152 Miscellaneous. 



oblong in form, with the shoulders almost rectangular; their 

 surface bears numerous large, pale red nodules, with smaller 

 asperities and irregularly arranged small depressions between 

 them. The legs are obscure red, the tarsi blackish red. 



Cambridge, 

 November 1890. 



MISCELLANEOUS. 



Phosphorescent Centipedes. 



That there are luminous Myriopods has been known for many years, 

 as also the fact that they occur only among the family Geophilidae of 

 the Chilopod Myriopoda. Both sexes are luminous, sometimes quite 

 intensely so, and the luminosity spreads out over the whole ventral 

 surface of the animal. If one of these Geophilids is taken up the 

 luminous matter communicates to the hand of the observer or to 

 anything else with which the specimen comes into contact. 



There is considerable dispute regarding the origin of this phospho- 

 rescent matter. Accoi'ding to Dr. 11. Dubois it is contained in the 

 epithelial cell of the digestive tube, and the emission of the light 

 depends on the moulting of the digestive tube. Mr. Mace, on the 

 contrary, contends that the luminous matter is a glandular excre- 

 tion, and that these glands (glandes preanales) are situated on the 

 last two segments of the animal. Mr. J. Gazagnaire has satisfied 

 himself that the luminous matter is secreted from glands situated on 

 the sternal and episternal plates. Upon pressure these glands secrete 

 a yellowish viscous substance, having a peculiar odour, and which is 

 highly phosphorescent. 



In a more recent article (Mem. do la Soc Zool. de France, t. iii. 

 1890, pp. 136-146) Mr. Gazagnaire reviews all previous observations 

 on luminous Geophilids, and finds that, so far as the European fauna 

 is concerned, luminous specimens were found only between the end 

 of September and beginning of November. The luminosity appears, 

 therefore, only at a certain epoch in the life-history of these Myrio- 

 pods. Further, in all more carefully recorded cases luminous speci- 

 mens were never ftmnd singly, but always in pairs or in companies 

 of three or more specimens. The few and fragmentary observations 

 that have hitherto been made on the mode of reproduction in these 

 animals seem to prove that the fecundation of the female takes place 

 in autumn, or just at the time when the luminous specimens are 

 found ; and Mr. Gazagnaire is thus fully justified in connecting the 

 appearance of luminosity with the excitement caused by sexual 

 instinct. 



In Algiers, Mr. Gazagnaire observed luminous specimens of Oriju 

 barbaricd in the month of April ; and he concludes that in other 

 countries and in consequence of altered climatic conditions the period 

 of luminosity probably differs from that observed in Europe. — Insect 

 Life, vol. iii. no. 4, p. 173. 



