THE LEUCOCYTOZOA 



253 



contents such as the nucleus. Consequently the movement 

 of the invader is greatly altered. 



When a young L. musculi has penetrated a leucocyte, it 

 remains at first near the periphery (fig. 2, a), and so directs its 



Fig. 2. — Varying forms of a single living Leucocytozoon musculi. 



Diagrams of a young intra-corpuscular parasite observed in the living condition for seven hours. In these 

 diagrams the cytoplasm of the parasite is represented by small dots, more closely aggregated where the 

 protoplasm stained more deeply (intra-vitam). Vacuoles are left clear. The chromatin of the parasite 

 is represented black in g-k, and the nucleus of the leucocyte is shown by shaded lines. The outline 

 of the leucocyte is indicated by a circular area. (After Porter.) 



movements that it partly surrounds the nucleus (fig. 2, b, c). 

 Osmotic diffusion from the cytoplasm of the host to the parasite 

 occurs, producing vigorous movements within the leucocyte, 

 accompanied by fairly rapid growth of the parasite. The move- 

 ment of the latter is more noticeable at one end. This appears 



