INDIANA UNIVERSITY

BLOOMINGTON, INDIANA

November 5, 1953

Dr, Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison 6, Wisconsin

Dear Josh:

In view of your comments, Iwent back to my Bellagio paper and can
see that my exposition on pp. 7 and 13ff was not sufficiently clear.
I eve already submitted this as my manuscript for publication but,
in view of your suggestions, I have made some changes in an attempt
to clarify it. I am sending you a copy with these changes. If you
think this will do, and have no further comments, I'll try to get the
revision substituted for the original. Since I have already somewhat
exceeded my space assignment, I don't think I can ask to have tables
of the data included. I hope later to publish a full paper on d59
and other clones, including tables, photographs, and drawings, I
showed some of the tables and photos at Bellagio, Do you think it is
so desirable to have them in this paper that I should still try to get
them in?

In case my modified manuscript remains unclear, I'll add here some
further comments for you. The section on page 7 refers to the first
meiosis after the norm] haploid micronucleus was introduced into d59,
i.e,, at the first autogamy following the conjugation with the normal
mate. When I say here that micronuclear behavior and survival is
normal, I refer only to the passage of a reduced nucleus into the paroral
cone, its survival, and its subsequent division. In the one exceptional
clone, I refer to cytologic examination of* 64 autogamous imlividuals

at the stage when a micronucleus should be in the cone or soon there-
after; in more than 40 per cent of these, no micronuclei could be found.

The section on pp. 12-16 refers to a later stage, the stage when the

products of division of the surviving nucleus should differentiate into

two micronuclei and two macromuclei. The statement that nuclear

development is usually abnorml means that usually one does not find
at this stage two micronuclei and two macronuclei, Moreover, this

section deals first with nuclear development immediately after intro-

duction of the haploid nucleus from the normal mate; and then with the
corresponding stage at the next autogamy.

Your comment about macronuclear material is of course well taken in
certain connections. I don't see how it could be involved in the part
discussed om page 7 unless there is some as yet unknown way in which
macronuclear material persists after it has disappeared from view.
(About twenty years ago I thought I saw macronuclear anlagen that had