One can live in the shadow of an idea
without grasping it.
—Elizabeth Bowen
Our interest in the size of things is entrenched in the human psyche. It reveals itself in literature from Gulliver’s Travels, to the Grimms’ fairy tales, to Alice in Wonderland. We see it in our daily thoughts of our growing children, of the people who are around us, of our pets, of the fish we catch, of the portions of the food we are served, of the clothes we buy—are you small, medium, or large?—and one could go on and on. There is hardly anything we observe in daily life that we, either consciously or unconsciously, do not take measure of its size. We love to measure everything with rulers and scales and clocks.
I began to think of the matter of biological size years ago when I first read that glorious chapter in D’Arcy Wentworth Thompson’s On Growth and Form called “On Magnitude.” It is a model of insight, erudition, and beautiful prose. He showed me that size and shape are indeed interrelated and that the reason that this is so is a matter of physics that underlies the biology. From this initial inspiration there slowly grew inside me the feeling that there was a hidden other dimension of the subject that was eluding me. That inner feeling persisted for many years, and slowly something began to take shape. I am finally putting it all together in this book—I feel as though those shadowy thoughts have erupted through the surface.
This book is a summary of those thoughts. It is an enormous subject that I try to bring down to reasonable dimensions so that I can include it all. As will be clear, I am interested in painting the big picture on a small canvas.
If we are a bacterium, or an elephant, or a human being, we have our own size worlds, and for each of us there are things smaller and larger than ourselves. But no one can escape the universal rules imposed by size.
In looking at the subject of biological size in its entirety, from large to small, from plant to animal to microbe, it will be evident that everything is interconnected. An examination of the effects of size is a way of bringing all life together.
Just as the content of this book has almost taken a lifetime to mature, the actual writing has been an equally painful and slow process with innumerable adjustments and corrections in my course as I proceeded. These were greatly helped by the kindness and wisdom of numerous individuals to whom I am deeply indebted. Before I even began the book, my colleague Henry Horn was enormously helpful (as he has always been over the years) in purifying my thoughts about size. At a very early stage of writing I had the help of my friend Jonathan Weiner, who urged on me the need for a sense of direction. The first complete draft of this book (still in its underwear!) was prematurely sent to two anonymous readers, and while the comments of one of them were highly critical, they gave me the needed jolt at just the right moment. Later drafts were greatly improved due to the comments of Sam Elworthy, Brian Hall, Slawa Lamont, Mary Jane West-Eberhard, and another anonymous reviewer. Also I want to thank David Kirk for his help with the section on Volvox and its relatives, and my colleague Ted Cox on some matters of physics. I almost feel as though they all ought to be listed as co-authors. My special thanks to Alice Calaprice and Deborah Tegarden for their skill and great help in seeing the book through its final stages of preparation. Finally I would like to thank Hannah Bonner for applying her superb illustrator skills to produce seven of the original drawings.
MARGAREE HARBOUR
Cape Breton, Nova Scotia