Kutrib introduces a new computing model called pushdown cellularautomata, which is obtained by replacing finite automata in traditionalcellular automata with pushdown automata. Natural restrictions of thismodel, called real-time and linear-time pushdown cellular automata,respectively, are also introduced. The main results contained in thepaper are two fundamental language-theoretic properties of theseautomata, namely, computational power and closure properties. The formerproperty is shown by proving inclusion and incomparability relationsamong the classes of languages for the automata defined in this paperand other known classes of languages defined by traditional cellularautomata and sequential automata. The operations considered for thelatter property include union, intersection, complementation,(erasing-free) morphisms, inverse morphisms, substitutions, andreversals; these are some of the most fundamental language-theoreticoperations. The paper is well written and should interest theoreticiansof formal languages and automata.