The manchette is a transient microtubular organelle previously considered to "disappear" prior to formation of the definitive midpiece of the spermatozoon. Goodrowe and Heath (1984) have suggested, however, that in stallions the final disposition of the microtubules of the manchette is into the residual cytoplasm. In the present study, spermiogenesis was examined by transmission electron microscopy of testicular samples from eight cats. Feline spermatids also had a manchette of cylindrical shape, largely located in a cytoplasmic collar peripheral to the presumptive midpiece. The parallel microtubules of the manchette were interconnected by arms. Some of these arms were still present after rupture of the manchette cylinder and movement of the microtubules into the residual cytoplasm. On displacement of the manchette microtubules, mitochondria, spherical in shape and peripherally located, moved centrally to elongate and encircle the flagellum to form the definitive midpiece.