Testicular Tangrams

During the past two decades research on the testis has created a vast number of publications. New techniques, such as cell and gene clon­ ing, germ cell manipulation and transplantation, as well as gene ex­ pression, have surpassed the classical approaches that involved studies on receptor activation and endocrine, paracrine and autocrine regula­ tory mechanisms. Due to the expansion of this field of research it has become increasingly difficult to integrate the large number of observa­ tions an