Where did the term "China Rails" come from

I read the term in books with it referencing the long thin front and rear wall of the block ends. How it came to be for sure, IDK, it does bare a resemblance to the Great Wall of China. So I bridged the gap like that.

Older folks have “Chinaware” of referred to as simply “China” to eat on. Normally an Ornate and beautifully decorated plates that are fragile. On an engine block, the rear walls would be considered the weak spot of the block when handling/machining it.