26 Dr. & the Rev. 8S. Graham Brade-Birks— 
misleading factors: Forel (9) has devoted some space to 
them in the case of insects. 
(1.) Photodermatic sensations. 
When we speak of these Geophilomorphs as blind animals, 
we must remember that though it is true that they have no 
eyes, no specialised organs of sight, they may be able to 
appreciate light by a general absorption of its waves through 
the surface of the body. Pigment-cells, which we have 
found abundantly present in the connective tissue close to 
the chitin of both dorsal and ventral surfaces of the trunk 
in luminous specimens of G. carpophagus, might play an 
important part in such an absorption. 
(i1.) Smell. 
Again, as we speak of the odour of the luminous fluid in 
G. carpophagus, we must not forget that the odour, as we 
perceive it, may have no counterpart in the experience of 
the animal producing it. 
Sexual Significance. 
Young and adult, male and female alike, exhibit lumi- 
nosity, aud we have already stated (2) that it seems unlikely 
that the character is a sexual one. In Kent luminous 
specimens of G. carpophayus have been taken in December, 
January, February, and April, and in Lancashire we have 
collected specimens which were afterwards luminous upon 
stimulation from April this year (1919), fairly frequently up 
to the month of writing this paper (September). Gazagnaire 
(10) based his theory of the sexual significance of this phe- 
nomenon upon records which only covered a limited period 
of the year. 
Protection. 
Both the ight and the odour may be protective against 
enemies. 
Accidental Property. 
We must not lose sight of the fact that luminosity may 
be an entirely neutral factor in the economy of this animal, 
and that the product of the “‘ white glands’ may be entirely 
accidentally photogenic. 
