There appears also to have been an allusion in this figure to the ordinance of baptism. “We are little fishes,” says Tertullian, “in Christ our great fish. For we are born in water, and can only be saved by continuing therein,”[410] that is, through the spiritual grace of which baptism is the visible sign. “This sign,” says Clement, “will prevent men from forgetting their origin.” “He (that is, Christ) is that fish,” says Optatus, “which in baptism descends in answer to prayer into the baptismal font, so that what was before water is now called, from the fish, (_a pisce_,) _piscina_.”[411] Even the mythical 254 fish mentioned in the apocryphal book of Tobit,[412] occasional pictures of which occur in the Catacombs, is interpreted by some of the Fathers as typifying Our Lord. “That fish which came alive out of the river to Tobias,” says Augustine, “whose heart, (liver,) consumed by passion, put the demon to flight, was Christ.”[413] This sacred sign was also regarded as an emblem of the sufferings of Our Lord and the benefits of his atonement. “The Saviour, the Son of God,” says Prosper of Aquitania, “is a fish prepared in his passion, by whose interior remedies we are daily enlightened and fed.”[414] “ΙΧΘΥΣ is the mystical name of Christ,” says Augustine, “because he descended alive into the depths of this mortal life as into the abyss of waters.”[415] “The fish in whose mouth was the coin paid as the tribute money,” says Jerome, “was Christ, at the cost of whose blood all sinners were redeemed.” Origen merely speaks of him as “figuratively called the fish.”[416] “Thus this symbol became,” says Dr. Northcote, “a sacred _tessera_, embodying with wonderful brevity and distinctness a complete abridgment of the creed--a profession 255 of faith, as it were, both in the two natures and unity of person, and in the redemptorial office, of Our Blessed Lord.”[417] [Illustration: Fig. 50.--Symbolical Fish.]