https://www.vice.com/en_us/article/5dmwbd/150k-nature-illustrations-spanning-hundreds-of-years-are-now-free-online

The Biodiversity Heritage Library (BHL) has uploaded more than 150,000 images of biological sketches, some dating back to the 15th century, onto the internet. They’re all in the public domain, and free for anyone who wants them.

The images are pulled from journals, research material, and libraries, altogether more than 55 million pages of literature. BHL is “the world’s largest open access digital library for biodiversity literature and archives,” according to its website. On top of public domain content, BHL also works with rights holders to get permission to make copyrighted materials available under a Creative Commons license.