Letter from Howard Walter Florey to C H Lack, Institute of Orthopaedics, Brockley Hill, Stanmore Thanks for letter about emigration of leucocytes - is enclosing reprint - refers to paper by Marchesi which carries observations further - unlikely to do more experiments on these lines s Marchesi has returned to USA - if finds someone to continue work, would like to contact Lack about enzymes and inhibitors - must not overestimate what electron microscopes will do. 6 May 1961