I probably was the source of Dr. Elliott's "definite opinion" that Dr. Avery and Dr. Griffith never met or corresponded.
I can only say that this certainly has always been my impression and was doubtless casually stated around the laboratory.
Dr. Avery was not a prolific correspondent and usually wrote letters only if he had to. Of course, Dr. Griffith died in 1941,
before Dr. Avery and his group had the definitive work on the pneumococcus DNA published in 1944. Dr. Avery was a perfectionist
and very careful about speaking prematurely of work in progress.
It is always hard to unearth this sort of information at a later date. It did not seem important, only natural, at the time.