PHOSPHORESCENCE.—Phosphorescence has been observed in several species of Oligochaeta. The most noteworthy instance of recent times is the discovery by Giard of the small worm which he called _Photodrilus phosphoreus_ at Wimereux. During damp weather it was sufficient to disturb the gravel upon the walks of a certain garden to excite the luminosity of these Annelids. In all probability this species is identical with one whose luminosity had been noticed some years before (in 1837) by Dugès, and named by him _Lumbricus phosphoreus_. According {369}to Giard, the light is produced by a series of glands in the anterior region of the body debouching upon the exterior. This same worm has since been found in other localities, where it has been shown to be phosphorescent, by Moniez[422] and by Matzdorf[423]. It is remarkable that in some other cases the luminosity, though it exists, is very rarely seen. The exceedingly common Brandling (_Allolobophora foetida_) of dunghills has been observed on occasions to emit a phosphorescent light. This observation is due to Professor Vejdovsky,[424] and was made "upon a warm July night of 1881." He thinks that the seat of the light is in the secretion of the glandular cells of the epidermis, for when this and other worms are handled the phosphorescence clings to the fingers, as of course does the mucous secretion voided by the glands. Phosphorescence has been observed also in some other families of Oligochaetes. The late Professor Allen Harker noticed a small worm in marshy ground in Northumberland which emitted a distinct light, and which was subsequently identified as a member of the family Enchytraeidae. GEOGRAPHICAL DISTRIBUTION.[425]—In the succeeding pages some of the details of the geographical range of the Oligochaeta will be found. The present section deals with a few generalities, which appear to result from an examination of the facts.