igiS.] C. A. Paiva : The Indian Glow-worm. 27 



got rid of. It seemed greatly affected when any light shone 011 

 it. On the 25th morning the ventral plates still appeared to be 

 uncast. Something seemed to have gone wrong with this creature 

 as it lay on its back till the 28th, glowing very gently when 

 exposed to view, either during the day or at night, but its moult 

 was not completed. On the 29th it had discoloured altogether 

 and had no resemblance, as far as colouration was concerned, to 

 the pupa of the Angul insect. Its glow even began to be very 

 irregular and faint. It was still limp and I took it out of its 

 " dug-out." Several pieces of its larval skin still adhered to its 

 ventral surface, especially over the stigmata. This probably caused 

 asphyxia and the creature eventually died. I cannot assign any 

 other reason for its death. It had lived under the same conditions 

 as the larva from Angul, in fact it had been so well fed that it 

 grew to an enormous size and prior to its leaving off eating it 

 looked almost cylindrical. From the very beginnmg this larva 

 seemed to have had some difficulty in ridding itself of its skin 

 when moulting. At its last but one moult its larval skin was cast 

 piece-meal, whereas in the case of the Angul specimen the larval 

 and pupal skins were cast intact. 



A point worthy of note is that I had never observed these 

 larvae to glow during the day if undisturbed, though kept, for 

 the most part, in a semi-dark room. The admission of strong 

 sunlight did not even affect them, but any sound, however 

 slight, caused them to glow immediately. After dusk the larva, 

 when in the "dug-out," glowed continuously all night and the 

 rays of light passing through the opening of the *' dug-out" 

 diverged to a great extent, reminding one of the rays of a search- 

 light, for any object coming within these rays was enormously 

 magnified. With regard to the glowing of the larva there is a 

 difference in the use of the luminous organ when the creature is in 

 the open and when it is in a hole. In the former condition it 

 glows with both its luminous organs if it apprehends any danger, 

 but in the latter state it only glows with that part which is upper- 

 most and in a line with the opening of the " dug-out," the light 

 being sufficiently strong to be seen at a great distance. The 

 terminal sucker has been said to serve as an organ of locomotion, 

 an organ of respiration, and an organ accessory to feeding. Of 

 the first two there may be no doubt, but I have never seen a larva 

 smear its head with any secretion preparatory to attacking a snail. 

 Mr. C. J. Gahan says, "It is well known that Lampyrid larvae 

 use the terminal sucker to clean their heads and limbs from, the 

 slime of the snail after having fed on the latter. " This, which 

 seems to be its chief use, I have explained fully on page 22. The 

 luminous organ, as far as I have been able to observe, is used 

 chiefly as a means of defence in the larva and as a means to 

 attract the males in the adult female These larvae belong to that 

 group of Malacoderms in which the female is larviform and the 

 male is winged. The light emitted by these insects, both males and 

 females^ is not intermittent, but a bright steady glow. In that 



