18 EGGS AND EGG-COLLECTING. 
occurred in the neighbourhood of Skegness, where a pair 
of Marsh Titmice selected a farmer’s letter-box for incuba- 
tion purposes, and although it was opened twice daily, and 
the materials with which the birds began to build were 
several times cleared away, they doggedly persisted in their 
efforts, and eventually succeeded in making a nest and 
depositing the usual number of eggs. 
One of the strangest cases of all, and I should think 
the most remarkable on well authenticated record, recently 
occurred near Colchester, where a pair of Common Wrens 
built their nest inside the skeleton of a hooded crow, which 
had been brought to justice and hung up as a warning to 
other winged depredators. 
These odd positions and situations are evidently not 
chosen for purposes of concealment from man, at any rate; 
indeed, it is a question whether some of them are not 
adopted to secure the advantage his presence affords against 
the incursions of predatory birds and animals. And, on 
the other hand, if these seeming departures from instinct 
be admitted as due to reason, it seems strange that whilst 
some birds are capable of this, others exhibit what seems 
to human understanding profound stupidity. I have 
known birds vainly try to build in positions where it was 
impossible for a nest to rest, each piece of material falling 
to the ground, until sufficient had been collected for a great 
many nests; yet the bird kept on collecting sticks, moss, 
and grasses, until probably she was obliged to drop her 
eggs in the fields. This is not a solitary instance, nor 
only once attempted, for close observation proved that the 
same inexplicably vain effort was continued from year to 
year, but whether by the same birds or not it is of course 
impossible to say 
