This is a fascinating book containing delightful descriptions of the microbial world. It would be hard to find a better introduction to the numerous, yet poorly known, organisms found in every conceivable part of the earth's surface and deep within its oceans and soils. Sagan and Margulis cover everything from viruses to lichens, including such weird life forms as mycoplasmas, methanogens, slime bacteria, crypters, ray beings, slime nets, cellular slime molds, sea whirlers and chytrids.
Sagan and Margulis provide a somewhat dated, but useful, annotated list of references and enough detail about the biology and observation of these organisms to whet the appetite for more. A short chapter on collecting and culturing the microbes is augmented by comments on collection and culture within the discussions of each taxon.
If I have a criticism (other than the fact that the taxonomy is somewhat dated) it would be that the authors should have included a note on safety, as some of the cultures can produce pathogenic organisms. Given these occasional "nasties" it would be worthwhile to emphasize some sanitary precautions. That said, the study of microscopic life is much under rated in the United States (much more popular in Britain!) and perhaps books like "Garden of Microbial Delights," along with a recently published guide to bacteria, may correct that imbalance. It certainly would not hurt if more people became more aware of the teaming billions of organisms in their world, including a host that we depend on for our very existence. If you are at all interested in the microscopic inhabitants of the real world, even if you are not interested in observing them, you should read this book.