This is a collection of short stories all set on the world Mirabile, and all centering around Mama Jason and the unpredictable wildlife of the planet Mirabile. Settled by humans at some unspecified time in the future, it is now the site of a struggling human colony that arrived in damaged colony ships with genetically engineered embryos of earth wildlife, but incomplete instructions about both what they have, and how they have been altered. For reasons of efficiency that are a bit glossed over, it appears that when the embryos for the colony ship were created, DNA from multiple species were combined into each embryo, with instructions on how to activate one or the other genome depending on what the colonists wanted. Those instructions, however, were part of the data loss, with the result that the new colonists are stuck with a bunch of embryos that may not necessarily breed true. So flowers may, under the right environmental conditions, give rise to insects; deer may give birth to wild hogs; and stranger and more dangerous hybrids (locally called "dragon's teeth") can appear which Mama Jason and her team need to identify and take care of. Genetic analysis becomes a matter of fundamental importance and in these short stories Mama Jason and her team deal with a series of puzzles and crises relating to the strange local ecology and the place that earth wildlife is creating within Mirabile's ecosystem. Considering the age of the book it's got an impressively decent grasp of ecological and genetic issues, and in particular the way an ecosystem can be delicately balanced in ways that may not necessarily be immediately obvious to humans. It's very sad Kagan died so young and before writing more than she did, as her early stories were all very well thought out and interesting, and I'd have loved to read more of them.