among certain j^nnelides and Ophiurid(B. 107 



Under these different manipulations, my annelide was broken into a 

 great number of fragments. All of tliera, however, more or less main- 

 tained their luminous properties ; and all that was required to repro- 

 duce the phosphorescence was to move them with a pin. With them, 

 as with the halves which at first were the objects of my examination, 

 muscular contraction and the appearance of light were phenomena 

 which appeared thoroughly connected with one another. 



After more than an hour's observation, I compressed the remaining 

 fragments between the plates of my instrument, so as to crush them. 

 During this operation, there was not the slightest trace of liglit ; but 

 when I relaxed the amount of the pressure, and at the instant that the 

 two glasses rapidly separated by the action of the spring, it afresh pre- 

 sented itself. This phenomenon was noticed several times, and under 

 sufficiently high powers. I still recognised that the parts which dis- 

 played it were always and solely the muscular organs, which, lengthened 

 and flattened by the pressure, regained their natural state upon its re- 

 moval. 



The observations mentioned above were made at Chausey in the year 

 1841. Occupied with other pursuits, I could not at that time follow 

 them up ; I have since, however, completed tliem, at St Waast-la- 

 Hougue, during the year 1842. 



The annelides of this locality exhibited nothing that was new to me ; 

 but I noticed, in some of the microscopic species, the facts I am about 

 to detail. I ought here to remark, in general, that the phenomena did 

 not on this occasion exhibit themselves so conspicuously; but whether 

 this was owing to the character of the season, or to the phosphorescence 

 being weak in the species I captured, I cannot say. Nevertheless, I 

 did very clearly observe them in a small polynce 3-4 lines in length. 

 With the naked ej'e, I could recognise that the creature was not lu- 

 minous throughout its whole extent, and that the phosphorescence was 

 confined to certain points upon the sides of the body. Under a magni- 

 fying power of 3 diameters, I perceived, as I had done before, every 

 one of these points decompose itself into the appearance of a star, and 

 upon the muscles I could distinguish some of the isolated scintillations, 

 which together formed the radiation of the star. 



The minute greyish ophiura displayed appearances altogether ana- 

 logous. Often, the instant they were touched, they threw their five arms 

 into action, and sparkled from one extremity to the other. The colour 

 they exhibited was of a yellowish green. Their body remained quite 

 obscure. With the naked eye, it clearly appeared that the light upon 

 the arms was not uniform, but that it issued forth from those spots which 

 corresponded with the joints. In watching them with a suitable micro- 

 scope, and with the necessary precautions, it was apparent that these 

 points were composed — not of a star as in the annelides, but of parallel 

 luminous strise. Altogether they formed a kind of phosphorescent ring 

 round the joint. 



