/few : On the Pairing of Lima x max/' nuts, 251 



less remarkable, further, are the other circumstances attending 

 the union : the intertwining of the animals' bodies, often with 

 great regularity and closeness ; the great development and 

 extreme mobility of the non-erectile organs of copulation ; their 

 suspension below the heads of the animals ; their rapid and 

 intimate intertwining ; their extraordinary sinuated expansions, 

 etc. All these things, however, are probably eclipsed by the 

 character of the copulation itself. It is necessary, if one is to 

 attempt to understand the process, to remember that each 

 individual of animals of this kind possesses both male and 

 female organs ; that there is but one genital pore ; and that 

 this pore, in Limax maximus, has little or no vestibule, the penis, 

 the oviduct, and the duct of the receptaculum setninis opening 

 to the exterior practically at the same spot. Further, one may 

 advantageously refer to a figure of the genitalia of this particular 

 slug — as seen when dissected from the body of the animal — 

 such as that given by Baudelot, or that of Scharff, Scientific 

 Transactions of the Royal Dublin Society, IV. (1891), PI. LVII. 



One finds it impossible, at first, to reconcile the organs as 

 thus figured, with the appearances presented during pairing. 

 The penis, compared with that of other slugs, is certainly long ; 

 but it seems quite inadequate. There is no doubt, however, 

 that the organs presented to view are the penes, everted, and in 

 a state of great distension. This is clearly shown by Baudelot 

 {who severed the organs in one of the copulations observed by 

 him), and also by Mr. W. M. Webb, who examined a coupled 

 pair of organs severed by Mr. Adams. In the latter case, one 

 of the penes was but half everted ; it bore interiorly the retractor 

 muscle, cut off short, and a part of the vas deferens. The other 

 was completely everted, and showed the peculiar ' frill ' on one 

 side ; the vas deferens could be traced down the interior of the 

 tube, but the retractor muscle was not discovered.* The 

 matter had previously been made clear by Purkyne, who gives 

 a drawing, of which Fig. 5 is a cop}'. We have already seen 

 that this naturalist bound the extruded organs of his paired slugs 

 close to the genital opening, his purpose being to compare the 

 anatomy of the animals thus treated with that of others not 

 taken in copulation. He found the extruded organs to be the 

 penes in a state of complete eversion. A7 in the figure is 

 the genital opening, the organ below being the everted penis ; 

 the vas deferens (yd) and the retractor muscle (/;/) run dow n 



* W. M. Webb, in Adams, I.e. 



1001 August >. 



