10 Dr. & the Rev. S. Graliam Brade-Biiks— 



Gazagnaire {roes on to state tliat there may be exceptions 

 of liis rule, and quotes J. V. Audouin's capture of luminous 

 Geophilus clectrictis in August. He admits two hypotheses 

 in such cases : either the reconciliation of tlie sexes has 

 taken phice earlier, owing to the occurrence of certain acci- 

 dental conditions, local, atmospheric ; or the date given is 

 the precise date of recouciliatiou of the sexes in tjjose 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 ditlerence 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 phos[)horescent Gcophilidfe 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 — fur 

 example, in the Lampyres and Photophores, — nor that the 

 egg, young, and adult, throughout their res])ectivc existences, 

 rejoiced in the property of giving light, as the insects just 

 mentioned do in each of the life-stages referred to. 



Gazagnaire also adds some comparisons with the phos- 

 phorescent Lumbricidic. According to the evidence before 

 liim, worms found phosphorescent are i)rovi(lod with a wcU- 

 developetl clitellum,.a fact indicating sexual maturity. This 

 association of circumstances presents to his mind some 

 important parallels to the case of luminous Chilopoda. 



\\'e 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 alreadv drawn attention, but Dubois evidentlv made 

 several observations for which \ erhoefl' did not find a ])lace 

 in his account of the phenomenon. Dul)ois (5) stated that 

 when one of his cei\i\\}ci\c?,{Scolio planes crassipes) was seized 

 it discharged all the luminous substance it contained, but 

 could be made luminous again some time later bv mechani- 

 cal stimulation or by raising the temperature. He confused 

 tlie contents of the epithelial cells of the intestine with small 

 granules (to which he attributed luminosity) in a discliai-ge 

 fr(jm the ti-rminal part of the digestive tract. He speaks of 

 these as the same eliaraeteristie birefringent gi'anules, which 

 lie says are to be found in the luminous tissues of Pyro- 

 phores and Ijampyrids. He also states that the physio- 

 logical process is, in its root-essentials, the same in 

 " myriapods " and Coleoptera, for, in both cases, the 

 discharge of a cell sets free photogenic products. He adds 



