In the English language, someone who overeats is called a "pig"; a coward gets labeled a "chicken." If you raise pigs or chickens, you know that these barnyard associations are deftly accurate. Pigs are voracious eaters, chickens are laughable cowards. It all makes perfect sense...

Our recent contest picture of a lye barrel prompted readers to submit a number of great historically-themed shots. Here's one, submitted by Joseph Adams of Rupert, Vermont. OK antique-farm-equipment buffs, what in the woods is this?

As we all know, many mammals have a bone in their penis, called a "baculum." From an evolutionary perspective, this can make copulation more effective (note the strategically curved tip - it's why mating dogs often seem stuck together).

From a human social perspective, the bones give strange credence to the adolescent term "boner," a keystone word in the vocabularies of middle school males everywhere. Parents take heart: your seventh graders use of the term may reveal a somewhat disturbing lack of insight into human anatomy, but on the other hand, it does indicate a rather sophisticated understanding of mammalian reproductive structure.

So. Here's a picture of 5 penis bones from a mink, a raccoon, a porcupine, a fisher, and a coyote. Left to right, match the animal with the baculum.

As one contestant pointed out, this was a hard one. (Sorry, we'll stop.)

Thanks to naturalist/author Mary Holland for sharing this great picture. You can learn more about the natural world by reading Mary's new book: Naturally Curious, available now at www.trafalgarbooks.com or at a favorite bookstore. Also, check out her blog at: http://naturallycuriouswithmaryholland.wordpress.com/