II SLUGS IN GREENHOUSES 37 



nohile^ a Cattleya^ Vanda^ or similar upright plant for a score 

 of times without ever attempting to ascend into the head of the 

 plant unless it is in bloom, in which case they are certain to find 

 their way straight to the flowers ; after which they will descend, 

 and return to some favourite hiding-place, often at the opposite 

 end of the house." ^ Mr. R. Warner has "actually seen many 

 little slugs suspending themselves by slime-threads from the 

 rafters and descending on the spikes of the beautiful Odonto- 

 glossum alexandrae ; and thus many spikes, thickly wadded 

 round with cotton wool (which the slugs could not travel 

 over), and growing in pots surrounded by water, had been 

 lost." 2 Perhaps the most singular instance of a liking for a 

 particular food is that related by Mr. E. Step.^ In a London 

 publishing house, slugs were observed, during a period of nearly 

 twelve months, to have fed almost nightly on the colouring 

 matter in certain bookcovers, and though the trails were often 

 seen over the shelves, and cabbage and lettuce leaves laid down 

 to tempt the creatures, they continued their depredations with 

 impunity for the time above mentioned. 



Limnaea peregra has been observed feeding on old fish-heads 

 thrown into a dirty stream, and a large gathering oi Limnaea 

 stagnalis has been noticed feeding upon an old newspaper in a 

 pond on Chislehurst Common, ' so that for the space of about a 

 square foot nothing else could be seen.' * "" 



Tenacity of Life. — Land Mollusca have been known to 

 exhibit, under unusual conditions, remarkable tenacity of life. 

 Some of the most noteworthy and best authenticated instances 

 of this faculty may be here mentioned. 



The well-known story of the British Museum snail is thus 

 related by Mr. Baird.^ On the 25th March 1846 two specimens 

 of Helix desertorum^ collected by Charles Lamb, Esq., in Egypt 

 some time previously, were fixed upon tablets and placed in the 

 collection' among the other Mollusca of the Museum. There 

 they remained fast gummed to the tablet. About the 15th March 

 1850, having occasion to examine some shells in the same case, 

 Mr. Baird noticed a recently formed epiphragm over the mouth 

 of one of these snails. On removing the snails from the tablet 



1 Garden, v. p. 201, quoted by Kew, ut sup. 



2 Kew, ut sup. 3 Science Gossip, 1883, p. 163. 

 * T. D. A. Cockerell, Scieiice Gossip, 1885, p. 211. 



5 ^nn. Mag. Nat. Hist. (2) vi. (1850) p. 68. 



