99 
others. The Rook, for instance, is a bird concerning 
which it is at present impossible to say whether it is a 
beneficial or harmful species. It consumes a vast amount 
of grain but, on the other hand, during the summer it 
devours a great many injurious insects of various kinds, 
including both leather-jackets and  wireworms. The 
Starling also devours a large amount of grain during 
certain times of the year, but this appears to be com. 
pensated by the great quantity of injurious insects which 
the bird consumes at other periods. As many as 197 
leather-jackets, for instance, have been found by Mr. 
Leigh in the crop of a single bird. The Chaffinch is by 
no means as destructive as is commonly believed. It 
consumes large quantities of seeds of such troublesome 
weeds as, dock, knotgrass, hawkweed, and_ especially 
chickweed. Mr. Leigh informs me that although he , 
found grain in the crops of 41 per cent. of the birds which 
he examined, it appeared to have been taken in most cases 
from manure or ricks,in farmyards and not from culti- 
vated land. It must be further added that evidence 
points to the fact that the majority of species of birds 
feed their nestlings on soft-bodied insects and other 
invertebrates. | Consequently even the most destructive 
birds may perform a useful function during that stage in 
their life. 
EELWORMS (4), (5), belong to the group of the Nema- 
toda. They are always small in size and have thread-like 
bodies, the two ends being more or less pointed. They 
can be readily distinguished from the Oligochaeta or 
Earthworms by the total absence of body rings or seg- 
ments. Those which are plant parasites are microscopic 
forms living free in damp soil or inside the tissues of 
plants. Others live in decaying vegetation, and both the 
parasitic and saprophytic forms can be recognised by the 
presence of a spine which can be protruded through the 
mouth and serves to penetrate the cell-walls of plants. 
The Eelworms spread from one plant to another by 
wandering through the soil; and when they leave the dead 
plants they le near the surface of the ground. Fre- 
quently when these animals are numerous it is useless to 
grow susceptible plants in the same patch of soil during 
successive seasons, and then as long an interval as possible 
should elapse between the growing of two crops of the 
same plant. The STEM EELWORM (1 ylenchis devastatrix, 
