238 
Destructive Insects and Utility of Birds. 
souglit for by birds, eggs of caterpillars, larvae, caterpillars, 
butterflies, flies, gnats, aphis, ants, snails, worms, &c., and by 
giving to each species its assigned duty and place in the work of 
destruction. Each has its appointed spot, either in the wood, 
field, bush, meadow, garden, or vineyard, on the rocks, or by the 
river-side ; some attack one particular class of insects, others 
another ; some are clever at pecking them off leaves or branches, 
others snatch them up as they fly through the air ; some unearth 
them, others extract them from betwixt bark slits, or pierce the 
wood that shelters them. Each sort of bird is expressly formed 
for the task it is intended it should perform, in the varied shape 
of the beak, feet, and wings ; and each little workman finds it 
necessary for its sustenance to swallow daily an amount of matter 
equal to the weight of its own body. 
In order duly to appreciate the immensity of the work under- 
taken by birds, we will just notice a few facts brought under our 
observation. In a green-house, three full-grown rose-bushes were 
covered by about 2000 of the aphis ; a blackcap {Paims palustris) 
was introduced, and allowed to roam about in freedom, and in the 
space of a few hours the whole multitude of insects were con- 
sumed, and the plants thoroughly cleansed. The titmouse fortu- 
nately multiplies considerably ; they render great service, chiefly 
to shrubs and fruit-trees, eating up millions of caterpillar-eggs. 
Everyone is aware of the enormous quantities of eggs caterpillars 
lay at one time, some species 150, and others 500, 600, and even 
800. The Noctua, for example, lays about 600 eggs twice each 
summer. The titmouse, like most other birds, does not attack the 
hairy caterpillar, but it daily swallows thousands of its eggs. Con- 
stantly in full activity, both in summer and winter, they are ever 
rummaging about trees, sometimes in small groups, and some- 
times accompanied by the European nuthatch (^Sitta Europcea), 
the common creeper (Cert/iia familiaris), and the gold-crested 
wren {Motacilla regulus). They creep into rolled-up leaves, 
under branches and trunks of decayed trees, and diligently make 
away with every insect-egg they may chance to stumble upon. 
Count Casimir Woszicke mentions a conclusive example of the 
signal services these birds render to our gardens : — 
" During the year 1848 au enormo^is quantity of the Bomhyx dispar (the well- 
known enemy of gardens, and which also commits serious depredations in woods) 
Lad devoured the foliage of my trees, so that they were quite bare. I discovered 
in autumn millions of eggs enveloped in a silky sort of covering, and attached 
to the trunks and branches. I had them removed at a considerable expense, 
but soon became aware that the hand of man was powerless to ward off the 
infliction, and resigned myself to the loss of my best trees. But on the 
apjn'oach of winter several bands of the titmouse and the wren {Sylvia troglo- 
dytes) paid daily visits to my trees, and soon the caterpillar eggs were in a 
fair way of diminution. At spring-time about twenty couple of the titmouse 
built their nests in my garden ; the ensuing summer the depredations of the 
