Kew : On the Pairing of Limax maximus. 



As soon as the descent is accomplished, Adams adds, an 

 organ is protruded from the genital orifice of each animal. This 

 organ, cylindrical at first, quickly assumes a club shape of from 

 ij4-i 3 /i inches in length. Presently a frilled edge appears along 

 one side as if unrolled, and in a second or two the unrolling is 

 complete, the organs assuming a broad flattened blade-like shape 

 with a thin wavy edge. The organs now intertwine, finally 

 closing round each other so as to form a a, 

 knot, of which it is easy to count the whorls. / 

 The two upper whorls now spread out, and 

 generally overlap in the form of a mushroom 

 or umbrella, leaving the lower part of the 

 knot as before. (Fig. 4.) Sometimes, how- 

 ever, the two outspread whorls, instead of 

 overlapping, curve in different directions ; 

 and sometimes they maintain a nearly hori- 

 zontal position. In colour the organs are 

 milk-white, flecked here and there with dead 

 white. During 5-10 minutes the slugs hang 

 with the body motionless and the tentacles 

 contracted and flabby, while the two out- 

 spread whorls keep revolving upon one 

 another ; and in this extraordinary manner 

 the copulation is effected. This ended, the 

 process above described is reversed. The 

 organs unwind, roll up, and finally disappear. 

 It now usually happens that one of the 

 animals drops to the ground, while the other 

 climbs the cord to the point of support. On 

 one occasion, however, neither slug dropped, 

 but one ascended the thread while the other 

 remained stationary ; and then the other 

 followed, leaving the thread dangling.* 



The present writer has observed one case 

 only, and that in a garden in Hornsey in 

 September 1899. About 10 p.m. the two 

 animals, which differed somewhat in size, were seen on the 

 ground, the one following the other, the mouth of the second 

 resting upon the tip of the tail of the first. At this time the 

 larger slug was leading ; but afterwards, when the animals 

 ascended a post, the smaller led the way. At 10.45, when 



* L. E. Adams, Observations on the pairing- of Limax maximus, Journal 

 of Conchology, IX. (1898), pp. 92-5. 



1901 August 2. 



Fig. 4.— After Adams,. 

 Journal of Conchology, 

 IX. (1898), PI. in., 

 Fig. 9. Reduced. 



