June 11, 1928
Dear Dr. Sabin:
Miss Randolph has not been very successful in the staining of the chick embryos.  Enclosed find an account of her method.  The acetone has usually been excluded; it was tried to see whether it would improve the sections.  The sections were fixed in Bouin's fluid for one-half to one hour, according to the formula you give in your paper ("Studies of the Origin of Blood Vessels and of Red Blood Corpuscles as Seen in the Living Blastoderm of Chick during the Second Day of Incubation").  Would you please give any suggestions you might think helpful, especially with regard to the length of time in each fluid?  The sections are not clear but have a tendency to be "muddy."  Miss Randolph, who is excellent in this kind of work, has been trying several combinations and different solutions, without entirely succeeding, and any aid you might give will be greatly appreciated.  We are working away with the chick embryos and hope to have some interesting results in the very near future.  I have had rather bad luck with the fertility of our eggs at this time of year, as most poultrymen have "torn up their pens."
Didn't you and Dr. Doan write an article on the variation of red blood cells in the normal person?  I have tried to find the article but have not succeeded.
With best wishes,
Sincerely yours,
Gulli Lindh Muller.