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WILD NORWAY. 
usually in the form of a narrow vertical slit—in the 
trunk of thick trees and close to the ground. Wherever 
the cock bird was heard singing, the nest was pretty 
sure to be within forty yards; and by examining the 
trees for such an opening or hole we seldom failed to 
find the nest, though the eggs were always difficult to 
get at. The tiny hole and the toughness of the grow¬ 
ing wood meant half an hour’s work with the hatchet. 
The nests, in all cases, were very slight, formed of fine 
dry grasses, without hair or other lining. The hen- 
bird, when alarmed by our presence at her nest, uttered 
a hissing note, very like that of its congener, the spotted 
flycatcher (M. grisola ), which latter species was also 
quite common and first observed on May 28 th. 
The pied flycatchers were already laying in May, 
and by June 5th we found full clutches of six eggs. 
Half a dozen pairs were sometimes breeding within a 
space of forty or fifty acres. 
Another exceedingly common species was the 
northern marsh-tit (Parus borealis ), which is also a 
very early breeder, having full clutches of eggs by May 
15 th. After May 25th we found nothing but young 
birds in the nests, and by June 6th the newly-fledged 
broods were seen on the wing. In some cases, natural 
holes are utilized for nesting-sites ; in others, rotten 
trees are bored out to a depth of six or eight inches, 
the tunnel widening towards the bottom. Sometimes 
the eggs are laid on the dry chips without any lining or 
nest; in other cases we found the young ensconced in 
compact warm nests of fur, hair, moss, and the like, 
woven into a bulky structure resembling those of the 
blue and oxeye tits. This marked divergence puzzled 
