And one thing kept bothering me, and that's, when they're functioning, penises don't wiggle.

You wouldn't think that skeletons and penises have very much to do with one another.

Most cats have serrations on their penises and apparently it's a painful ordeal for the female.

Now the penis isn't actually required for internal fertiliztion, but when internal fertilization evolves, penises often follow.

And eventually, it just makes them stop playing with it, or they draw penises and things like that.

And eventually, it just makes them stop playing with it, or draw, you know, they draw penises and things like that.

I did have to explain it to my nine year old late last week penises are structures that transfer sperm from one individual to another.

And this is true both of my recent project on sex differences in the brain, and my more mature work on the anatomy and function of penises.