144 FERN GROWING 



Wentwood, Matherne, Tintern, St. Pierre, Portskewet, New- 

 port, Cardiff, Clifton, and Bath ; but Dr. Jeffreys considered 

 them to have been introduced. Since Dr. Jeffreys' death they 

 have been seen in so many other locaHties that they are now- 

 considered as British slugs. They live underground in the 

 daytime, and are only to be seen on damp nights by the aid 

 of a lamp. They are very voracious ; one kept in a box with 

 ten worms and ten slugs had destroyed them all in two days. 

 They descend worm-holes and will seize the worms, whilst 

 the shell at the other extremity is a perfect protection against 

 anything following them. 



Of the eighty-seven land slugs there are only eighteen 

 that give trouble to the gardener : these are Amalia marginata 

 (Miiller), A. gagates (Draparnaud), Arion ater (Linneus), A. 

 Bourguignati (Mabille), A. hortensis (Ferussac), A. subfuscus 

 (Draparnaud), Eulimax agrestis (Linneus), E. maximus 

 (Linneus), E. cinereo-niger (Wolf), Helix aspersa (Miiller), H. 

 concinna (Jeffreys), H. hispida (Linneus), H. hortensis (Miiller), 

 H. nemoralis (Linneus), H. rufescens (Pennant), Zonites alli- 

 arius (Miiller), Z. cellarius (Miiller), and Z. nitidulus (Drapar- 

 naud). Some of these species have many varieties — Arion ater 

 has lo, Helix aspersa 20, and Helix nemoralis 23. Helix 

 aspersa is a great pest, but the author has never found it on 

 the Keuper districts. 



The slugs of large size are very destructive, and require 

 to be constantly hunted for, or they will return night after 

 night to the same plant. The Adiantum and Scolopendrium 

 are the Ferns that suffer most. One visit at night is not 

 sufficient, as some are on the move early, and some late. All 

 slugs, wood-lice, centipedes, and many other insects * feed 



* One of the most useful insects is the ladybird {Coccinella). There are several 

 common species, and they should be collected for the greenhouse, as they live 

 on nearly all the insect pests. The larva of the ladybird is very voracious. The 

 author placed two of them on a pelargonium that was swarming with Aphis (green 



