“Nothing makes a dog madder,” said Mitchell, “than to have another dog come outside his fence and sniff¹ and bark at him through the cracks when he can't get out. The other dog might be an entire stranger; he might be an old chum, and he mightn't bark—only sniff—but it makes no difference to the inside dog. The inside dog generally starts it, and the outside dog only loses his temper and gets wild because the inside dog has lost his and got mad and made such a stinking² fuss about nothing at all; and then the outside dog barks back and makes matters a thousand times worse, and the inside dog foams⁴ at the mouth and dashes the foam³ about, and goes at it like a million steel traps.  
“I can't tell why the inside dog gets so wild about it in the first place, except, perhaps, because he thinks the outside dog has taken him at a disadvantage and is 'poking⁵ it at him;' anyway, he gets madder the longer it lasts, and at last he gets savage⁶ enough to snap off his own tail and tear it to bits, because he can't get out and chew up that other dog; and, if he did get out, he'd kill the other dog, or try to, even if it was his own brother.
 
“Sometimes the outside dog only smiles and trots⁷ off; sometimes he barks back good-humouredly; sometimes he only just gives a couple of disinterested⁸ barks as if he isn't particular, but is expected, because of his dignity and doghood, to say something under the circumstances; and sometimes, if the outside dog is a little dog, he'll get away from that fence in a hurry on the first surprise, or, if he's a cheeky little dog, he'll first make sure that the inside dog can't get out, and then he'll have some fun.
 
“It's amusing to see a big dog, of the Newfoundland kind, sniffing⁹ along outside a fence with a broad, good-natured grin on his face all the tim............