462 



NATURE 



[March 16, 1893 



number occur amongst Rotatoria, but additions are also 

 made to the Rhizopods, Heliosoa, and Infusoria. No new 

 forms appear to have been found amongst the Crustacea, 

 mollusca, or fishes. 



A third paper deals with the distribution and special 

 natural history of the forms met with, and with the com- 

 parison of the plankton at different seasons. 



There are no foot-notes through the number, but all 

 references to literature are formed into a numbered table 

 at the end. The plate, which is one of Klinkhardt's, of 

 Leipzig, shows a number of the new forms discovered. 



The investigations are almost entirely on the minute 

 floating organisms, as must necessarily be the case at 

 this date with all freshwater work not connected directly 

 with pisciculture. 



The British Journal Photographic Almanac for 1893. 

 Edited by J. Traill Taylor. (London : Henry Green- 

 wood, and Co., 1893.) 

 This annual volume contains, as usual, a vast amount 

 of useful information gathered from workers in all the 

 various applications of photography. After a brief sum- 

 mary, in which the editor refers to some of the chief 

 advances made in the science of photography during the 

 past year, mentioning, for instance, Mr. Dallmeyer's 

 telephotographic lens, Mr. Willis's improvement in the 

 p'atinotype process, &c., he devotes a few pages to " some 

 photographic methods of book illustration." Then come 

 short contributions in which everyonehas something special 

 to say, whether it relates to a new mounting medium, a per- 

 manent toning bath, or pinhole pictures, &c. They are far 

 too numerous to mention individually, but will be found 

 most interesting reading. " Epitome of Progress" is the 

 title of a series of notes by Mr. Traill Taylor, in which 

 he refers briefly, and in some cases at length, to new 

 methods, remedies, &c., and instruments used in the 

 practice of the art. The formulae and tables are as 

 numerous as ever, while all the qther information, such 

 as lists of photographic societies, &c., have been brought 

 up to date. The volume is copiously illustrated. 



Studies in Corsica. By John Warren Barry, M.A. 



(London : Sampson Low, Marston, and Co., 1893.) 

 Mr. Barry has twice visited Corsica, the first visit being 

 of less than five months' duration, while the second 

 extended from September 1882 to February 1885. He 

 has thus had ample opportunities for the study both 

 of the island and of its people, and in the present 

 volume he sums up his impressions very brightly and 

 pleasantly. Most readers will probably like best the 

 chapters on life at Ajaccio, but they will also find much 

 to interest them in what the author has to say about the 

 Bush of Corsica and of the Mediterranean region. 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications. ^ 



Luminous Earthworms. 



I HAVE recently received from a correspondent a statement 

 which is sufficiently valuable to crave public attention. It opens 

 up withal a very fascinating field of investigation, and one 

 which, though it has by no means been altogether neglected by 

 foretime naturalists, is as yet far from being fully understood. 



Writing from Richmond, Surrey, the Rev. Alfred Geden, 

 M.A., says : — " I have just heard of a phenomenon in the worm 

 world which is new to me . . . My sister declares that one day 

 last summer, in a village on the Thames, she saw a ' phos- 

 phorescent worm,' and describes the creature as about one and 

 a half inches long, worm-like in all respects. My sister is sure 



it was not an ordinary glow-worm, with which she is perfectly 

 familiar ; and, moreover, she called the attention of a cousin 

 to the creature at the time, who corroborates her account. Are 

 there worms in England capable of emitting light besides the 

 glow-worm ? If so, are they at all common?" 



In reply to a series of questions, I was able to elicit these 

 further particulars : — " It was in a garden in the village of Long 

 Wittenham, near Didcot, on a dark evening in the latter part of 

 September last [1892], or the beginning of October. My sister's 

 attention was attracted by the light on the ground, and she 

 picked the worm up. While she cannot positively assert that 

 she saw it in motion on the ground, it certainly wriggled in her 

 hand. For a few seconds also after putting it down her fingers 

 remained phosphorescent." 



The notice of the public, so far as I have been able to ascer- 

 tain, was first directed to this phenomenon among earthworms 

 by Grimm in 1670, but scientific observation, as we now under- 

 stand it, was then scarcely known. A century elapsed before 

 any further record was made in the periodicals of Europe which 

 I have consulted, then came a paper by Flaugergues in 1 781. 

 This article, which appeared in Lichtenberg's magazine, was 

 written in German. In 1873 Cohn's observations on the same 

 subject were published in the well-known Zeitschrijt fiir Wis- 

 sensch. Zool., while numerous recent writers have further con- 

 tributed to our knowledge, especially in relation to the Con- 

 tinental species. 



Thus in 1872 an article appeared in the French Annals of 

 Natural Science, by Panceri, entitled " Studies in the Phos- 

 phorescence of Marine Animals," in which he states that the 

 luminosity observed in the case of certain (earth) worms is due 

 to a secretion from the girdle, where special glands exist, and 

 that by the evolution of light there was no perceptible raising of 

 the temperature. In this respect, therefore, the earthworm's 

 glow corresponds with that emitted by the firefly, Noctiluca, 

 and glow-worm. One investigator at least has tested the colour 

 and composition of the luminosity by the spectroscope, and says 

 that it is not uni-coloured or monochromatic, but compounded 

 ■chiefly of the red and violet rays. Other students regard the 

 substance which produces the light as homogeneous. 



In 1838 Eversmann published an article on a night-shining 

 worm in Russian, and in i87iian English naturalist named Breese 

 delivered an address on the earthworm before the West Kent 

 Natural History Society, from a meagre abstract of which we 

 learn that he had spent some years on the subject of annelid 

 luminosity, having studied it historically from the year 1805, 

 when Viviani wrote on the phosphorescence of the sea, down to 

 the date of his own delivery. According to Breese the lumi- 

 nosity exists in the excreted glutinous material with which the 

 outer skin of the animal is covered. 



More than one creature has at different times borne the name 

 of the phosphorescent worm. In 1837 Duges, a French writer, 

 described a species under this name {Lumbricus phosphoreus), 

 with a girdle extending from the 13th to the i6th segments, and 

 a somewhat flattened body behind. After the lapse of exactly 

 half a century this curious creature was examined again, and 

 named by Giard Photodrilus, or the luminous worm. It has 

 eight setse, just as our common species have, but they are 

 separate, and not in couples. There is no gizzard, nor does the 

 lip dovetail into the segment behind. It is a small, transparent, 

 rose-coloured worm, and decidedly phosphorescent. 



In 1843 when the British Association met at Cork, specimens 

 of an annelid were exhibited by Dr. Allman, which he had dis- 

 covered in the bogs of the south of Ireland, and which was the 

 cause of a luminous appearance. When irritated the worm gave 

 out a phosphorescent light, which is^aid to have been much in- 

 creased by exposing the creature to the vapour of alcohol. The 

 light was of that peculiar soft greenish hue which is character- 

 istic of the phosphoresence observed in light-giving animals, 

 and familiar to most readers in connection with the glow-worm. 

 Another gentleman was reported to have observed the same 

 peculiarity in some annelids which exist in the bogs of Con- 

 naught. I have been unable to find any recent reference to or 

 confirmation of these curious observations. Ten years later Mr. 

 Henry Cox exhibited an earthworm which was phosphorescent 

 at a meeting of the Literary and Philosophical Society of Liver- 

 pool, held November 14, 1853, 



While few records of a trustworthy nature respecting the obser- 

 vation of luminous worms in Britain are available, a good deal has 

 been done by our Continental fellow-v^rorkers. Vejdovsky, 

 who wrote a very valuable work on the various species of an- 



NO. 1220, VOL. 47] 



