THE CAWING OF ROOKS 37 
knows that the rook differs from the crow in habit 
and color, in the loss (after the first year) of the 
feathers round the back of the beak, and so on, 
but it is instructive, as an illustration of the way in 
which specificity penetrates through and through 
a creature, that while the inside of the mouth is 
always pale flesh-color in the young of the carrion- 
crow, it is first dark flesh-color and then slaty in 
the rook. 
In many parts of the country it has been the 
custom to watch the rooks with particular interest 
at Easter-time, for from the manner of their flight 
and the mood of their cawing, hints of coming events 
were believed to be obtainable. But most of those 
who watch rooks to-day find sufficient interest 
in their present and past. We wish one of those 
ornithologists who give us admirably intimate 
studies of the “Home Life” of particular birds 
would make a detailed critical study of the rook. 
There are so many points of great interest. Like 
many creatures well endowed with brains, rooks 
exhibit what must be called play. There are gambols 
and sham-fights, frolics and wild chases, in which, 
curiously enough, jackdaws and lapwings sometimes 
become keenly interested. But who knows the 
real truth about rooks posting sentinels, which is so 
often alleged? What has been called the “ ecclesias- 
tical air” of the rook, enhanced by the white about 
the head, gives spice to an apparent humorousness, 
and there is no doubt of their wisdom.’ But who 
knows the significance of the vast congregations 
