Quotation from: The Call of the Wild

Written by: Jack London

For the most part, however, Buck's love was expressed in
adoration. While he went wild with happiness when Thornton
touched him or spoke to him, he did not seek these tokens. Unlike
Skeet, who was wont to shove her nose under Thornton's hand and
nudge and nudge till petted, or Nig, who would stalk up and rest
his great head on Thornton's knee, Buck was content to adore at a
distance. He would lie by the hour, eager, alert, at Thornton's
feet, looking up into his face, dwelling upon it, studying it,
following with keenest interest each fleeting expression, every
movement or change of feature. Or, as chance might have it, he
would lie farther away, to the side or rear, watching the outlines
of the man and the occasional movements of his body. And often,
such was the communion in which they lived, the strength of Buck's
gaze would draw John Thornton's head around, and he would return
the gaze, without speech, his heart shining out of his eyes as
Buck's heart shone out.