SLUGS AS MYCOPHAGISTS 213 



of the upper part of the stipe of a large agaric, such as Boletus 

 luteus or Lactarius piperatus, remains half-hidden in the hole 

 throughout the day and then may be found by the observer. 



Fig. 75 shows the upper surface of a pileus of Russula hetero- 

 phylla which had been mined under natural conditions in a wood 



FIG. 75. The upper surface of the green pileus of a fruit-body of Russula 

 heterophylla in which large more or less hemispherical holes have been 

 made in the white pileus-flesh by the slug, Arion subfuscus var. 

 aurantiaca, when feeding. The slug is resting in the humped-up 

 position, and from its body to the middle of the upper edge of 

 the pileus extends a slime track. From a wood at Earlswood, near 

 Birmingham, England, Sept. 8. Natural size. 



by Arion subfuscus var. aurantiaca. The slug which did the damage 

 is to be seen resting on the pileus humped-up like a disturbed 

 Arion ater. Fig. 76 shows the damage done by another Arion 

 subfuscus to the hymenial tube-layer of a Boletus elegans. 



Slug-damaged Fungi in an English Wood. On September 8, 

 1920, accompanied by Mr. W. B. Grove, I spent an afternoon in 

 a wood at Earlswood, near Birmingham, England, investigating 

 the damage which the slugs had done to the fungi. Out of several 



