The publication in English of this monograph seems to me to indicate the ever- increasing interest of astrophysicists in the physical and dynamical problems of planetary nebulae-one of the most interesting and fruitful branches of theoretical astrophysics. Their interest in part arises from the fact that the methods of identify- ing the physical processes occurring in planetary nebulae, as well as the many theo- retical results, are now acquiring a degree of uni versality as their sphere of application increases. Finally, the special cosmic significance of planetary nebulae is becoming...