Dr. Fredrickson 
Page two 
can transfer to the plant cell. Even when the whole Ti plasmid 
is put into E. coli the strain cannot incite plant tumors. 
The possibility of creating a super-pathogen by our cloning 
experiments thus appears nil. 
I hope that these facts will be considered and that the con- 
tainment level for cloning Ti plasmid fragments will be set 
at a reasonable and clear position before the revised Guide- 
lines are accepted. I thank you for the opportunity of 
stating our dilemma publicly. It was a pleasure and a privilege 
to participate in your committee meeting. 
Sincerely yours, 
Mary-Dell Chilton 
Research Associate Professor 
Department of Microbiology & Immunology 
SC42 
[Appendix A— 149] 
