When it came near he noticed that it had a penny in its mouth.

A cat's-meat barrow was standing by the kerb, and for a moment, as he passed it, the dog hesitated.
But his nobler nature asserted itself, and, walking straight up to the hospital railings, and raising himself upon his hind legs, he dropped his penny into the contribution box.
MacShaughnassy was much affected by this story.

He said it showed such a beautiful trait in the dog's character.

The animal was a poor outcast, vagrant thing, that had perhaps never possessed a penny before in all its life, and might never have another.

He said that dog's penny seemed to him to be a greater gift than the biggest cheque that the wealthiest patron ever signed.
The other three were very eager now to get to work on the novel, but I did not quite see the fairness of this.