If the white cells be required, as in local suppurating abscess, general septicaemia, acute pneumonia, &c., there is an active proliferation of the myelocytes to form the polymorpho-nuclear leucocytes, so that we have in this condition a leucoblastic transformation of the fatty marrow.
The polymorpho-nuclear leucocytes are seen in great numbers in the blood vessels.
To replace this cellular destruction there has been a demand for reinforcements on the home centres of the polymorpho-nuclear leucocytes - the bone marrow.
This call is immediately answered by an active proliferation and steady maturing of the myclocytes in the marrow to form the polymorpho-nuclear leucocytes.
It has been proved that the pyo-genic bacterial toxins, if not too concentrated, will attract the polymorpho-nuclear leucocytes, but if concentrated, may have a repelling influence.