276 Transactions British Mycological Society. 
place of retreat as darkness is coming on. It was therefore 
necessary for me to make my experiments during the evening 
and night. Slugs and snails possess to a considerable degree 
the power of homing, i.e. of returning to the same hiding place 
day after day, after their night excursions in search of food*. 
My observations have convinced me that Limax maximus is a 
homing slug. The slugs used in my experiment had a fixed 
abode to which they always returned after their nocturnal pere- 
grinations; and the realisation of this fact was of considerable 
help to me in suitably arranging the position of the fungus 
fruit-bodies which I wished the slugs to visit. 
It has been calculated that an average-sized snail of moderate 
pace progresses at the rate of about a mile in 16 days and 
14 hours}. This works out at about 13-3 ft. per hour. The rate 
of movement of Limax maximus is probably not very different 
from that of a snail. On one occasion I found that a Limax 
maximus had travelled from one point to another 12 ft. distant 
in 1 hour and 20 minutes; but the course taken was not the 
shortest possible, so that I have no doubt that the actual pace 
of the slug somewhat exceeded ro ft. an hour. 
Phallus impudicus—the Stink-horn Fungus—as every botanist 
is aware, is one of the most remarkable of all fungi. The young 
fruit-body—sometimes known as a Devil’s Egg—is a soft 
spherical white ball, a little larger than a hen’s egg; and it is 
protected upon its exterior by a thick gelatinous peridium. At 
maturity, the ball suddenly bursts at the top, and then there 
emerges from it in the course of about half-an-hour a sort of 
Jack-in-the-Box made up of a long, white, hollow, spongy, 
bread-like stipe bearing at its free end a conical cap covered 
with dark green slime. The slime contains sugar and millions of 
green spores, and from it issues a very powerful and offensive 
odour. Dung flies are attracted to the fungus by the smell, 
alight upon the green cap, lick up the sweet slime, and carry 
away the spores upon their straggling legs and inquisitive 
proboscides and within their alimentary canals. Thus the spores 
of the fungi are disseminated through the agency of insects. 
The smell from the cap of an expanded Phallus impudicus 
attracts not only flies during the day but also slugs during the 
night. Early in the morning I have several times found an 
expanded fruit-body with a stipe which had been half-eaten 
by slugs during the previous night, the slime left upon the 
fungus and the nature of the damage affording a clear indica- 
tion of the identity of the marauders; and, in the twilight of 
the evening, I have sometimes found a slug, Limax maximus, 
actually upon a Phallus engaged in feeding. 5, 
* A. H. Cooke, loc. cit. pp. 34-36. t Ibid. p..46. 
