Henry Walter Bates was one of the four British pioneers of biology, the others being, Alfred Russel Wallace, Richard Spruce, and – of course – Charles Darwin.

Bates and Wallace, both in their mid-twenties at the time, left England in 1842 to explore and collect insects in the Amazon basin. Eleven years later Bates returned to England with a collection of 14,712 species, eight thousand of which were new to science. This was not comfortable work.

I was worst off in the first year, 1850, when twelve months elapsed without letters or remittances. Towards the end of this time my clothes had worn to rags; I was barefoot, a great inconvenience in tropical forests … the contemplation of Nature alone is not sufficient to fill the human heart and mind.

Bates was a true adventurer, and much of the narrative reads like a treasure hunt. His excitement is contagious: while staying in the town that would later be known as Belem, he found seven hundred species of butterfly within an hour’s walk of the town, “whilst the total number found in the British Islands does not exceed sixty-six.”

During his sojourn in the jungle, Bates developed his theory of mimicry, in which non-poisonous animals mimic the bright warning colors of poisonous animals – evidence of natural selection – which supported Darwin and Wallace’s theory of evolution.

Back in England, Darwin urged Bates to write a memoir of his years in the Amazon:

It is the best work of Natural History Travels ever published in England. Your style seems to me admirable. It is a grand book, and whether or not it sells quickly, it will last.

It has.