NEW GENEKA AND SPECIES OE EARTHWOEMS. 261 



nephridium belonging to that segment to be discovered. The 

 nephridia are paired, and are not absent from the genital seg- 

 ments. 



The buccal cavity occupies the first three segments of the 

 body ; as usual, the cerebral ganglia lie at the junction of this 

 with the pharynx. The epithelium of the first section of the 

 buccal cavity is like that which covers the prostomium ; that 

 is to say, the cells are narrow and deep, with a few oval 

 glandular cells scattered among them ; there are, indeed, more 

 glandular cells than in the prostomial epidermis, but not so 

 many as in the epidermis of the general body surface. Behind 

 this region, which is about half the length of the buccal cavity, 

 the tube becomes contorted so as to be able to be stored away 

 in the limited space available ; this region is lined with 

 columnar cells considerably wider than those of the first sec- 

 tion of the buccal cavity. This part of the buccal cavity has 

 an extraordinarily rich nervous supply ; these nerves are not 

 merely delicate filaments concerning whose existence there 

 might be some doubt, but stout nerves which form an almost 

 continuous layer (probably really a plexus) beneath the epi- 

 thelium — immediately beneath it, and divided from it by no 

 structures. These nerves are exceedingly conspicuous from the 

 fact that the nerve-cords are unstained, and therefore contrast 

 with the deeply stained epithelium beneath which they lie ; 

 frequent nuclei are interspersed among the fibres. These 

 nerves are connected with a large visceral ganglion. A rich 

 nervous supply, limited to the anterior part of the alimentary 

 tract (or at least most highly developed there) of an animal 

 which, as it swallows all before it, can hardly be accused of 

 possessing a very delicate or discriminating palate, is remark- 

 able. Earthworms, however, in addition to swallowing the 

 earth as they tunnel their way through it, draw down leaves 

 in^ their burrows ; for the selection of these leaves the nervous 

 mechanism referred to may be useful. It is also possible that 

 the buccal cavity is everted as in Perichseta; but although 

 I received the worms alive I did not notice anything of the 

 kind. In that event it might be used as a tactile organ, which 



VOL. XXXIV, PARI III. NEW SER, S 



