November 25, 1949.

Dr. D. M. Bonner,
Osborn Botanical Lab.,
Yale University,
New Haven, Connecticut.

Dear Dave:

Thanks for your very friendly letter. The serological results
that you mentioned are very exciting indeed. I don't quite under-
stand how the enzyme-antibody complex can be pusmmtptial precipitable
without altering fats activity, unless you are using conditions that
would detect one one complexes.

I have always found minimal amounts of galactosidase in K~l2 (and
in Y-53) grown on glucose, but the amounts are less than 1/2 % of
the fully adapted value, and can only be detected after "activation"
by benzene treatment or drying of the cells. I found drying to be
a superior method of preparing cells for extraction, and, of course,
mach more convenient and flexible than grinding— but for your pur-
poses, you may have spsoial requiregents.

Just so long as weaahels know what the other is doing, I don't think
any discomfiture should arise from our mutual interests. But I hope you
will wear with me in my concern over the remote possibilities. See
you in New York.

Sincerely,