48 DANGEROUS THOUGHTS country as long as I have, you would know that a native can't be taught to read or write. Myself: Have you ever visited Fort Hare Missionary College? Almost any S.A.G.: Don't talk to me about missionaries. Mysrf/rWefl, I have. I have seen a class of pure blood Bantu students from the Cis-Kei working out differential equations. Almost any S.A.G.: What would you do if a black man raped your sister * As an experimental scientist I know of only one way of finding out whether mixed marriages are advisable. That is to encourage them where we can assure the offspring the same cultural advan- tages as children whose parents belong to the same ethnic group. They seem to be doing this at present in the Soviet Union. To some extent it has been done without noticeably disastrous consequences in the British West Indies, where, according to my negro students from St. Kitts, there is relatively little nonsense about the "instinctive" [sic] social incompatibility alleged to result from the action of tyrosinase. The most successful parental achievement of which I have had a close-up view was the F.I generation of a Swede-Bengalee cross. Of three children the daughter acquitted herself with great credit in the mathematical and economics triposes at Cambridge. A charming la^y, she now has a responsible post at Geneva. The eldest son, a lifelong friend of mine, obtained a double first in the natural sciences triposes. He is an extremely handsome as well as a very congenial person. Unfortunately the youngest son went to Oxford, where he obtained a first in Greats and was permanently incapacitated for lucid statement or realistic judgments about current social ques- tions. I think that his headmaster rather than his parents were to blame for letting so much natural ability go to seed. Aside from the example cited, in the successful mixed marriages* I have known one partner has been a Scot. Maybe this is a portent. For two hundred and fifty years the Scots were busy educating the English. Naturally they now feel equal to the task of educating anybody. Dogged self-assurance of that sort is a necessary prerequisite for one of the partners in a durable