224 RESEARCHES ON FUNGI 



and marry cm. away from the second, turned itself around, left 

 the near-by first fungus, and crawled directly toward the distant 

 second one from which the current of air was coming. It was only 

 when the slug was almost touching the first fungus that Stahl was 

 unsuccessful in trying to induce the slug to turn around and seek 

 the second. 



New Chemotactic Experiments. With a view to testing the 

 supposition that slugs find their food, and in particular find fungi, 



by their sense of smell, I have 

 made a series of experiments, 

 under conditions as natural as 

 possible, upon the attraction 

 of Limax maximus to Phallus 

 impudicus and to certain Hy- 

 menomycetes. Before giving 

 an account of these experiments, 

 however, it will be necessary for 

 FIG. 79. Limax maximus, a slug which me to make a few preliminary 



is a mycophagist, showing appear- remar k s upon froth the Limax 



ance when crawling toward food. 



The tentacles are swollen terminally and the Phallus. 



to form olfactory bulbs, the eyes .. ..,. 



being subterminal on the longest According to bimroth and 



pair of 'tentacles ; The fore part of g h ff t j f d f U 



the body bears the mottled mantle 



with its respiratory aperture. The maximUS (Fig. 79) consists of 



hind part of the body is striped. 



About | natural size. From Vol. Ill non - chlorophyllaceoUS SUb- 



of the Cambridge Natural History, e , fanpp< , w hilp. nnvrhinp- oon- 

 by courtesy of Macmillan & Co. ^ S ' Wl 



taining chlorophyll is as a 



rule refused 1 ; and W. A. Gain considers Limax maximus a very 

 dainty feeder, preferring fungi to all other foods. 2 Stahl 3 divided 

 slugs and snails into omnivora and specialists and states that Limax 

 maximus is a specialist which feeds chiefly on fungi. 4 



1 A. H. Cooke, loc. cit., p. 31. 



2 Ibid., p. 32. 3 E. Stahl, loc. cit., p. 15. 



1 Benecke (loc. cit., p. 474, etc.) has recently divided slugs into : (1) pleophagous 

 (Arion empiricorum) which eat a great variety of fungi, green leaves, roots, and 

 fruits of flowering plants ; (2) herbivorous (Agriolimax agrestis) which prefer green 

 plants to fungi whenever a choice can be made ; and (3) mycophagous (Limax 

 tenellus) which eat a great variety of fungi and prefer fungi to higher plants when- 

 ever a choice can be made. Doubtless, according to this scheme of classification, 

 Limax maximus would be regarded as mycophagovs. 



