  We introduce a simple branching model for the development of hadronic showers
in the Earth's atmosphere. Based on this model, we show how the size of the
pionic component followed by muons can be estimated. Several aspects of the
subsequent muonic component are also discussed. We focus on the energy
evolution of the muon production depth. We also estimate the impact of the
primary particle mass on the size of the hadronic component. Even though a
precise calculation of the development of air showers must be left to complex
Monte Carlo simulations, the proposed model can reveal qualitative insight into
the air shower physics.
