So generally, we can divide leukocytes into these three categories. We have granulocytes, agranulocytes and megacaryocytes. And then we can even further subdivide all these categories and we'll discuss that in just a moment. So leukocytes, the white blood cells, are found circulating in the blood plasma in our lymph system and also inside our tissue. And actually, leukocytes are amoebilike cells. And what that means is leukocides can actually move independently of other cells and other structures inside our body.