CHAPTER VIII 



SLUGS AS MYCOPHAGISTS 



Introduction Slug-damaged Fungi in an English Wood- Slugs and Poisonous, 

 Acrid, or Cystidia-bearing Agaricineae Absence of Slugs from a Wood in 

 Central Canada Some Conclusions The Finding of Fungi by Slugs Previous 

 Chemotactic Experiments New Chemotactic Experiments Experiments I, 

 II, HI, IV, V, VI, and VII Slugs and Mustard Gas Conclusions 



Introduction. Slugs eat many fleshy fungi ; and in woods and 

 gardens in Western Europe one can often find fruit-bodies which 

 have been more or less damaged by these animals. Fungi, there- 

 fore, especially in certain localities and in certain seasons, must 

 be considered as an important source of slug food. Among the 

 fungi which slugs attack may be mentioned : species of Amanita, 

 Pleurotus, Russula, Psalliota, Coprinus, Boletus, Polyporus, and 

 Phallus. Leathery fungi, e.g. Polysticlus versicolor, Stereum Tiir- 

 sutum, and SchizopJiyllum commune, and gelatinous fungi, e.g. 

 Hirneola auricula-judae and Auricularia mesenterica, are generally 

 avoided. A few experiments upon the edibility of fungi for slugs 

 are recorded in Volume I of these Researches. 1 



A fruit-body which has been partially eaten by a slug can be 

 easily recognised : (1) by the peculiar manner in which it has been 

 rasped and mined, and (2) by the slug's slime tracks. Slugs are 

 nocturnal animals. During the day, they hide under soil or in 

 dark crevices ; but, as darkness comes on, they emerge from their 

 places of concealment and seek their food. They therefore visit 

 the fruit-bodies of fungi during the night, but, as a rule, retire 

 from them with the advent of day. Sometimes, however, a slug 

 which has made a hole on the under side of the pileus or in the top 



1 Vol. i, 1909, p. 229. In Trans. Brit. Myc. Soc., vol. vii, 1922, pp. 270-283, 

 I published a paper called " Slugs as Mycophagists." The present Chapter is that 

 paper with illustrations and additional remarks. 



