We show that contrary to recent claims, the Lagrange and Heisenberg equations of motion are the same for the quantized charged spin-$\frac{3}{2}$ field in the presence of a minimal external electromagnetic interaction. For dynamical systems with constraints depending upon external fields, the explicit dependence of the dynamical variables upon these external fields must be taken into account.

• Received 17 July 1972

DOI:https://doi.org/10.1103/PhysRevD.8.1088