"I should think the eggs would have frozen hard and been spoiled," said
Nat.

"No, the old Owl sat on them ever so tight and would hardly budge to let
the miller see them. We didn't stay long, for the Owl was a savage big
thing, nearly two feet high, with yellow eyes and long feathers sticking
up on its head like horns."

"A Great Horned Owl," said the Doctor. "I only wonder that it let the
miller go near it at all; they are generally very wild and fierce."

"This one was sort of friends with the lumbermen," continued Rap, "for
they used to hang lumps of raw meat on the bushes for it, and they said
it kept the rats and mice away from the camp and was good company for
them. It frightened me when I heard it first; it gave an awful scream,
like a hurt person. After a while another one began to bark like a dog
with a cold, just like this--'who-o-o-o--hoo--hoo--hoo.' And, Doctor,
one of the lumbermen told me that with Owls and Hawks the female is
mostly bigger than the male. Do you think that is so? Because with
singing birds the male is the largest."

"Among cannibal birds the female is usually the largest," answered the
Doctor, who was pleased to see that Rap so often had a "because" for his
questions. "These birds do a great deal of fighting, both in catching
their living prey and holding their own against enemies; and as the
female stays most at home, being the chief protector of the nest, she
needs more strength."

"Some singing birds are real plucky too," said Rap. "That same year I