70 PEOCEEDINGS OE THE 



selection by apiarists on account of the increased production of 

 honey, yet this degeneration through the sterility of tlie workers 

 has introduced an element of danger to the race, because the 

 power of reproduction is practically confined to one individual, 

 the queen, and should she come to a sudden end the whole hive 

 might become extiuct." 



Feeding-Tracks of Gasteropoda. By Jaxe LoxGSTAFr, F.L.S. 



[Read 19tb June, 1913.1 



"When at Twitchen, Mortehoe, N. Devon, during the months of 

 August and September last year, I observed curious markings on 

 the glass roof of a cucumber frame which liad been coated with 

 whitening. They were evidently made by some animal and 

 brought to my mind figures of the feeding-tracks of Helix aspersdy 

 Miill,, published by Mr. Taylor in his Monograph of the Land 

 and Freshwater Mollusca of the British Isles (vol. i. p. 260, fig. 520, 

 Nov. 1899, and vol. iii. p. 247, fi-gs. 321 & 322, July 1910). The 

 tracks described by him were similarly made on the whitening on 

 greenhouse roofs, the first at Christchurch, Hants, and the others 

 at Berkhamstead, where they were photographed by the Eev. 

 Dr. ]N"orman. Upon comparison I found, however, that though 

 the tracks in our garden greatly resembled these figures they were 

 evidently formed by a different species. 



As Mr. Taylor considers that each species has a characteristic 

 movement of the head when feeding, it seemed worth while to 

 investigate the matter further. I therefore placed a specimen of 

 H. aspersa on the glass, and found the impression left by it the 

 same as Mr. Taylor's figures. A search amongst some vegetable 

 refuse at the side of the frame brought to view two large examples 

 of Limax maxhnus, Linn. I then put one of these on a pane 



1. 2. 



Helix aspersa. Limax maximus. 



where the whitening was intact, and the result was the production 

 of the track here exhibited, which is exactly similar to those first 

 noticed. 



