这本来是个GRE的阅读句子，在杨鹏那本阅读练习的书上看到的，但有一句语法看不明白，还望老师赐教。
Such variations in size, shape, chemistry, conduction speed, excitation threshold, and the like as had been demonstrated in nerve cells remained negligible in significance for any possible correlation with the manifold dimensions of mental experience.
这句话书里面将such as的组合讲解为such thing as something，我的问题就是本句话as后面仿佛不是something而是一个句子。请问这句话的such as到底该如何理解？as后面是定语从句as （variations that） had been demonstrated 的省略形式吗？还请各位赐教！
依据传统语法，当先行词被such修饰时，定语从句有关系代词引导。所以从传统语法角度剖析，as为关系代词，指代前面的以variations为中心词的名词词组，并在定语从句用途作主语。
