Unfortunately, an earthworm has little internal anatomy (at least that a 16-year-old can find), so we ended up copying what we should have seen from the blackboard. My distaste for the exercise was compounded by the fact that my father had told me never to kill a worm as they were so valuable in the garden. So I abandoned science for the humanities.
Yet the worms eventually brought me back to biology and its history. Many years later, I discovered that Charles Darwin's last book was about earthworms. He spent years discovering how worms create and maintain the topsoil, sustaining agriculture. It is a book about how tiny changes accumulate to shape the world.
Even so, I bored my first classes by presenting the history of biology as a series of great men and their great ideas. But the next year, I re-told the story of evolutionary biology as one about fruit-flies, guinea-pigs, passion-flowers and evening primroses.
Examining the organisms that made modern biology possible has two benefits.
First, they remind us that science is largely about time-consuming hard work, not just inspiration. Talking about the organisms shows that, far from being boring, the hard work is what makes the ideas possible. Even Darwin could not have come up with his theories without many hours of watching worms. The worms also remind us how many people Darwin depended on. Throughout the worm book are acknowledgements of help from "a lady, on whose accuracy I can implicitly rely", a French geologist, the keeper of an Indian botanic garden, and many others. Far from being a "lone genius", he was at the hub of a global network of correspondents.
Biology has continued to work like this since, and I wish someone had told me that at school. The sense that science was something everyone could contribute to might have kept me in the lab. Even if it hadn't, knowing something of how science works might have helped me understand the ways in which it would affect my life.
With the Earth potentially facing the greatest mass extinction in its history, we need biologists more than ever, and an understanding of what biology is and why it matters - because we are all earthworms: the cumulative effect of all our individual acts of consumption is changing the planet and we need to understand how.
The author's first book, A Guinea Pig's History of Biology, is published on May 23 by William Heinemann
Jim Endersby is a lecturer in the history department at the University of Sussex