miscellaneous. 477 



muscles presented a protound alteration, which explained the en- 

 feebling of the animal's movements. 



To study the Eacteria more completely I collected a drop of blood 

 from the Talkrus aiid added to it a drop of gentian-violet. Thus 

 treated the Eaeterian was brightly coloured. It presents the form 

 of a DiplohacteritDii measuring about 2 yu ; each of the geminate 

 joints is less than 1 ju. There are also chaplets of three or four 

 joints, rarely more, and here and there a few isolated bacilli, a little 

 longer (3-5 jx). 



The phosphorescent disease being manifestly of an infectious 

 nature, I tried inoculations upon TaJitri and Orchestiw (0. liUorea, 

 Mont.). Eor this purpose I cut off two more legs of the luminous 

 TalUrus. Each of these was torn up separately in blood of Talitrus 

 and of Orclustia ; then with, a sterilized needle I pricked the Talitri 

 and the Orclustkn on the sides of the body, taking care not to wound 

 the liver or touch the dorsal vessel, in order to avoid a too abundant 

 haemorrhage. I then applied a drop of virus to the wounded places, 

 and the inoculated animals were enclosed in glasses furnished with 

 a thin layer of sand, and covered over and placed in the cellar of the 

 laboratory at the temperature of SQ^-Gi"^ E. 



The result exceeded my expectations. Of the Talitri inoculated 

 on the Gth September six began to shine on the 8th and appeared 

 on the evening of the Dth as brilliant as the first luminous Talitrus. 

 Out of a dozen Orchestice inoculated the same day three became 

 phosphorescent on the 9th and were resplendent on the 10th. I 

 have since continued the inoculations, operating about every two 

 days ; and I possess at preseut Talitri of the sixth luminous genera- 

 tion and Orchesticp of the fourth generation. The action of the 

 microbe does not seem to diminish at all, and in the evening the 

 cellar of the laboratory presents a fair}- asjject, which is the admira- 

 tion of the bathers staying at Wimereux. 



The liacteria is not modified by passing into the OrcJiestia ; Talitri 

 inoculated with virus taken from Orchestiw of the third generation 

 behaved as if they had been infected by the blood of other Talitri. 



The disease follows a very regular course. At first one sees only 

 a luminous point at the place of the puncture. After the lapse of 

 from forty-eight to sixty hours the whole animal is phosphorescent, 

 but with a white light which has little external difi^usion. At this 

 time the Talitrus still shows great activity. After the third or 

 fourth day the phosphorescence becomes brilliant and of a fine 

 greenish tint and the animal throws out a bright light around it. 

 It may be perceived at a distance of 10 metres, and two Talitri 

 suffice to enable one to see the time by a watch as in full daylight. 

 At this phase of the malady the Talitms progresses more slowly ; it 

 can still issue from its burrow, which it illuminates, and return 

 there if disturbed. The period of this state may last from three to 

 six days ; then comes a period of immobility, during which the 

 phosphorescence retains all its brilliancy. Lastly, in three or four 

 more days the animal dies ; the body remains phosphorescent for 

 some hours and then acquires a very characteristic brown tint. 

 Frequently the point of inoculation is suri'ounded by a small blackish 

 circle. Lowering of the temperature seems to prolong the life of 

 the animal: Talitri inoculated on the 9th September and kept at a 

 temperature of oO' -.37° E. were still living on the 22nd September, 



