What does marlow mean he says in paragraph 2 that england “has been one of the dark places of earth?

Having not read the paragraph, I can only help you find the answer.  To say that someplace is dark, it means terrible things have happened there.  As you read through the paragraph, what bad things have happened in England that would lead one to believe it is a dark place?  This goes beyond just being physically dark outside.  Are people depressed?  Is the weather constantly rainy, making it gloomy and dark?  Was there a murder or terrible illness?  

the excerpt from chapter 2 of "animal farm", by george orwell that is an example of foreshadowing is "these three (snowball, napoleon, and squealer) had elaborated old major's teachings into a complete system of thought to which they gave the name of animalism." animal farm is an allegory of how czarist russia developed into communist russia with all its corruption. old major's teachings represent marx's theories turned into communism, animalism, by the three pigs. this foreshadows the oppression and corruption that will follow this revolt.