That book has a preface, not a foreword.

那本书有序文, 有言。

He gave a rather disjointed account of his experience in the jungle.

"在谈到他在热带丛林里经历时,他话言不对后语。"

The preface is complete in itself.

这言本身就是完整。

The introduction is mainly about the definition of eponym, and emphasizing its development and synchrony with language.

言要是名祖名词定义，阐述名祖名词和存在现状，并强调了名祖名词始终与语言共时。