Detail of the wall of two contiguous seminiferous tubules observed with the objective of 100x. We can perceive the wall structure, constituted by germinal cells at different development stages and by Sertoli cells. Going from outside inwards we can distinguish different types of germinal cells: spermatogonias, primary and secondary spermatocytes and spermatids (they are more developed [yellow] when nearest to the tubule lumen) . Each tubule is surrounded by a thin lamina propria and between the tubules there is connective tissue.