Book Reviews : The Circle of Discrimination--An Economic and Social Study of the Black Man in New York. By HERMAN D. BLOCH (New York, New York University Press; London, University of London Press, 1969). xiii + 274 pp. $7{middle dot}95. Scottsboro--A Tragedy of the American South. By DAN T. CARTER (Baton Rouge, Louisiana State University Press, 1969). xiii + 431 pp. $10{middle dot}00