When microscope slides are stained to show blood cells, the small red blood cells that appear on the slides are much more numerous than the large white blood cells. I believe this supports the fact that each kind of cell is present in the numbers best suited to meet the needs of the body. In other words it supports the concept of having normal blood. Red blood cells as compared to the white blood cells are really more numerous. In normal cases, human blood contains about 3.6 to 6.2 trillion/ L red blood cells while white blood cells only reaches 5 to 10 billion per Liter.