St. Justin was born about 110 A.D. in Palestine. He was converted to Christianity around 135 and turned his skills as a philosopher to a defense of the Faith. In the year 150 he wrote his great Apology. Although he was not an outstanding writer (his periodic Greek style tends to use what we would call "run-on" sentences), the work is of great interest because we find in it our first extant description of the Mass as it was celebrated in Rome in the second century.

(65)... And when the one who is presiding has given thanks, and all the people have cried out, those whom we call deacons give the bread and wine and water over which the thanksgiving was made [lit., "the eucharistisized bread and wine and water"] to be received by each of those present, and then they carry it to those who are absent.

(66) This food we call Eucharist, which no one is allowed to share except the one who believes that our teaching is true, and who has been washed with the washing that is for the remission of sins, and unto regeneration, and so lives as Christ has handed down. For we do not receive these as common bread and common drink; but just as Jesus Christ our Savior, having been made flesh by the word of God, had both flesh and blood for our salvation, so likewise have we learned that the food over which thanks has been given by the prayer of the word which comes from him, and by which our blood and flesh are nourished through a change [Gk. kata metabolen], is the Flesh and Blood of the same incarnate Jesus (The First Apology).

The Hidden Manna: A Theology Of The Eucharist
Rev. James T. O'Connor