THE CAWING OF ROOKS 33 
uttered when we move suddenly beneath the trees, 
and other words are uttered when a bird intrudes 
on the precincts of a neighbor’s nest; there is a 
word when the rook sinks down upon the nest, 
and another word when it flies clear of the rookery 
and makes for the fields. What danger-signals, 
what scoldings, what satisfaction, what exultation, 
what reproaches, what encouragements do we not 
hear? There is no doubt that the members of the 
crow family have fine brains and a notable power 
of vocalization, which training, as in jackdaws and 
ravens, may develop to a remarkable degree; the 
finely innervated musculature of the voice-box 
(or syrinx) is more highly differentiated than in the 
master-songsters, such as blackbird and mavis. 
Experts tell us that the rook has between thirty 
and forty notes, which can be intricately combined. 
This may be best appreciated at the roosting-place 
after the busy breeding season is over and summer 
has come. “A marvelous medley,” said Mr. 
Edmond Selous in his delightful Bird Watchings, 
“a wonderful hoarse harmony. Here are shoutings 
of triumph, chatterings of joy, deep trills of con- 
tentment, hoarse yells of derision, deep guttural 
indignations, moanings, groanings, tauntings, re- 
monstrances, clicks, squeaks, sobs, cachinnations, 
and the whole a most musical murmur. Loud, but 
a murmur, a wild, noisy, clamorous murmur; but 
sinking now, softening—a lullaby. 
IT never heard 
So musical a discord, such sweet thunder.” 
