"'In point of fact our ascendancy has been so complete that we are rarely called upon to kill wolves nowadays - in fact, most of us have quite forgotten what it means to have to fight in a personal way against another species. But, when the need arises we have no compunction in fully supporting those who slay the threat whether it is from wolves, insects, bacteria, or filterable viruses; we give no quarter, and certainly expect no pardon.'"