IN BFRD- LIFE’ IN AN AVIARY 147 
small birds’ nests may come from, and 
which have always puzzled me. These may 
be in many cases the ‘ rootlets and fibres’ of 
books. I have always failed to see how little 
birds could dig up these long thin ‘ rootlets,’ 
and what plants they and the fibres come 
from. Four eggs of the usual greenish-blue 
colour, spotted and streaked with dark purple- 
brown spots (see Part II, p. 187) were laid. 
But in a few days, unfortunately, the hen of 
the other pair of bullfinches who had mean- 
while lost her mate, which had hanged him- 
self by accident with a piece of cotton, set 
about the sitting bird and killed her. (What 
part this act played in the economy of 
Nature is a puzzle I cannot solve.) This 
left a pair still alive. They mated at once, 
and a week after the death of Mrs. Bullfinch 
No. 1, Mr. B. No. r and Mrs. B. No. 2 pulled 
the nest of Mr. and Mrs. B. No. 1 to pieces 
and rebuilt it in some ivy on the wall. Three 
eggs were laid, but they were never hatched ! 
Was it that the pair that mated last were 
real affinities to one another, and should have 
