204 Transactions of the Royal Society of South Africa. 
of luminous fungi in the food of the animal. The presence of luminous bac- 
teria or fungi seems a most probable explanation, and appears to be generally 
accepted, but, maybe, it is just because of this plausibility that the pheno- 
menon has not been adequately investigated. 
There does not appear to be any record of such an occurrence in S. Africa, 
and yet it does not seem to be uncommon, for several correspondents have 
assured me that luminous " worms " have been observed in up-country dis- 
tricts. In some of these cases it is possible that the common glow-worms or 
centipedes may have been mistaken for worms. More convincing evidence 
has been obtained, however, nearer Cape Town. Mr. MacManus has, he 
informs me, frequently seen earthworms on damp nights crawling up on the 
verandah of his house, near the foot of Signal Hill, leaving a trail of luminous 
substance ; on a dark, wet night at Salt E-iver, a patch of luminous material 
was observed, which was given out by an earthworm ; a collector of material 
for the Zoological Department of the S. African College has frequently seen 
luminous worms at Maitland, and my friend, Dr. Purcell, informs me of an 
interesting case near Hermanns on the south coast. His attention was first 
attracted by observing the phosphorescence on a number of small toads in 
the grass after rain. Luminous fragments of earthworms were found on 
the spots occupied by the toads. Dr. Purcell was not sure that the toads 
had partly eaten the worms, but he attributed their luminosity to contact 
with the worms. The toads, on crawling away, left a luminous trail behind 
them ; he also informs me of another instance, in which he observed luminous 
patches on a spider, found in the grounds of the South African Museum. 
These patches were readily brushed off, and were believed to have been 
caused by contact with some luminous animal, probably a worm. 
That luminous earthworms are widely distributed in this country is 
rendered probable by an observation of Mr. E. J. O'Connor, who informs 
me that he has often seen them in damp weather at Limbe in the Shire 
highlands of Nyasaland. 
The occasion for these inquiries was the finding of several examples of 
a species of earthworm (apparently a species of Chilota), which certainly did 
produce a very striking display of light. The first specimen found was on 
July 19th, 1917, after an exceptionally heavy rain. It was found at dusk 
on a footpath through the pine- woods on the slopes of Table Mountain. The 
light given off was conspicuous, and could not have been overlooked by the 
most casual observer. A few yards further on another specimen was 
observed. In the first case there were patches of a luminous substance a 
few inches from each other, as observed in the case mentioned by Giard. In 
the second case these were closer together, and within an area which could 
be covered by the palm of the hand. The general appearance was not unlike 
that shown in Fig. 1, which was obtained by placing a worm on a photo- 
graphic plate in the dark. The irritation of the dry plate caused the animal 
