Selective degradation and fractionation techniques developed for bovine sperm enabled examination of the structure and chemical properties of components within the tail and neck regions. The degradation methods used caused specific detachment of the capitulum from the implantation fossa of the nucleus. After fractionation and negative staining, the connecting piece was flattened and asymmetrical in shape and had a protuberance located on one side. As a result of chemical digestion, the anterior portions of the cross-striated longitudinal columns remained attached to the capitulum while the posterior portions were connected to individual, pairs, or trios of outer dense fibers (ODF). The major longitudinal columns had greater resistance to breakage than the minor columns. The ODF had regular oblique striations and exhibited strong bonding with the mitochondrial sheath and the cross-striated longitudinal columns. Adenosine triphosphatase (ATPase) activity and carbohydrates were shown to be associated with the mitochondria-outer dense fiber (M-ODF) fraction.