Notes on Myriapohi. 5 



course, not yet been decided whetlier the fluid itself or liglit- 

 baeteria cause the biniinosity. Certainly tliis much is 

 estaljlished, that forms whicli have l)een taken luminescent 

 like ScoliuplcDies crasKipes only exhibit this property excep- 

 tionally. The luminescence is not of long duration and, 

 according to Duboscq, is particularly noticeable in spring/' 

 In the closing section of the same work, Verhoelf (i?.) 

 deals with the subject of luminosity itself, lie mentions 

 the following species as luminous forms, with a reservation 

 concerning the certainty of correct diagnosis of the species 

 of Geophilus included in the list : — 



Scoliophines crassipes (C. L. Kocli). 



Geophilus electricus (L.)- 



G. loiiyicornis^ Loach. 



Orpknceus brevilabiatus (Newport). 



Si iyinatoy aster suhterraneus (Shaw). 



Orya barbaricu (Gicrvais). 



YerhoefF, whose remarks we had better consider briefly 

 licre, then reviews some of the observations and susfuestions 

 of the earlier workers and adds a iew of his ovviu One 

 opinion of Dubois, that the luminous substance is to be found 

 in the epithelial cells of the alimentary canal, and that of 

 Mace, that it occurs in anal and coxo-plcural glaiuls, he 

 negatives. He mentions that Gazaguaire, who, he says, 

 pointed out the suital)ility of Orya barbarica for an enquiry 

 into light-production, saw on the sternite and pro- and meta^ 

 coxa a viscous yellowish mass coming out of the glands and 

 spreading over this region with the emission of a blue-green 

 light. Pressure increased the flow. Next he states that 

 Gazagnaire and Dubois show that both the sexes are lumi- 

 - n(jus in Orya and Sco/iopluues, and, since all the specimens 

 of Orya investigated l)y Gazagnaire exhibited luminosity, 

 A'^erhoetf concludes that either all On/a are luminous or that, 

 at least, luminosity occurs in all individuals at some special 

 time. Verhoeff has made some investigations himself 

 regarding Sco/ioj/laues, and he considers it pi'oved that these 

 are by no means always luminous. Verhoelf had never 

 observed Geophilus lunyicomis luminous. He speaks of 

 Dubois' experience of Scotioplanes crassipes in fields near 

 Heidelberg. Luminous nuiterial was translerrcd to the 

 fingers and the light emitted was so bright that printing or 

 iigures could be maile out 10 paces away; the luminous 

 tracks left behind by Scolioplanes consisted of little iVregular 

 masses eoveied by a sticky substance. Dubois' statement 

 that the huninous material was only discharged fi'om the 



