A single intra-muscular dose of cadmium chloride (0·2 ml of a 0·04 m solution) caused a retardation of the photoperiodic response in the testes of wood-pigeons (C. palumbus) given a 16-hr photoperiod in late February to March. A similar injection administered in August did not affect the normal seasonal post-nuptial regression. Necrosis of the seminiferous tubules was not evident.
An intra-muscular injection given to feral pigeons (C. livia) with testes in full breeding condition, again produced no necrosis of the seminiferous tubules, but interfered with the radial co-ordination of cells in the germinal epithelium.
An intra-testicular injection (0·1 ml of 0·04 m solution) of cadmium chloride into specimens of both species, caused localized necrotic damage as well as a more general disruption of germ-cell co-ordination in the seminiferous epithelium.