10 Dr. & the Rev. 8. Graham Brade-Birks— 
Gazagnaire goes on to state that there may be exceptions 
of his rule, and quotes J. V. Audouin’s capture of luminous 
Geophilus electricus in August. He admits two hypotheses 
in such cases: either the reconciliation of the sexes has 
taken place earlier, owing to the occurrence of certain acci- 
dental conditions, local, atmospheric ; or the date given is 
the precise date of reconciliation of the sexes in those species, 
and, in that case, we find ourselves faced with a simple 
generic or specific difference in the date when the genital 
organs become functional, a difference of little importance 
which has been proved often enough in other groups. 
He thinks that if we accept only these two hypotheses, 
then the history of phosphorescent Geophilide as known in 
Gazagnaire’s time would not allow us to suppose that in these 
animals luminosity could go on under the same conditions 
as in certain other arthropods of the class Insecta—for 
example, in the Lampyres and Photophores,—nor that the 
egg, young, and adult, throughout their respective existences, 
rejoiced in the property of § giving light, as the insects just 
mentioned do in each of the Tife-stages referred to. 
Gazagnaire also adds some comparisons with the phos- 
phorescent Lumbricide. According to the evidence before 
him, worms found phosphorescent are provided with a well- 
developed clitellum, a fact indicating sexual maturity. This 
association of circumstances presents to his mind some 
important parallels to the case of luminous Chilopoda. 
We have seen a French contemporaneous account (5) of 
some researches of Dubois, to which Verhoeff (12) was 
evidently referring in the summary on luminosity to which 
we have already drawn attention, but Dubois evidently made 
several observations for which Verhoeff did not find a place 
in his account of the phenomenon. Dubois (5) stated that 
when one of his centipedes (Scolioplanes crassipes) was seized 
it discharged all the luminous substance it contained, but 
could be made luminous again some time later by mechani- 
cal stimulation or by raising the temperature. He confused 
the contents of the epithelial cells of the intestine with small 
granules (to which he attributed luminosity) in a discharge 
from the terminal part of the digestive tract. He speaks of 
these as the same characteristic birefringent granules, which 
he says are to be found in the luminous tissues of Pyro- 
phores and Lampyrids. He also states that the physio- 
logical process is, in its root-esséentials, the same in 
bs myriapods ” and Coleoptera, for, in both cases, the 
discharge of a cell sets free photogenic products. He adds 
