It's not difficult to imagine the reasons driving this process. Doctrinal and ecclesiastical differences cause churches to part company, and once a precedent is set, then every subsequent dispute is more likely to have the same result. Occasionally two groups will find they have enough common ground to merge, but this is much more difficult than splitting, and so over time, the number of splinter groups goes up and up.
I offer this as a comment on the possible futures now facing the Church of England. After the General Synod affirmed its will to see women bishops in the near future, some opponents are tempted to go it alone, perhaps to form their own group of "continuing Anglican churches", "free and evangelical Church of England", or some similarly defiant description. It's a strong temptation, one which I feel myself, not over women in the episcopate, but just because it sounds so enticing. Wouldn't it be great to be part of something where we could all be like-minded, and not have to rub up against all those others with their strange views on, well, more or less everything, really.
To anyone thinking like that, I say - this diagram shows the future if we go down that route. One split begets another, and another, and another. It's obvious, really. If you start forming a church on the basis that all should agree, you begin a chain reaction. Every disagreement becomes a schism, a process that has no necessary end, until the point where there's only you left, and nobody to disagree with any more.
Some people may not be at all worried by that possibility. It may be that some churches will leave, become independent, and flourish. But I prefer to stay put. For all its flaws, the Church of England continues to thrive (yes, I did say that without irony) despite the disparities it contains. To say it has a unity in diversity might be pushing it. But there is a kind of strength in diversity that would be lost in a smaller, purer church. Let's soldier on together. It can be hard work, but it's our way. And it gives Presbyterians something to laugh at.