Dr Sewell Champe,
Purdue University,
Department of Biological Sciences,
Lafayette,
Indiana 47907,
U.S.A.

Dear Sewell,

2nd November 1966.

  I enclose a copy of our paper.   From its weight alone you can see
why it has taken us ao long to produce it,
comments at this point.              I think I need only make two
anomalous mapping of    PLrst, we have not rJaid any-thing in it about the
          1X:58 we thought we could put this in proof when

things are a little clearer.   Second, we have removed from our earlier
draft some of our remarks about the identity of the barriers as we plan to
publish this in a separate paper.  It now aeema almost certain that X655
together with barriers bs and b6 are UGA, and we hope to know veq shortly
whether b2 is the aame,  We are also going to try to put an amber in place
of barrier b6 and see if this will produce minutes when combined with two
suitable plus mutants,  If it does not this will suggest that the productic
of minutes does not deueixd on chain termination.  .Our present case is that

there is no tRF!A for UGA.

How are you getting on in your search for the rII protein?-

Enclosure

KHX. Crick,