May 6, 1950.
Dear Dr. Hollaender:
I regret to have to write you that I will probably have to withdraw from the proposed volume on radiobiology, in which you had kindly asked me to participate, with a chapter on ultrviolet effects on bacteria.  I shall be leaving for the summer in about six weeks, and I hve too much else to do in that time to be able to think about this chapter.  I hope that you can find a suitable alternative author, or that the organization of the volume can be appropriately shifted.  In any event, please accept my apologies for any inconvenience that this may cause, but I can see no way to meet the obligation by the deadline.
Yours sincerely,
Joshua Lederberg.