Light micrograph of a seminiferous tubule in cross-section containing the seminiferous epithelium showing the process of spermatogenesis. Elongating spermatids form radially arranged columns between which are the earlier generations of maturing and proliferating germ cells. The tubule is supported by the surrounding intertubular tissue. Epoxy resin section, toluidine blue stain. Magnification: x40 when width printed at 10cm.