Observations on Bull Sperm Rotation

Three sets of cinematographic observations are described which attempt to ascertain both whether bull sperm roll, as opposed to rock, and in what direction such rocking or rolling occurs. The first set utilizes the flash shape sequence of the spermatozoan head, the second involves sequential views of asymmetric heads, and the third has to do with the flash color sequence of the head. It is concluded that bull sperm roll and that they roll both left- and right-handedly.