Check out this drawing, on the back of a page from the original manuscript of Darwin's On the Origin of Species. The sheet will go on public display Monday as part of "A Voyage Round the World," a new exhibit at Cambridge University Library that will explore Darwin's experiences on the Beagle. (The library is reported to have another 23 sheets from the manuscript, and it's believed there are about 10 more out there.)
But there seems to be a bit of confusion over who drew the picture and whether the drawing, which library staff is said to be calling the "Battle of Vegetables," has been on display before. According to the Telegraph:

It is not known which of Darwin's 10 children drew the picture but it is thought the child would have been between eight and 10 years old.

A spokesman at Cambridge University said it was believed that this is the very first time the drawing had been put on display to the public.

Contrary to the stereotype of the dispassionate scientist, however, Darwin was a man to whom family and friends mattered profoundly, and many poignant objects in the exhibition remind us of his humanity. On the back of a rare manuscript page of the Origin, we find a drawing, "The Battle of the Fruit and Vegetable Soldiers," by Darwin's young son Francis.

There are just thirty or so of these original sheets in existence and the vast majority have a child's drawing on the back. It's quite amazing to think these priceless historical exhibits have only survived because of a child's drawings on the back. It demonstrates the importance of his family and brings it home that he surrounded himself with family, and friends, as he worked.