Polarized cylindrical body in the epididymis of the flying squirrel

Spermatozoa in the head of the epididymis of the flying squirrel have large cup‐shaped acrosomal heads with two ventral ridges. The cytoplasmic droplet contains an ovoid body and a group of large granules. These structures may be related to the chromatoid body of spermatids. The spermatozoa form polarized cylindrical bodies with centrally placed tails and peripheral heads. The tips of acrosomes protrude into concavities of acrosomal cups of neighboring spermatozoa. Peripheral portions of acrosomes are in contact with microvilli (stereocilia) of epididymal cells. Polarized cylindrical bodies are present in five species of Sciuridae.