Annu. Rev. Astron. Astrophys. 1982. 20: 517-45 Copyright © 1982 by Annual Reviews. All rights reserved

Reprinted with kind permission from Annual Reviews, 4139 El Camino Way, Palo Alto, California, USA

Table of Contents

• INTRODUCTION
• GALAXIES WITH ABUNDANT MOLECULAR GAS
• OH Absorption Surveys
• CO Emission Surveys
• THE DISTRIBUTION OF MOLECULAR MATERIAL WITHIN GALAXIES
• Maps of Carbon Monoxide Emission
• A Classification Scheme
• MOLECULAR CLOUDS IN THE CENTRAL REGIONS OF GALAXIES
• Is There a Distinct Central Concentration of Molecular Clouds?
• Optically Thin CO
• OH Absorption-Line Anomalies
• Correlations of Molecular Sources with Nuclear Activity
• Seyfert Galaxies
• MOLECULAR CLOUDS IN GALACTIC DISKS
• Spiral Arms, Bars, and Giant Complexes
• Interrelations of Far-Infrared, Nonthermal Continuum, and CO Emission
• Implications for Star Formation
• NGC 5128 - A Special Case
• EXTRAGALACTIC CHEMISTRY
• EXTRAGALACTIC MASERS
• PERSPECTIVES
• REFERENCES