STRANGEWAYS RESEARCH LABORATORY,
WORT’S CAUSEWAY,
CAMBRIDGE.

February 7th,1953

Dr Joshua Lederberg
Dept.of Genetics
University of Wiskonsin

Dear Dr Lederberg,

Thank you very much for your interesting reprints
from which I learned a great deal. To show you how I
appreciate your review I should like to draw your atten-
tion to a few minor defaults, hoping you will accept them
as dictated by good will.

The field you review in "Cell Genetics and Hereditary
Symbiosis" is so vast that you could not possibly peruse
every publication, particularly older ones, and thus I
am not surprised that you made use of Lwoff's writings.
They may be called stimulating and even brilliant but
certainly not objective, and you should not look too much
through his spectacles but read him critically. The para-
graphs on Euglena on pp. 406 and 407 give not a true pic-
ture of the situation and do not sufficiently integrate
the various results, nor do they differentiate between
findings and hypotheses. Perhaps you would do me the favour
and read my papers again, also that of 1937 (Beitrage zur
Physiologie saprotropher Algen und Flagellaten III, Planta
27 61,).

To my knowledge no other alga has been "bleached" so far
by streptomycin than Euglena gracilis. Chlorogonium looks
almost colourless in every young thriving culture in a rich
medium; - nor are chromatophores of Euglena gracilis de-
stroyed by rich feeding. Not the "fate of the pyrenoid" is
controversial but the existence of chromatophores where
none can be demonstrated. Temperature treatment causes
destruction of chromatophores as does streptomycin. That
is essential! Perhaps you find the time to inspect pp.
213 - 216 in Lwoff's book of 1943. It's all wrong!

In your treatment of Paramaecium bursaria as at other
places you give several authors in one pair of brackets,
so that the reader does not know to whom the various fin-
dings are attributable.

lam sure you can easily mend these small mistakes in
your next review, and then they will be still more useful.
We need people who take such troubles.

Some more reprints will be send under separate cover.

Yours sincerely
co

E.G.Pringsheim