After the skin is pierced and the wound becomes infected, leucocytes from all the body are attracted to this place.
Just what attracts them is not known - the process is called chemotaxis - probably some by-product of bacterial metabolism.
Bacteria trapped in lymph nodes provoke the formation of them.
It is possible to demonstrate the nature of the suspension by centrifuging a sample of whole blood in a test tube for a short time at low speed. 13.1 Separation of blood into cells and plasma by centrifugation.They wage war on the invaders, engulfing the bacteria within their own protoplasm, a process called phagocytosis (literally «cell-eating»). Before the infection is not too overwhelming, the victory usually goes to the leucocytes. Thus in guinea pigs it has been possible to trace the route of tubercle bacilli from the intestines to the lungs, as the route is marked by successively infected lymph nodes.1. About 65 per cent of all white cells are leucocytes. Those leucocytes that stain neutral dyes - as the majority do About 1.5 per cent of the total stain with acid dyes and are called eosinophils.And a still smaller number, 0.5 per cent, have granules that stain with basic dyes; these are called basophils.