The Bigelow-Wallis and Warren-Kaula watercolor collection is a set of 189 watercolor paintings commissioned by Harvard professor of surgery Henry Jacob Bigelow from lithographer Oscar Wallis between 1849 and 1854. There are a lot of weird and gross images in this collection worth checking out, but my favorites are the skulls – gorgeous, subtly colored and undeniably deformed and diseased. Check out the skull collection below, plus make sure to take a look at some of the other anatomical paintings that are a part of the exhibit.