KEW: THE FACULTY OF HOMING IN GASTROPODS. 309 



enemies. Those not protected by a shell, if they had to remain 



uncovered during the day-time, would be liable also to be scorched 



up by the sun ; this might happen to slugs living upon walls, where, 



as is often the case, the holes in which they shelter are not numerous ; 



and the same remark applies probably to those inhabiting precipitous 



rocks. We thus see that the faculty of homing is of great use as 



enabling the animals to escape destruction, and it is, perhaps, not 



surprising that the habit, together with the necessary power of memory, 



should have been acquired. 



I have here put together such information as I have been able to 



collect, but this paper will be very incomplete. I suppose most 



naturalists of wide experience in the field and acquainted with the 



records of others will be able to call to mind additional facts. 



I have much pleasure in acknowledging indebtedness to Mr. Ashford, 



Mr. R. Standen, Mr. W. A. Czain, Mr. Sherriff Tye, and Mr. G. K. 



Gude, who have courteously furnished information and otherwise 



assisted, and to Mr. Romanes, who has obligingly looked over 



the manuscript. 



SLUGS. 



Probably most slugs resort to any convenient hiding-place near 

 their feeding-grounds, and do not inhabit particular spots or homes. 

 They congregate under pieces of board or tile placed upon the 

 ground as traps in gardens,* as do snails in empty flower-pots. 

 Mr. Gain believes that when a slug or snail goes out to feed it devours 

 the first suitable food it finds, and retires in the morning to the 

 nearest refuge, and he tells me that he has frequently left slugs and 

 snails {Zonites) in comfortable quarters, intending to find them again 

 when wanted, but, on re-visiting the spots, has generally been dis- 

 appointed. On this subject, A. Binney says of terrestrial molluscs : — 



Numbers frequently resort to the same place, but this in the Helicidae seems 

 a mere matter of accident, while in the introduced species of Limacidse it appears 

 to indicate a gregarious habit, as they prefer to crowd together and lie in close 

 contact with and upon each other. These last are said by some to occupy per- 

 manently the same retreat, but the assertion is probably incorrect. They often, 

 and perhaps generally, remain in the immediate vicinity of the place where they 

 procure their food, and hence they often resort to the same place of shelter ; and 

 as many of them ha%'e frequently been observed in the same place, they have been 

 thought to be the same individuals. But when one set of individuals is destroyed, 

 another soon takes their place, and whenever a new shelter is provided, by the 

 accidental presence of fragments of wood in suitable situations, it is immediately 

 resorted to by them. ('Terrestrial Air-breathing Molluscs of the United States, 

 i (1851), 193). 



There seems reason to believe that the Yellow and Great Grey 

 Slugs {Limax flavus and L. maxiinus), when living between the 



'Garden,' v (1874), 201 ; viii (1875), 306. 

 Oct. i8qo. 



