130 
desired areas (19). The Department of Economic 
Zoology in this University has achieved some good re- 
sults in the larch plantations of the Manchester Corpora- 
tion catchment area around Lake Thirlmere. Here the 
Larch Saw-fly is most destructive, and by fastening on 
the trees large numbers of nesting-boxes suitable for Tits, 
which prey on the larve of this Insect, direct benefit has 
resulted. ; 
Among Mo.Ltuscs the carnivorous Slug Testacella 
alone is valuable. It is a dirty white or yellowish form 
with a small shell situated at the hinder end of the body. 
In injurious Slugs the remains of the shell is always very 
far forwards and in close relation to the respiratory 
pore. It is local in this district, but has occurred in 
several localities. Testacella feeds upon other Slugs, 
Worms, and dead animal matter, and causes no harm to 
vegetation., 
EARTHWORMS are true segmented worms and_ differ 
from Eelworms. In the course of burrowing Earth- 
worms let in moisture and air, the subsoil becomes 
loosened, and direct benefit therefrom is derived. Large 
quantities of earth are swallowed by them, which they 
pass out of their bodies in the form of “ worm casts,” 
commonly seen on lawns and flower-beds. In this 
manner fresh soil is constantly being brought to the sur- 
face, and at the same time Earthworms draw numerous 
leaves and other kinds of vegetation into their burrows 
which they consume in appreciable quantities. Humus is 
partly due to the activities of Earthworms—the bringing 
of soil to the surface and the burying of vegetable 
material is an important factor in the humus formation, 
which adds to the general fertility of the land. Darwin 
calculated that as much as ten tons of soil per annum 
passes through the bodies of Earthworms and is brought 
by them to the surface, over each acre of good land. 
MILLIPEDES (7) belong to the class of Myriapoda 
which are more closely related to the Insecta than to any 
other group. Like the Insects, Myriapods are provided 
with a single pair of feelers or antennz, but they always 
possess more than six pairs of legs, usually a large 
number, and never acquire wings. The two main groups 
of the Myriapods are the Centipedes or Chilopoda and 
the Millipedes or Diplopoda. The former, which are 
beneficial rather than injurious, have a somewhat flattened 
