The length each stage of the cycle of semi-niferous epithelium occupies on the seminiferous tubule, was determined by continual paraffin sections of the seminiferous tubules.

• 3．应用精细管的连续石蜡切片测定了小白鼠生精上皮周期各期在精细管上所占的长度，并观察了它们在精细管上的排列顺序。