The late linguist M.A.K. Halliday described the last paragraph of Darwin’s Origin of Species, with its description of a tangled bank, as one of the most remarkable paragraphs in the whole of literature. Yet it appears marred by an obvious grammatical mistake. In this article, we seek to show that the apparent mistake is actually the vestige of a now extinct form of paragraph in which the structure we now reserve for a single sentence could be extended over a whole paragraph or even many paragraphs. We first zoom out to show that the final sentence makes sense in the context of the paragraph as a whole, and then zoom out again to show that the modern paragraph itself is still a work in progress. Finally, we use a comparison between English and Farsi to try to show that all such grammatical choices mediate between humans and their environment. This relationship too is a work in progress in which the grammar of a language has an important role to play.

已故语言学家麦·哈里迪（MAK Halliday）描述了达尔文的《物种起源》的最后一段，其中描述了缠结的银行，是整个文学中最引人注目的段落之一。然而，它似乎因明显的语法错误而受损。在本文中，我们试图证明明显的错误实际上是现在已经绝迹的段落的遗迹，在该段落中，我们现在为单个句子保留的结构可以扩展到整个段落甚至许多段落。我们首先缩小以显示最后一个句子在整个段落的上下文中是有意义的，然后再次缩小以显示现代段落本身仍在进行中。最后，我们使用英语和波斯语之间的比较来尝试表明，所有这些语法选择都在人类及其环境之间进行调节。