
бо BRITISH ЕЕКМ5 
which bore down the remaining midrib and stalk of Ше frond and 
eventually pupate in the soil near the caudex. We have never been 
able to discover this fly, but have been informed that it somewhat 
resembles a house-fly. The only remedy for this is to cut off the 
frond some inches below the wilted portion immediately the 
flagging is seen, thus, of course, removing the eggs and preventing 
development of the grub. Cases of similar attacks in the late 
summer have been reported to us, but with us they have been 
confined to the spring. А tiny black snail, Helix alliaria, so called 
from its pungent onion-like odour, is sometimes a nuisance, gnaw- 
ing through the bases of even large fronds, which drop mysteriously 
and without warning in a very provoking fashion. Fortunately, 
this foe 15 not numerous. Slugs and snails generally should be sought 
for and killed when traces of them appear in the shape of slime ; but 
Ferns do not appear to appeal to them very strongly. Worms 
should be turned out of pots, if their casts are seen, as they tend to 
choke the drainage and sour the soil. Wood-lice should be kept in 
check as far as possible by destroying them in their haunts under 
the pots and elsewhere; but as they are chiefly feeders on dead 
material they are not nearly so inimical to living plants as the other 
invaders named. 

