Anatomy oj the Slug. 33«i 



The kidney (Figs. 4, 6, 7, 8, 13) is a large mass forming a 

 spongework occiipYing the greater part of the mantle cavity. It 

 consists of masses of cells and tubules, the tubules being in 

 greater number and more conspicuous on the dorsal surface. 

 (Fig. 13). These finally open into the ureter, which runs along 

 the dorsal surface of the kidney to the right side, where it 

 descends and opens to the exterior (Figs. 7, 13) just in front 

 of the anus, Aiiiong the cells we can distinguish three kinds — 

 (1) small granular cells, (2) larger clear cells with distinct 

 nuclei, (3) cells which are stained brown and which may not 

 be a distinct kind from the small granular cells, the difference 

 in staining being perhaps due to the presence of inorganic 

 material. 



The Renoimricarclial canal (Fig. 4) is more difficult to make 

 out than in other forms, probably owing to the irregular shape 

 of the kidney and to the presence of a blood vessel in it. In 

 all the three series of transverse sections I examined, it appears 

 to be double at its cardiac end, but the lower branch ends 

 blindly, the upper alone really forming a renopericardial canal. 

 The figure of the section given recalls the figure in J. T. Cun- 

 ningham's paper on " The Renal Organs of Patella. "^ The 

 similarity suggests to me that the lower may be a vestigial 

 second renopericardial canal. 



The Reproductive System. 



In the description given by Mr. Hedley he says : " The 

 genital system appears much contorted at its orifice, after which 

 it divides into three portions — the duct of the genital bladder, 

 which is rather short, twisted, and continuing after reaching 

 the genital bladder, is again expanded into a second sac ; th*^ 

 penis, stout and pyriform, invaginated upon itself and produced 

 into a slender flagellum ; and the vagina, long and slender, and 

 also invaginated upon itself." The following is a description of 

 the reproductive system as made out from specimens I have 

 examined, which dift'er, as will be seen, in a few points from 

 those examined by Mr. Hedley. 



1 Q.J. M.S., vol. xxiii. 



