JS^otes on ^fyriapoda. 



27 



If such be tlie case, the protohicifh'in may be of service to 

 tlie animal as an efficient constituent of the complex Huid 

 produced l)y the niiugliuu; of the secretions of the glands of 

 the sternal and episterual regions. This complex fluid may 

 have one or a number of uses, and there is a multii)licity of 

 possibilities to choose from. It may act as a cement for 

 iiest-building, as a lubricant, or as a protection from the 

 attacks of micro-organisms living in the soil ; and liere we 

 may note that the films of excretion we exauiincd critically 

 contained remarkably few micro-organisms, and the sternite 

 is evidently kept very clean in a healthy luminous G. car- 

 j)nph(igus. Or, again, the fluid may act as a directional guide, 

 enabling the animal to retriice its steps by perception of a 

 track of the excretion made on the outward journey. Or, to 

 take a last example of the possil)ilities, it may, owing to its 

 ])r()|-.erty of drying ra{)idly, be of service to the animal in 

 liel[)ing to free the body from excessive surface-moisture 

 iu damp or wet weather. 



Sammarij. 



Briefly to summarise the most important results of our 

 cncjuiry: np to the piesent, we may say that in Geophilus 

 CAUPOPHAGUS, protoluciferin, here essential for light-produc- 

 tion, is secreted by the white glands which lie immediately 

 dorsal to the sternal and episternal plates. Upon the 

 application of stimuli to the central nervous system, mus- 

 cular contraction takes })lace and the pj-utolucij'erin glands 

 discharge their contents to the exterior into contact with 

 the excretions of other glands o]jening upon the ventral 

 surface. The fluid thus excreted is viscous, colourless, with 

 an odour sui generis, acid in reaction, and exhibiting the 

 micro-staining properties of a bacteria-free acid ])rotcin. 

 It contains within itself all the essentials for the chemical 

 action which results in the production of light and the 

 formation of crvstals. 



Future work lies in the further elucidation of the chemical 

 aitd piiysical aspects of the subject, and in the search for the 

 real explanation of the economic value of the phenomenon. 



7 '/tanks. 



Mention has been made in the course of our paper to the 

 h(;lp given to us by Professor Newbery and Mr. C. \V . Ashton. 

 We are also indebted to Mr. Henry Stephen, M.Sc, Lec- 

 tuier in Chemistry in the Victoria Ui.iversity of Manchester, 



