HISTOLOGY. 55 



These multiply and lose their nuclei and acquire hemo- 

 globin. Later in life the spleen and red marrow of the 

 bone contribute to the supply of red cells. The white 

 blood cells are derived mostly from the lymphoid tis- 

 sue and spleen. The lymphoid corpuscles become dis- 

 lodged and carried along the blood current or lymph 

 current, as the case may be. "In these places they un- 

 dergo a mature change." Lcroy. 



Exercise No. 36. Make a stained preparation of 

 blood. 



1. Make a spread in the usual way. 



2. Fix high over the flame. 



3. Apply eosin 30 minutes. 



4. Haematoxylin 3 minutes. 



5. Dry, mount and label. 



6. Study and preserve, 



Search for the four varieties of lymphocytes and 

 observe the formation of rouleaux in the red cells. 



