June 28, 1956

Dear Tracy:

Thanks for your comments on the paper. We just got back from a trip
Monday, so Jim ani we had to go over them rather hurriedly to meet the
deadline, but we have made good use of them. I don't think it is profitable
for an author and reviewer to mike detailed post—mortems (which is parhaps
the main justification for maintaining ananymtty), but I hope we will have
a small chance at least to get together ani talk over the whole problem
when you visit us in August.

Some of the stricture of the paper should be helped by putting in

a paragraph numbering scheme (as an experiment) with which one can easily
refer back and forth to the narrative.

fe have considered the experiment you suggested (transductional effects
on phasey variation without allelic substitution), but it is rather difficult
to measure the rates of phase variation in typical diphasic stocks. Iino
has made some progress in this direction recehtly. The issue is also brought
up obliquely in relation to the very sluggish phase variation of certain
stocks, which may be due to a modifier.

I am bowled over by the amount of work you mist do in reviewing mss.
like this, and must confess my own performances in this line are usually
much more superficial. Needless to say (and we have said it before) we are
very grateful to you for the effort.

See you in August,
Sincerely,

od oshua Léderbe rg