Notes on Mf/n'apoda. 13 



luminous centipedes (see also PI. I. fig. 6 and explanation 

 of same). This book gives a very useful summary of many 

 interesting points relating to the subject. All who have a 

 comprehensive interest in the problems of the production 

 of light by animals will find in the papers of a modern 

 writer. Prof. Dahlgren (4), very valuable summaries of many 

 of the results of a long line of observers. Prof. Dahlgren 

 touches upon luminosity in the plant-world, and surveys its 

 production in many of the systematic subdivisions of the 

 animal kingdom. But from a consideration of that section 

 of Prof. Dahlgren^s third paper (4 c), which deals with the 

 power of ligliting in the animals with which our present 

 study is especially concerned, we realise at once how much the 

 problems met ^Yith here have baffled earlier investigators. 



II. Our recent Investigations. 



« 



Int7'oduction. 



On the 2.2nd of April, 1919, we were walking together on 

 hills near our own home in Darwen, Lancashire, when we 

 casually collected several Geophilidsealiveand took them home. 

 They proved to be Geophilus carpophagus. Leach (fig. 1), and 

 were luminous when stimulated in the dark. With this 

 discovery a new era begins for us in our study of luminous 

 centipedes. We had already experimented with some lumi- 

 nous specimens sent to us alive by members of the Dartford 

 iNaturalists' Field Club, and had learned from their hints 

 and our own experience that it was possible to keep these 

 animals alive in jars if a good supply of fresh damp soil be 

 provided for them; moreover, the power to luminesce is 

 retained in captivity over a long period. But with a wealth 

 of material at our doors we were able to carry on our 

 research with much greater confidence. 



In Norfolk, during a holiday in j\lay and June, 1919, Ave 

 obtained one specimen of G. carpophaf/us between the trunk 

 and bark of felled timber in ]Mr, Witton's wood-vard, 

 Heacham. This was luminous upon stimulation. The 

 Misses Cox of Heacham and Mr. Witton were familiar with 

 the occurrence of luminous centipedes locally, where they 

 seem to be known as " glow-worms." 



Subsequenily, at a joint tiekl-meeting of the Lancashire 

 and Cheshire Fauna Committee and the Burnley Natural 

 History Society on 26 July, 1919, Mr. W. G. Clutten, one 

 of the Vice-Picsidents of the latter organization, took one 

 specimen of G. cuipopli(i<ius at Extwistle, near Burnley, and 



