E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
In the examinations for degrees in the University of Cambridge it was customary, at the beginning of the January term, to hold Acts, and the candidates for the Bachelors degree were called Questionists. They were examined by a moderator, and afterwards the fathers of other colleges questioned them for three hoursi.e. one whole hour and parts of two others. (I began my Act about a quarter to eleven and finished about half-past one.) It was held altogether in Latin, and the words of dismissal uttered by the Regius Professor indicated what class you would be placed in, or whether the respondent was plucked, in which case the words were simply Descendas domine.