The Asexual Cycle in Leucocytozoon anatis

Young ducks were brought to the University of Michigan Biological Station in the summer of 1927. These were not infected upon arrival but plainly showed Leucocytozoon anatis after being kept ten days near other ducks infected with this parasite. During this time blood samples were taken daily. Since the manner and time of infection were not determined, it was not possible to be accurate in giving the age of any parasite subsequently found. However, from the daily samples it was found possible to work out the various developmental stages and to assign ages which appear correct to within not more than three days. The earliest parasites found were in young red blood cells (Figs. 3-5), and appeared similar to young stages of bird malaria. The parasite possesses a cytoplasm which with tetrachrome stain distinctly stains blue, and a nucleus which stains red. The normal young red blood corpuscle has a larger and less compact nucleus than the older cell; the cytoplasm takes more azur stain and less eosin than do the mature red cells.