So the red portion is the wall of the seminefriendly stewart. This is the basement membrane and this is the interstitulum. It's the interstitial space. Now, inside the interstitial space we have blood capillaries and we also have these cells known as Ladic cells. Now, what Ladic cells do is they produce and release a special type of hormone known as testosterone. And what testosterone does is it stimulates the stem cell, the precursor stem cell known as spermatogonium, to differentiate into a diploid cell known as the primary spermatocide.