
500 THE INSECT WORLD. 
soft, which very soon hardens, and becomes of a bright tawny 
colour ; it 1s called the pseudo-nymph (Fig. 545). It goes through 
the winter in this state. In the spring comes forth a third larva 
(Fig. 546), resembling the second. This one does not eat, and 
moults after a time. It very soon changes into an ordinary 
pupa (Fig. 547), of a yellowish-white, from which comes forth the 
adult Seéaris, which lives only a few days, to ensure the propaga- 
tion of its species, as is observed in the case of the Ephemere. 
The larve of the Sttaris had for a long time been remarked 
clinging on to the hairs of the Anthophoras; but they were always 
taken for Acari, and they had been described as such. 
The Lampyrid@ have the elytra weak and soft, like the insects 
of the preceding tribe. In their perfect state they frequent 
flowers. The larvee are carnivorous, attacking other insects or 
worms. It is to this group that the Lampyris noctiluca, or glow- 
worm, which one sees shining during summer nights on grass 
and bushes, belongs. It has the power of making this natural 
torch shine or disappear at will, which is, by-the-bye, a property 
common to all phosphorescent animals. 
The luminous properties with which these insects are endowed 
have for their object to reveal their presence to the opposite sex, 
for the females alone possess these properties. In the same way 
as sounds or odours exhaling from some insects attract the one 
towards the other sex, so with the Lampyris a phosphorescent 
light shows the females to the males. The seat of the phos- 
phorescent substance varies according to the species. It exists 
generally under the three last rings of the abdomen, and the light 
is produced by the slow combustion of a peculiar secretion. It 
has been stated that it is evolved quickly when the animal con- 
tracts its muscles, either spontaneously or under the influence of 
artificial excitement. Some chemical experiments have been made 
to ascertain the nature or the composition of the humour which 
produces this strange effect; but, up to this moment, they have 
only enabled us to discover that the luminous action is more 
powerful in oxygen, and wanting in inert gases. In the most 
common species, the Lampyris noctiluca, or Glow-worm, the phos- 
phorescence is of a greenish tint; it assumes at certain moments 
the brightness of white-hot coal. 

