278 Transactions British Mycological Society. 
The above observations show that Limax maximus, under 
natural conditions, guided by its sense of smell, sometimes 
travels from 21 to 24 ft. toward an expanded fruit-body of 
Phallus impudicus and that, upon coming in contact with the 
fruit-body, it feeds upon the stipe. 
I employed Phallus impudicus for my first experiments upon 
the chemotaxis of slugs because of its very powerful odour and 
the convenience with which I could procure and handle its 
fruit-bodies; but I have found that similar experiments can be 
performed with Boleti and Agaricineae. 
Experiment IV. On September 8, I procured three fresh 
fruit-bodies of Boletus scaber from a wood and, in the evening 
of September 9, placed them upon the gravelled area at a dis- 
tance of 10 ft. from the border. During the night a slug came 
from the border across the gravel to the fruit-bodies and ate 
three holes in the top of one of the pilei.. A similar experiment 
made at the same time with a large fruit-body of Russula 
heterophylla was also successful. 
Experiment V. The next evening, September 10, about 8 p.m., 
I placed upon the gravel three little heaps of hymenomycetous 
fruit-bodies. In the first heap were the three fruit-bodies of 
Boletus scaber which had been used the night before, in the 
second three fruit-bodies of Cortinarius caninus, and in the third 
three fruit-bodies of Russula nigricans. Each heap was made 
at a distance of 12 ft. from the border and the three heaps were 
in a row, the central heap being that of Boletus scaber and the 
intervals between the heaps being 4 ft. Having had considerable 
difficulty in some of the previous experiments in tracking the 
slime-trail upon the gravel owing to the intermittency or thin- 
ness of the trail and owing to the effects of dew, I placed some 
large fern leaves in a line along the edge of the gravel by the 
border, so that, if a slug crossed the line, it would leave a trail 
behind which could be easily detected. The night was a very 
dark one. About 10 p.m. I went out with a lighted taper to 
see what was happening. On examining the fern leaves I found 
upon the leaflets a shinging slime-trail, the direction of which 
proved that the fern line had already been crossed by a slug. 
I then hunted about on the gravel and found the slug, a Limax 
maximus, about 4 inches long, actually on its way to the fungi. 
The slug was already 4 ft. from the border whence it had come 
and was heading in the right direction to reach the row of 
fungus heaps some 8 ft. distant. I noticed, however, that the 
path of approach to the fungi was by no means a straight line 
but was made up of a series of curves. At 10.45 p.m. I found 
the slug about 4 ft. from two of the heaps of fungi, and at 
11.20 p.m. I found the slug actually upon one of the fruit- 
