Hudson and Skuse. — On tJic K.Z. Gloincorm. 45 



luminous when in contact with tlie oxygen in the air-tubes. 

 Larvas cease to shine on very cold nights, in the day-time, and 

 in a room which is artificiaUy lighted. 



During my observations in 1886 one of the larvas disap- 

 peared, and I naturally assumed that it had buried itself in 

 the earth, and was undergoing its transformation into the 

 pupa state. This was apparently confirmed by the emergence, 

 in about a month's time, of a fly which was afterwards identi- 

 fied by Baron Osten-Sacken as Trimicra pilipes, whose larva 

 is well known, and has nothing to do with the present insect. 

 It is most unfortunate that a larva of this Trimicra should 

 have got into the breeding-cage without my knowing it, and 

 thus deceived me. 



Further investigations were instituted at the end of 1886, 

 when I discovered a luminous pupa suspended in one of the 

 webs in the manner represented at fig. 2, which I have since 

 several times reared from the glowworm, and which is con- 

 sequently the real pupa. It is a curious animal, furnished 

 with a large process on the back of the thorax, which is 

 attached to the web, and holds the pupa suspended in the 

 middle of the niche previously inhabited by the larva. The 

 light is emitted from the posterior segment of the pupa, but is 

 much fainter than in the larva, and a distinct organ is not 

 apparent. It is frequently altogether suppressed for days to- 

 gether. This pupa died in a few days, and all the larvse then 

 under observation also died. 



Larvae were again procured in August, 1888, but this time 

 I did not succeed in getting any of them as far as the pupa 

 stage. I should mention that the larvae are only to be ob- 

 tained by walking up the bed of the stream in the big gully of 

 the Botaui-^al Gardeiis at night, with a bull's-eye lantern. A 

 piece of thin stick is raj)idly introduced behind the larva as 

 soon as it is detected, which always adheres to it, and is thus 

 taken away, web and all, and carried home in a tin box with 

 damp moss, c'tc. 



On the 1st September, 1888, I obtained another supply of 

 larvae, placing them this time in a large bell-glass with stones 

 and ferns, the bottom of the glass having about lin. of water 

 in it. Tliis I conceived would closely resemble their natural 

 habitat. During all my expeditions I always examined a 

 great number of the webs, and could never find any remains 

 of insects entangled. I also noticed that the largest larvae 

 were always concealed in the deepest niches in the bank, and 

 frequently behind large cobwebs, where they would stand a 

 poor chance of capturing insects. I also think that there 

 must be a very great mortality among the larvae, judging from 

 the number of minute ones always observed, in natural con- 

 ditions, compared with large ones. On the 21st December I 



