I'm a big fan of turtles. I own a small tortoise, for example, and go for walks specifically to see snapper and painted turtles near my Minneapolis home (I don't actually live in Mongolia). And I am a very interested layperson, but not a biologist, zoologist, or herpetologist. I suppose I could best be described as a scientifically literate naturalist. And THAT is who this book is decidedly for, as author Donald Jackson lays out in an apologetic paragraph about how this book might be too technical for those not accustomed to reading science and too simple for actual scientists (which he tries to remedy through copious references to technical source material the scientist can peruse). The problem with compromise can be that you end up satisfying no one, but in this case I think Jackson hit the Goldilocks sweet spot and it was "just right."
It helps that the subject matter is naturally fascinating and even a little charismatic. There is much to talk about with regards to their physiology because of their highly specific adaptations related to staying alive for long periods without breathing oxygen (which includes handling the lactic acid build-up this entails), being neutrally buoyant though structurally dense, respiring without a chest that can expand and contract as ours does, reproduction (he uses a charming bit of doggerel from Ogden Nash on that topic), and other issues.
There is nothing especially "practical" in "Shell," from the standpoint of a guidebook or care-and-feeding book. But "Shell" is a paragon of how to write for people who become intensely curious about a topic for which no decent lay material exists. The writing style is lively and engaging, seasoned with some dry humor, and the book is no longer than it needs to be to cover the most interesting topics in the briskest way. It also demonstrates first-hand what the scientific method is and how it works, which is a valuable contribution to our understanding of "how do we know such and such"?
While giving the book all five stars for overall exceptional quality, I do have at least two quibbles. First, the evolution of the turtle gets fairly short shrift, confined as it is to a few pages early in the book. I realize that this is a book of PHYSIOLOGY and getting bogged down in turtle evolution would have been inappropriate. But physiology can be illuminated by reference to adaptations, and I felt there were some wasted opportunities to say more about the history of some adaptations. It could be, however, that not much is actually known for sure about certain evolutionary pathways, so Jackson decided that "whereof we do not know, we should not speak."
The other thing is a few relatively minor spelling and punctuation errors. In a book from a popular press this would not even merit mention, but my standard for something from Harvard University Press is perfection and nothing less. The most egregious example was a misspelling of an ancient turtle's Latin name. Easy enough to do (those names do look like letter salad often enough), and certainly no spellchecker is likely to catch that sort of mistake, but few things in the book could have been more important than getting all the names and technical nomenclature completely right. As I said, minor and not enough to detract from the quality of work generally--just something I would be happy to see fixed in any subsequent editions.
