Who played Dr Muller's assistant?

I met and spent some time with Bramwell Fletcher many years ago when he was touring in a one-man show about George Bernard Shaw.(According to Fletcher, who had known Shaw, he was the only actor approved by Shaw's estate to play him). Anyway, I found Fletcher (and his wife, playwright Lael Tucker Wertenbaker)to be charming and interesting. He told me enjoyed his days in Hollywood and being part of the "British Colony" there. He was under contract to Sam Goldwyn and was also loaned out to other studios. He told some great stories about the people he met (William Randolph Hearst and Marion Davies at San Simeon, Ronald Colman, David Niven, etc.). A very nice man and a distinguished stage actor. But he will mostly be remembered as the assistant who goes mad in The Mummy.