are interested in entomology; for, from them alone can 
we obtain the necessary observations. 
In the evening at nightfall, if one walks in fresh and 
damp places, one will see shining on the grass, decaying 
vegetation, or on bushes, the light indicative of the 
female, and nearly always one will find by her side one or 
more males which will certainly be of the same species. 
Then one must take them carefully and place both sexes 
together in a small tube filled with alcohol; thus one will 
have authentically the two sexes of the same species. One 
should take care, however, not to place any males captured 
