Biometry of human spermatozoa.

Abstract

SYNOPSISA description is given of investigations on size distribution of normal human spermatozoa. The size distribution curves found are not Gaussian but logarithmic, and can accurately be described by the equation:where N = number of sperm heads with length L, Nmax = number of sperm heads having the most frequently occurring length Lme = base of Napierian logarithmsk = a constant.A similar distribution was found for the length and the breadth of the nucleus.In addition, empirical formulae for calculating the area of the optical longitudinal section of the sperm head and its volume were derived from model experiments. The area of the section can be calculated with fair accuracy for practical purposes from the equation:where L = length and Bmax is the breadth at the broadest part. The empirical equation for the volume V is:where d = thickness. Using this equation, the volume of a sperm head of the most probable dimensions L = 4.4 μ, Bmax = 3.2 μ and d = 2.0 μ is found to be 6.4 μ3 ± 0.4.Methods for calculating the volume of the middle‐piece, the tail, and the tail‐end are also discussed.Some estimates of weight, based on measurements with the Baker interference microscope, are given.