80 Mr. F. E. Beddard on a 



dorsal vessel and its branches ; the relationship of the peri- 

 toneal cells to the other Llood- vessels is supposed to be rather 

 to the advantage of the cells than. of the blood; the cells 

 grow and multiply, and then break off to perform their useful 

 function in life elsewhere. This, however, does not explain 

 tlie association of the cells with the nephridia in Oordiodrilas 

 tenuis and in other species. So far as the facts enable a 

 generalization, it seems that heat or damp or both combined 

 are related to the abundance of these cells upon the nephridia. 

 Excretion may be more rapid under these circumstances. 

 When the excretory epithelium — the " drain-pipe " cells — is 

 in action, the products of their activity must be thrown off 

 in every direction, not only into the lumen of the tube. It 

 may be therefore that the peritoneal cells serve as store- 

 houses of this waste matter, which is kept close at hand ready 

 for excretion, instead of being thrown off into the body-cavity 

 and having to be laboriously re-collected. The coelom, as in 

 all OUgochseta with the exception of ^olosoma, is divided 

 by septa into chambers corresponding with the external 

 metamerism. Some of the anterior septa, as is also usually 

 the case, are of much greater thickness than the others. 

 This applies to the septa separating segments v.-xii. 



With regard to the alimentary canal, there seems in the 

 first place to be no gizzard. The single ventral calciferous 

 gland (the minute structure of which will be described under 

 Gordiodrilus elegans) is present. The intestine has no typlilo- 

 sole. 



The reproductive organs I am fortunately able to describe 

 more completely ; there appears to be only a single pair of 

 testes J which occu])y the usual position in segment xi. {i. e. 

 attached to the front wall of that segment). Owing to the 

 fact that the intersegmental septa are very much broader than 

 the diameter of the body, the successive septa in the anterior 

 region of the body, as is so frequently the case with the 

 OligochEeta, are placed within each other like a series of cups, 

 the concavity being forward. Owing to this disposition of 

 the septa, whicli seems to be exaggerated in Gordiodrilus 

 tenuis, the testis of each side is pressed between the septum 

 and the parietes. The septum separating segments x./xi. 

 runs for a considerable distance nearly parallel to the parietes; 

 in the narrow space left between the two the testis is wedged. 



The sperm-sacs occupy segments x.-xiii. about ; but I have 

 not been able to make out their arrangement very clearly ; 

 like most of tl)e organs lying in the centre of the body, they 

 were but slightly stained. 



The vas deferens like the testis is single on each side of 



