156 KEW: THE FACULTY OF FOOD-FINDING IN GASTROPODS. 
food at a distance, would be certain in many cases to find baits, and 
other favourite food-substances, during their wanderings by mere 
accident ; for in gardens and elsewhere slugs and snails often exist 
in immense numbers, and on favourable nights we see them crawling 
about in all directions ; whelks, etc., in like manner are probably 
very numerous On certain parts of the sea-bottom. Moreover, as 
Mr. Gain suggests, slugs and snails on going out to feed are often 
likely to devour the first suitable food they find, and to retire in the 
morning to the nearest refuge ; from which, in such case, they would 
from various starting-points, of course, would be likely to come 
across the same food; so that we can readily understand that a bait, 
for instance, exposed during several days in the same place, might 
ecome surrounded by quite a number of molluscs, all of which 
might have found it accidentally in the first instance. A similar con- 
sideration applies, probably, in the case of marine gastropods. Slugs, 
it might be remarked, congregate for shelter, often in considerable 
numbers, under pieces of board or tile placed on the ground as traps 
in gardens,’ and, similarly, snails collect in numbers in empty flower- 
pots. These traps, certainly, are accidentally found. It is worth 
mentioning, however, in this connection, that when Mr. Gain placed 
side by side, on bare ground in his garden, a tile affording shelter 
only, and another with orange-peel beneath it as a bait, only seven 
slugs (six garden-slugs, Arion hortensis, and one Arion circumscriptus) 
were taken under the former in three days, while the latter, during 
the same period, yielded seventeen (fourteen garden-slugs, one A7i0# 
circumscriptus, and two field-slugs, Agriolimax agrestis). This experi- 
ment, as far as it goes, seems to show that the bait was scented, and 
it cannot reasonably be doubted, I think, but that gastropods are able to 
scent or in some way perceive their food at least at a little distance. 
Otherwise, as it seems to me, and as already indicated, some of the 
will be remembered, in orchid-houses where slugs do not commonly 
exist in vast numbers. Bee-hives, I suppose, are hardly likely to be 
entered by slugs accidentally. As Mr. Nunneley remarked in 1834; 
slugs are soon attracted in numbers to favourite food ‘even when 
placed at some distance from their accustomed haunts ;’? and 
1 See ‘ Garden,’ v, (1874), 201-2; viii. (1875), 306; and ‘ Gardeners’ Magazine,’ xviii. (1875), 
114, 
2 T, Nunneley, Trans, Leeds Philos. and Lit. Soc., i., p. 74. 
URE 
Naturalist, 
