-~ 
[ 83 ] 
X. On the Glow-worm. By Mr. W. Rocerson, Jun. 
Pocklington, June 20, 1821. 
Sa, — Tu E following remarks on that curious insect called the 
Glow-worm, are founded on my own experience.—If you think 
they will be entertaining or useful to any of your readers, they 
are at your service. ; 
The glow worm is an insect of the beetle kind:—the female 
deposits her eggs in the months of June or July, among moss, 
grass, &c.: these eggs are of a yellow colour, and emit light. 
After remaining about five or six weeks, the larve break the 
shells and make their appearance: at first they appear white, 
and are very small; but they soon increase in size, and their co- 
lour changes to a dark brown or nearly black colour. The body 
of the larva is formed of eleven rings ; it has six feet, and two 
rows of reddish spots down the vack. It emits light in the dark ; 
this light arises from the last ring of its body under the tail, and 
appears like two brilliant spots when examined attentively. 
The larve are seen creeping about and shining during the fine 
nights in autumn, and the light they emit is to direct them to 
their food: they feed on small snails, the careases of insects, &c. 
They frequently cast off their skins. 
After the expiration of about one year and nine months from 
their birth, they arrive at their perfect size—they then cease to 
eat, cast off their skin, and assume another appearance: the form 
of the perfect insect may be diseovered through a thin skin that 
covers them, After-remaining in this state two or three weeks 
(scarcely ever moving) they throw off their last skin, and arrive 
at perfection. The male then appears a perfect beetle, having 
wings, and coverstothesame. ‘The female, on the contrary, has 
neither wings nor wing cases: she is larger than the male, and 
of a lighter colour. It is the female that principally shines in 
the perfect state: her light is far superior to that emitted by the 
larva, and arises from the three last rings of the body on the lower 
side. The reason why the female shines, I am assured from re- 
peated experiences which I have made, is to allure the male to 
her company. 
Here we behold the wonderful wisdom of the great Creator; she, 
being void of wings, therefore incapable of flying through liquid air 
to seek her mate, is provided with a beautiful lamp which answers 
her purpose as well. After the female has been impregnated by 
the male, she deposits her eggs, and dies. The male dies also. 
Those who wish to investigate this curious insect, may keep 
them in glass jars, among damp moss, and feed the larvae with 
snails cut into pieces. J have kept glow-worms for years in glasses, 
and have traced them through all the changes of their lives from 
their exclusion from the egg to their death. 
To the Editor of the Phil, Mag. W. Rocerson, Jun. 
