280 Transactions British Mycological Society. 
was only 4 ft. The slug, as the track showed the next morning, 
seems, during these two hours, to have wandered more or less 
round and round in a knotted manner as if it had had some 
difficulty in detecting the scent of the fungi. As it happened, 
the slug was obliged to cross the line where the heaps of fungi 
had lain during the previous night and day, and it is therefore 
possible that the fungi had in some way scented the ground 
and that the scent had mis-led the slug. It is also possible that 
variations in air currents took place in such a way as to send 
the odour of the fungi in the heaps toward the slug only very 
intermittently. But, whatever may be the true explanation, it. 
is certain that between II p.m. and 1 a.m. the slug lost much 
time and spent a considerable amount of energy in fruitless 
wandering. 
There was nothing upon the gravel for the slug to eat except 
the fungi I had placed there and, if the slug had continued in 
the direction in which it set out without finding the fungi, it 
would have traversed a gravel desert 60 ft. across. 
At 2 a.m., as soon as I had found the slug which had been 
under observation, upon a Russula nigricans fruit-body, I 
hunted carefully over the gravelled area for other slugs. I could 
find one more slug only—another Limax maximus—which had 
come out of the border and was heading straight for the row of 
fruit-body heaps from which it was only 8 ft. distant; but 
whether or not this second slug ever reached one of the heaps 
I cannot say, as at 2.5 a.m. I retired to bed and, in the morning, 
could not clearly distinguish the trail. 
In the morning of September 12, I found that the slug which 
had visited the Russula nigricans fruit-bodies was no longer to 
be seen upon the gravel. Doubtless, it had once more retired 
to the border. It is doubtful whether the return journey could 
have been accomplished in less than two hours. It appears, 
therefore, that our Limax maximus, with the object of feeding 
upon a fungus and then returning home, must have spent some 
six or seven hours in a single night in wandering over the 
gravel where the fungus was. Such an effort shows how strongly 
fungi attract slugs of the Limax maximus species. Doubtless, 
the slugs in woods are also attracted to fungi from a distance 
of many feet. In view of my observations on Limax maximus, 
the success with which slugs in woods find out the fleshy 
Hymenomycetes can no longer be a matter for astonish- 
ment. 
Experiment VII. On September 12, I made a fourth experi- 
ment with hymenomycetous fruit-bodies. On this occasion I 
used the Russula nigricans and Cortinarius caninus heaps alone, 
as the Boletus scaber fruit-bodies had now become thoroughly 
