Caius was under the impression that his father could have refused him the necessary outfit of medical stores for this expedition, but that was not the way old Simpson looked at it.
"If he must, he must," he said to his wife angrily, gloomily, for his own opinion in the matter had changed little; but to Caius he gave his consent, and all the money he needed, and did not, except at first, express his disapproval, so that Caius took the less pains to argue the matter with him.
It was only at the last, when Caius had fairly set out on his journey, and, having said good-bye, looked back to see his father stand at the gate of his own fields, that the attitude of the stalwart form and gray head gave him his first real insight into the pain the parting had cost--into the strong, sad disapproval which in the father's mind lay behind the nominal consent.

Caius saw it then, or, at least, he saw enough of it to feel a sharp pang of regret and self-reproach.

He felt himself to be an unworthy son, and to have wronged the best of fathers.
Whether he was doing right or wrong in proceeding upon his mission he did not know.

So in this mind he set sail..