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. So deep inside the wall of our seminar phil's tubule are the stem cells of the male gonas known as spermatogonium. Now, spermatogonium are diploid cells and that means in humans the chromosome number of spermatogonium is 46. So when lathic cells produce our testosterone, it stimulates the spermatogonium to differentiate into the primary spermatocyte, also a diploid cell.