3 Review(s)

The symposium on "Neutral Clouds near HII Regions" was prompted by an obvious need to bring together workers specifically interested in the dynamical and photochemical effects in regions showing clear evidence of on-going star formation. This is currently an are a of considerable research activity with much new observational material over the wavelength range from X-ray to radio. Furthermore, the field isbeginning to mature. No longer is molecular spectroscopy concerned only with the search for new lines and with preliminary surveys. No longer are evolving HII regions modelled with the naive assumption of constant density. Similarly, ideas of successive star formation, "champagne" and "blister" models of HII regions, and refinements to abundance calculations are examples which show that theoretical initiative is keeping pace. We were both surprised and gratified by the number of contributed papers and the extent to which they addressed the subject matter. In the proceedings we have grouped these papers near the most appropriate of the four invited review papers. The subjects of these reviews are in the general areas of "Evolution of HII Regions", "Dynamical Interactions", "Chemistry in Active Regions" and "Infrared and Maser Sources". The symposium comprised 42 orally presented papers and 23 poster papers. AII but two are reproduced in this volume.