(Stockholm, 1954). 8vo. Stapled without wrappers (as issued). Offprint from ""Acta Physiologica Scandinavica"" 1954, Vol. 32, Fasc. 1.
Offprint of Ottesen's paper in which he discovered that while the half-life of most B cells is 24 hours or less, long-lived T and B cells live for a year or more.