454 Mr. H. A. Baylis on a 



Whether it is continuous all the way round, T am unable to 

 state. This duct, which appears to be ciliated, gives off 

 numerous other very fine, ciliated ducts, at right angles to 

 itself, which pass towards the periphery. In transverse 

 sections through the body-wall very delicate tubes, in whose 

 walls no cellular structure has been detected, can be seen 

 passing out between the bundles of longitudinal and circular 

 muscles to the exterior. I have not succeeded in establishing 

 their connection definitely with the ciliated tubes above 

 mentioned, though it seems probable that such connection 

 exists. The ciliated tubes in the mesentery were visible in 

 whole preparations of nephridia, which were removed 

 together with the mesentery, and mounted in glycerine. 

 The distal ends of the tubes, where they pass between the 

 muscles of the body-wall, could, of course, only be seen by 

 the section method. 



These tubes in the body-wall are generally accompanied 

 by fine blood-vessels, while the mesentery is also well supplied 

 with blood-vessels, sending branches to the nephridial lobes. 



In the more anterior segments (i. e., in segments a short 

 distance behind the clitellum) I have not succeeded in finding 

 any trace of ciliated nephridial funnels, or any other kind of 

 internal nephridial opening, in spite of the examination 

 of several whole preparations and a considerable number of 

 sections. In the more posterior segments, however, i. e.. in 

 about the last third of the body, such funnels certainly 

 exist. In each segment in this region there is, near the 

 ventral nerve-cord, a single pair of nephridial lobes of a 

 much larger size than the rest, and each of these organs has 

 a duct which perforates the septum in front and ends in a 

 well-developed funnel in the preceding segment. In other 

 respects, the arrangement of the nephridia appears to be the 

 same as in the more anterior region. 



The external nephridial pores are exceedingly difficult to 

 detect, even in sections, being, apparently, the narrowest of 

 passages between the cells of the epidermis. In spite of 

 caretul examination under a comparatively high power, I have 

 been unable to recognize the pores in pieces of stripped-off 

 cuticle, even when taken from the posterior region, where 

 ihe internal funnels are undoubtedly present. There is a 

 scries of minute lozenge-shaped "impressions" in the 

 cuticle, arranged in a single row round each segment, in a 

 line with the little tubular invaginations surrounding the 

 ehsetae. These, however, are not pores, but are probably to be 

 compared witli the markings said to be the impressions of 



