CHAPTER XXV. 
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PA RA SI T IC 
NESTS . 
Various Parasites — Parasitic Birds — The Cuckoo and its kin— The Cow Bird 
and its nest— Size of its egg— The Blue-faced H(3NEY-eater or Batikin 
— General habits of the bird — Singular mode of nesting — The Sparrow- 
! Hawk and its parasitic habits— The Kestrel, its quarrel with a Magpie — 
The Starling and the Pigeons — The Purple Grakle or Crow Black- 
bird — Its curious alliance with the Osprey — Wilson’s account of the two 
birds— Parasitic Insects— The Ichneumon Flies— The parasite of the 
Cabbage Caterpillar— Its numbers and mode of making its habitation — 
Trap-doors of the cells — The Australian Cocoon and its parasites — The 
Oak-Egger Moth, its cocoons and enemies — Ruby-Tailed Flies and 
their victims — Modes of usurpation — The Cuckoo Flies or Tachinae — 
Parasites on vegetables — The Gall Flies and their home — British Galls, 
their shapes, structures, and authors. 
We now pass to another branch of this inexhaustible subject, 
and come to those creatures that are indebted to other beings 
for their homes. In some cases, the habitation is simply usurped 
from the rightful proprietors, who are either driven out by main 
force or are ousted by gradual encroachment. In other cases, 
the deserted tenement of one animal is seized upon by another, 
which either inhabits it at once, or makes a few alterations, and 
so converts it to its own purposes. In many instances, however, 
the habitation of the parasite is found within the animal itself ; 
and in some cases the entire body forms the home of the para- 
site. 
The kingfisher, for instance, usurps the deserted hole of a 
water-shrew ; and the humble-bee and wasp usually take ad- 
vantage of the deserted burrow of some rat or mouse. In the 
account of the sociable weaver-bird, mention is also made of 
certain little green parrots, which are apt to take possession of 
the great nest, and use it for their own purpose. And in the 
