I love Stephen Jay Gould. I really do. I'd probably love him more if he hadn't died so early. He takes complicated subject matter and writes about it in such a way that it seems like the simplest thing you've ever read. This book is a collection of essays about natural history, just like most of his books are. This is the first collection of his essays that I've read (I've only read two other books of his, which is absolutely shocking!).
There's not really much you can say about his work - it's easiest just to say: read it yourself. Not only does he say everything far better than I ever could, it's totally worth it and you could never regret reading anything he's written (and if you could, then I don't really want to know you).