Ever since I was given an old plastic lunchbox containing a sample Physarum culture, I have been fascinated by this biological system. I had been about to teach schoolkids about computing and was hoping to motivate them with patterns found in nature, and was told about this odd slime mold that can solve the minimum spanning tree problem--in the form of a gooey and smelly practical demonstration that could appeal to kids’ sense of fun. The schoolkids seemed to have had a great time in the teaching session while being introduced to the concept of algorithms, and I was hooked too. I have since become aware that there is a vast variety of research ranging from experimental biologists to electronics and theoretical computing that makes use of the very intriguing properties of Physarum.

This very, very extensive volume (of over 800 pages) is an excellent introduction to the area, but it is also particularly useful to those both new to the system as well as experienced researchers who wish to understand practical and low-level details from one integrated source rather than searching through many research articles and technical reports. Each area of interest is covered at a very deep level in various consecutive chapters. While the editor appears as coauthor for many of the chapters, there are many different authors who provide independent views. Of course, having so many authors means that consistency in both quality and style can be varied, and I was concerned when I saw an egregious use of “it’s” slip in as early as page 5; overall, though, the chapters are well written and extensively illustrated with many photos of the experimental setups.

It would have been useful if there were a bit more structuring and cross-referencing between the chapters. In fact, the chapters are not even numbered, so it becomes difficult to annotate the text with references apart from page numbers. While several themes connecting chapters emerge, these have not been made explicit. Apart from a broad division into three parts (“Experimental,” “Theoretical,” and “Music and Arts”), there is no summative preamble or resolution for individual themes, such as the use of Physarum as an electronic component or the use of photochemical attractants, and so on. While the volume brings individual contributions physically together, it doesn’t use the opportunity to make an overall broad remark about the current status and road map for future work. The titles of the first two chapters refer to preliminaries and future directions; a corresponding final chapter, which actually refers back to individual chapters, would have been a great addition.

However, there are probably many pragmatic reasons why such an attempt to cross-link and summarize wasn’t attempted. As it is, putting together this volume must have taken a significant amount of effort, and the editors and authors must be commended for having produced such an interesting and useful volume. I hope it serves to introduce many researchers, in fields as varied as computing, electronics, nanotechnology, and digital art, to this very appealing biological system, and I hope these researchers join me in keeping a nice smelly slime mold culture in their office cupboards to impress colleagues and visitors, both young and old.