Jerome Zanchius (1516-1590) on the Succession of Bishops
Girolamo Zanchi (or Jerome Zanchius) was an Italian Protestant Reformation clergyman and educator. (Check profile at Wikipedia, Theopedia). Following excerpts are from Chapter 24 of his book, Confession of the Christian Religion.
True Churches of Christ
...those churches we acknowledge for the true churches of Christ in which first the pure doctrine of the gospel is preached, heard, and allowed of, and that so allowed of that there is no place nor hearing for the contrary (Matt. 28:19-20)....
The Church as Apostolic
...we acknowledge that from a perpetual succession of bishops in some church, I say not any manner of succession, but such a one as hath had joined also unto it, a continuance of the apostles' doctrine, it may rightly be showed that that church is apostolical [apostolic]. Such a one as was once the Church of Rome, and the succession of the bishops thereof, even to the time of Ireneus, Tertullian, Cyprian, and some other, so that they were wont not without reason to appeal unto it, and cite before it, and such other of the fathers, the heretics of their times. But indeed as we do acknowledge and confess with Tertullian and other of the fathers that those churches are to be acknowledged to be truly apostolical [apostolic], in which the apostles' doctrine, with the discipline of Christ and lawful administration of the sacraments, is kept pure, though the same have not been planted by the apostles, nor have had a perpetual succession of bishops, even from the apostles' time.
Possibility that A Church Ceases From Being Apostolic
...the churches which were planted and watered by the apostles, although they can show a succession of bishops continual and without interruption, yet if with the succession of bishops they cannot also show a continuance of the doctrine of Christ and His apostles, we will grant that they have been Christian and apostolical [apostolic] churches, but now we cannot acknowledge them for such. For as the hood (as the proverb saith) makes not the monk, but his godly and holy life, so neither do bishops, but the doctrine of Christ and Christian religion, make the Church of Christ.