We must confess, then, that if the representation which God gives us in the Supper is true, the internal substance of the sacrament is conjoined with the visible signs; and as the bread is distributed to us by the hand, so the body of Christ is communicated to us in order that we may be made partakers of it. (John Calvin, Short Treatise on the Lord’s Supper, 17)
The interesting thing is that Calvin here deals the presence of Christ in terms of “substance.” Not only that, Calvin speaks of the “internal substance” being “conjoined with the visible signs.” This comes close to consubstantiation, where the substance of Christ is conjoined to the substance of bread and wine. Quite remarkable.
Calvin in the same treatise later goes on to refer to transubstantiation as “the devil’s doctrine”. Here I would say that Calvin is obviously wrong, but it seems that Calvin assumes that the Catholic Church teaches that the substances of bread and wine are “annihilated,” and this is not exactly what the Church teaches.