Asymmetry and sexual dimorphism of lungs weight in fetal ontogeny

1079 male fetuses and 727 female fetuses at the age of 20 to 41 weeks were investigated for the process of asymmetry and sexual dimorphism of lungs weight formation as well as developmental correlation between the weight of the lungs and the size of the heart. Statistical analysis of the results was applied. It was ascertained, among others, that asymmetry of lungs weight occurs in the investigated developmental period--the right lung is heavier than the left one about 20 to 30%. Between the increase in the weight of the lungs and the size of the heart positive correlation occurs, but it is not of directed character. A substantial, intersexual differentiation of lungs weight was not ascertained.