The lower invertebrates - from sponges to annelids - have been investigated for over a century, but there are fundamental problems that are only now coming under scrutiny. This book gives fresh impetus to the subject area, presenting a broad synthesis of current trends and pointing out areas likely to develop rapidly over the next few years. It emphasizes particularly active research areas, such as ultrastructural (TEM, SEM) work and phylogenetic methods - especially cladistics.
