August 4, 1955

Dy. Robert Briggs
ankenaug Institute
iladalphia 11, Pa.

Dear Bob:

Thank you for your letter. I hope you de have some chance to go back
te use the toluidine blue technique. ile may see what happens to transduced
fragments (inside phage) with 4t.

Since my last letter, I've talked the problem over with Dr. Crow, and
one of his dtudents is interested to try the effect on bees, which are use~
ful mterfal because of the development of artificial insemination techniques,
and the haploid-daéploid sex determination. Have you an extra copy of two
of that article in JGP?

I thought you might be interested sam go see how I brought the Salmonella
phase variation story into our ms. for the Amherst symposium (which was Largely
at your instigation)— the draft form Ska is enclosed.

Yours sincerely,

Joshua Laderberg

Ref PM Te tte