Read Darwin's Mind: His Annotated Library is Now Online

Charles Darwin had 1,480 books in his personal library. What was he thinking as he read through them? Now you can find out for yourself. The Biodiversity Heritage Library scanned 300 of them so far, many of which have Darwin’s comments scribbled in the margins.

In addition to traveling the world to observe natural history, Darwin read extensively about the subject. Both activities helped him develop his theory of evolution by natural selection. To track Darwin’s thoughts, the library indexed his annotations by topic, so you can search the digitized pages with ease. And the commentary covers a large range. His collection contains many books about animals including sheep, horses, snakes, and dogs. He also had books about geology, physiology, fruits, plants, and even blushing.

Here is a sample of the books he owned about birds:
-The new and complete pigeon-fancier: or, modern treatise on domestic pigeons (By Daniel Girton);
-Ornamental and domestic poultry: their history and management (By Edmund Saul Dixon); and
-A history of British birds (By William Yarrell).

Darwin’s incredible breadth of knowledge about a wide variety of animals is evident within some of his annotations. For example, in An introduction to the Trochilidae, or family of humming-birds, the author (John Gould), writes, “…I believe colour is seldom given without the intention of its being exhibited, there is doubtless something peculiar in the economy of these birds.” Darwin writes at the top of the page: “Bates Butterflies. when under side displayed this is beautiful.”

Annotations that reveal the most about Darwin’s own thoughts about evolution and natural selection are in books by other theorists of the time.

In some, he found additional evidence to support his theories: Next to a section on parasites in one book, Darwin writes, “Like diseases proof of relation of man to other animals” (The text in the book reads, “A small number only of intestinal worms occur in different genera of animals. Thus the Taenia of man is peculiar to him; on the contrary, the Distoma Hepaticum, the hydatid of the liver, seems to be common to man, the hare, cow, camel, deer, horse, and hog…”).

Others frustrated him with their lack of explanation or data to support assertions: The Catholic convert St. George Jackson Mivart wrote a book entitled On the genesis of species in response to Darwin’s thesis in 1871. In the book Mivart writes, “In the strictest and highest sense "creation" is the absolute origination of any thing by God without pre-existing means or material, and is a supernatural act,” to which Darwin comments, “for scientific purpposes Mr Mivarts belief that sudden change… seems to me no gain over the old belief of separte creation: Of course it may be true, but will be most difficult to prove.” He also draws a microscope lens and eye here.

And his comments aren’t without humor. Alongside one passage in The anatomy and philosophy of expression (By Charles Bell), Darwin scrawls, “I suspect he never dissected monkey.” Darwin was a master observer; you can’t fool him.

See also:
Star of the Show: An orchid in Darwin's Garden at the New York Botanical Garden
Galapagos Now: Can the Galapagos ecosystem survive?
From One Pioneer to Another: James Watson visits the Galápagos (interview)