EARTHWORM STUDIES. 305 



In 1838 Eversinann published an article in Russian on a 

 night-shining worm (Lumbricus noctilucus, see Zapisk. Kazan. 

 Universit., 1838, pp. 156-7), and in 1871 Breese, an English 

 naturalist, 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 investigations. According to Breese 

 the luminosity exists in the excreted glutinous material with 

 which the outer skin of the animal is covered. It is much to be 

 regretted that (so far as I can learn) the researches of this 

 naturalist have never been given to the public in detail. 



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 16th 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 setae 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. 



A paper on this worm by Barrois appeared some time ago 

 under the title " Sur la presence du Lumbricus (Photodrilus) 

 phosphoreus, Duges, a Groffliers (Pas- de- Calais) " in the 'Revue 

 Biolog.,' iii. pp. 117-119. Beddard places it under the genus 

 PontodriluSy and gives the following brief summary of its 

 characters and history : — 



"Definition. — Length 50 mm.; diameter 2 mm.; number of 

 segments 110. Setae in eight rows. Clitellum xiii.-xvii. Hearts 

 in x.-xii. Sperm-sacs in xi., xii. Spermathecae in ix. with a 

 diverticulum. Habitat — France. 



" This species has been investigated by Giard, who, however, 

 has not yet published an illustrated account of his researches. 

 The main facts in its structure are given in the above definition. 

 In addition to the points there mentioned there exist on seg- 

 ments xii., xiii., and xviii. sacs of modified setae in addition to 



