In Chapter 7 of "Call of the Wild", what was the wolf's reaction to Buck?

The wolf's first reaction was to flee when he saw Buck.  He was "suspicious and afraid; for Buck made three of him in weight, while his head barely reached Buck's shoulder".  Buck, wanting only companionship, chased the wolf until he cornered the wild creature, who "whirled about...snarling and bristling, clipping his teeth together in a continuous and rapid succession of snaps".  Buck did not attack, but instead "circled him about and hedged him in with friendly advances". 

This sequence was repeated several times, with the wolf alternately running away, being cornered, and running again.  The wolf was "in poor condition, or Buck could not so easily have overtaken him" each time.  Finally, seeing that Buck did not intend to harm him, the wolf sniffed noses with him, and the two played together for awhile.  The wolf then took off, encouraging Buck to follow, and Buck, "wildly glad...(ran) by the side of his wood brother toward the place from where the call (of the wild) surely came".  Even as he felt the call growing within him, however, Buck remembered John Thornton, and, torn, turned around and walked slowly back to the camp, leaving his brother behind (Chapter 7).