"Most Christian traditions also teach that Jesus is present in the Eucharist in some special way, though they disagree about the mode, the locus, and the time of that presence" (Encyclopaedia Britannica Online).
catho.org
Canon 1. A misprint in this source gives "transubstantiatio" in place of "transubstantiatis" of the original: "Iesus Christus, cuius corpus et sanguis in sacramento altaris sub speciebus panis et vini veraciter continentur, transsubstantiatis pane in corpus, et vino in sanguinem potestate divina" (Denzinger 8020.
ccel.org
There is then brought to the president of the brethren bread and a cup of wine mixed with water; and he taking them, gives praise and glory to the Father of the universe, through the name of the Son and of the Holy Ghost, and offers thanks at considerable length for our being counted worthy to receive these things at His hands. And when he has concluded the prayers and thanksgivings, all the people present express their assent by saying Amen. This word Amen answers in the Hebrew language to γένοιτο [so be it]. And when the president has given thanks, and all the people have expressed their assent, those who are called by us deacons give to each of those present to partake of the bread and wine mixed with water over which the thanksgiving was pronounced, and to those who are absent they carry away a portion. And this food is called among us Εὐχαριστία [the Eucharist], of which no one is allowed to partake but the man who believes that the things which we teach are true, and who has been washed with the washing that is for the remission of sins, and unto regeneration, and who is so living as Christ has enjoined. For not as common bread and common drink do we receive these; but in like manner as Jesus Christ our Saviour, having been made flesh by the Word of God, had both flesh and blood for our salvation, so likewise have we been taught that the food which is blessed by the prayer of His word, and from which our blood and flesh by transmutation are nourished, is the flesh and blood of that Jesus who was made flesh. For the apostles in the memoirs composed by them, which are called Gospels, have thus delivered unto us what was enjoined upon them; that Jesus took bread, and when He had given thanks, said, "This do ye in remembrance of Me, this is My body"; and that, after the same manner, having taken the cup and given thanks, He said, "This is My blood"; and gave it to them alone. Which the wicked devils have imitated in the mysteries of Mithras, commanding the same thing to be done. For, that bread and a cup of water are placed with certain incantations in the mystic rites of one who is being initiated, you either know or can learn. ... And on the day called Sunday, all who live in cities or in the country gather together to one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits; then, when the reader has ceased, the president verbally instructs, and exhorts to the imitation of these good things. Then we all rise together and pray, and, as we before said, when our prayer is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings, according to his ability and the people assent, saying Amen; and there is a distribution to each, and a participation of that over which thanks have been given, and to those who are absent a portion is sent by the deacons. First Apology, 65-67
earlychristianwritings.com
" ... (t)he eucharist is the flesh of our Saviour Jesus Christ, which flesh suffered for our sins, and which in His loving-kindness the Father raised up. ... Let that eucharist alone be considered valid which is under the bishop or him to whom he commits it. ... It is not lawful apart from the bishop either to baptize, or to hold a love-feast. But whatsoever he approves, that also is well-pleasing to God, that everything which you do may be secure and valid." Letter to the Smyrnaeans, 6, 8 "Give heed to keep one Eucharist. For there is one flesh of our Lord Jesus Christ, and one cup unto union with His blood. There is one altar, as there is one bishop, together with the presbytery and deacons, my fellow-servants; that whatsoever you do, you may do according unto God."Letter to the Philadelphians, 4
fordham.edu
Canon 1. A misprint in this source gives "transubstantiatio" in place of "transubstantiatis" of the original: "Iesus Christus, cuius corpus et sanguis in sacramento altaris sub speciebus panis et vini veraciter continentur, transsubstantiatis pane in corpus, et vino in sanguinem potestate divina" (Denzinger 8020.
For example, Roman Catholics, Eastern Orthodox, Oriental Orthodox, "Anglo-Catholic" Anglicans, Old Catholics; and cf. the presentation of the Eucharist as a sacrament in the Baptism, Eucharist and Ministry documentபரணிடப்பட்டது 2008-07-09 at the வந்தவழி இயந்திரம் of the World Council of Churches
For example, Roman Catholics, Eastern Orthodox, Oriental Orthodox, "Anglo-Catholic" Anglicans, Old Catholics; and cf. the presentation of the Eucharist as a sacrament in the Baptism, Eucharist and Ministry documentபரணிடப்பட்டது 2008-07-09 at the வந்தவழி இயந்திரம் of the World Council of Churches