Notes on Myriapots. 5 
course, not yet been decided whether the fluid itself or light- 
bacteria cause the luminosity. Certainly this much is 
established, that forms which have been taken luminescent 
like Scolioplanes crassipes only exhibit this property excep- 
tionally. The luminescence is not of long duration and, 
according to Duboscegq, is particularly noticeable in spring.” 
In the closing section of the same work, Verhoeff (12) 
deals with the subject of luminosity itself. He 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 :— 
Scolioplanes crassipes (C. li. Koch). 
Geophilus electricus (L.). 
G. longicornis, Leach. 
Orphneus brevitabiatus (Newport). 
Stigmatogaster subterraneus (Shaw). 
Orya barbarica (Gervais). 
Verhoeff, whose remarks we had better consider briefly 
here, then reviews some of the observations and suggestions 
of the earlier workers and adds a few of his own, One 
opinion of Dubois, that the luminous substance is to be found 
in the epithelial cells of the alimentary canal, and that of 
Macé, that it occurs in anal and coxo-pleural glands, he 
negatives. He mentions that Gazagnaire, who, he says, 
pointed out the suitability 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- 
nous in Orya and Scolioplanes, and, since all the specimens 
of Orya investigated by Gazagnaire exhibited luminosity, 
Verhoeff concludes that either all Orya are luminous or that, 
at least, luminosity occurs in all individuals at some special 
time. Verhoeff has made some investigations himself 
regarding Scolioplanes, and he considers it proved that these 
are by no means always luminous. Verhoeff had never 
observed Geophilus longicornis luminous... He speaks of 
Dubois’ experience of Scolioplanes crassipes in fields near 
Heidelberg. Luminous material was transferred to the 
fingers and the light emitted was so bright that printing or 
figures could be made out 10 paces away; the luminous 
tracks left behind by Scolioplanes consisted of little irregular 
masses covered by a sticky substance. Dubois’ statement 
that the luminous material was only discharged from the 
