[Comparative morphological and functional studies on infertility of males (author's transl)]

Male infertility is common. It usually is attributable to impaired maturation of germinal cells. The causes are related to the following factors: 1. Defective development of the gonadal ridge; 2. Abnormality of chromosomes; 3. Disorders in pituitary function; 4. Exogenous effects; 5. Unknown aetiology. -- Differentiation is difficult between those causes which often cannot be discovered at all. Therefore, assessment of male infertility is undertaken with reference to findings obtained from seminal, histological, immunological, cytogenetic, and hormonal tests as well as from electron microscopy.