CELLAR SLUG. 281 



PLATE V. 



CELLAR SLUG (Limax flavus, s. variegatus), 



Dissected so as to show its digestive, circulatory, respiratory, nervous, and reproductive systems. 



THE muscular envelope has been separated from the foot along 

 the left side, and turned over to the right, together with the shield- 

 shaped mantle and the organs it overlies. The buccal mass and nerve 

 collar, together with the salivary glands, have been displaced a little to 

 the left, on which side of the animal's body the stomach and bilobed 

 liver have been fastened out. Some of the nerves, muscles, and arteries 

 have been cut away. The oesophagus and buccal mass have been pulled 

 a little forward through the nerve-collar, and occupy much the same posi- 

 tion relative to it that they do when in life the buccal mass and head are 

 thrust forward. The two first convolutions of the intestine have been un- 

 coiled, and it has thus been drawn as taking a much less sinuous course 

 than it does in nature from its commencement at the pylorus to the point 

 where it comes into relation with the dorsal integument and shield, and 

 hooks round the muscle which retracts the buccal mass and tentacles. The 

 generative organs have been detached from their normal connections, and 

 are arranged on the right side ot the animal's head. Their volume, as 

 drawn here, is small in comparison with that which they attain in the breed- 

 ing season. The upper tentacles, the nerves which supply and the muscles 

 which retract them, have been cut through, and turned forward so as to lie 

 between the generative apparatus on the right hand and one of the salivary 

 glands on the left. The right lower tentacle is seen between the right 

 upper tentacle and the vestibulum of the reproductive system. 

 a. Locomotive disk or 'foot 5 ' passing upwards at the sides into the 

 general muscular envelope of the various organs of the animal's 

 body, from which it is limited off by a furrow. Its internal circular 

 coat is raised into two corrugated ridges along the greater part of the 

 middle line of the body by the underlying supra-pedal gland. This 

 gland is found in many Gastropoda, and is of very large size in this 

 Slug. Its aperture lies above the foot and below the head, its duct 

 is long, and lined by ciliated epithelium of two kinds, of which one is 

 perhaps sensory (? olfactory). The gland cells are aggregated on 

 either side of and below the duct. The supra-pedal gland must be 

 carefully distinguished from the pedal which secretes the mucous 

 thread by which certain Prosobranchiata suspend themselves to the 

 surface of the water, and which opens on the sole of the foot an- 

 teriorly. See p. no, and lit. p. 112. 



