Apart from the hostile influence of man, the organic and inorganic world are, as I have remarked, bound together by suchmutual relations and adaptations as secure, if not the absolute permanence and equilibrium of both, a long continuance of the established conditions of each at any given time and place, or at least, a very slow and gradual succession of changes in those conditions.

主句：Apart from the hostile influence of man, the organic and inorganic world are, as I have remarked, bound together by suchmutual relations and adaptations as secure

【分析】主干部分：the organic and inorganic world are bound together by such mutual relations and adaptations as secure

as secure：按传统语法分析是定语从句。先行词为 relations and adaptations，之所以用 as 作关系代词，是因为先行词有 such 修饰。as 在从句中作主语，secure 是动词作谓语，不可能是形容词。

条件从句：if not the absolute permanence and equilibrium of both, a long continuance of the established conditions of each at any given time and place, or at least, a very slow and gradual succession of changes in those conditions.

【分析】if 之后省略了与主句相同的主语和 be 动词。补充完整为：if they are not the absolute permanence....，they 指前文的 the organic and inorganic world 。