340 



MICRO-ORGANISMS AND DISEASE [chap. 



not larger than a split pea, others as big as a filbert or 

 walnut, or larger. Some of these nodules are filled with 

 thick, creamy pus, others are yellow and caseous but firm, 

 still others contain calcareous matter. Under the micro- 

 scope the nodules contain in the periphery round cells in a 

 fibrous matrix, amongst them very numerous giant cells of 

 all different sizes, from one only twice or thrice the size of 

 an ordinary leucocyte to that of a real giant, with twenty to 



Fig, 132. — From a Section through Tuberculous Deposits in the Lung or" 



A Cow. 



Two giant-cells and two small cells containing tubercle-bacilli. 



Magnifying power 700. 



thirty and more nuclei all regularly disposed near a peri- 

 pheral zone of the cell. Near the caseous portion these 

 huge giant cells are very conspicuous ; the caseous part may 

 still show the outline of the giant cells, but their nuclei do 

 not take the stain, and the whole tissue of the caseous por- 

 tion is a granular debris. In pronounced and advanced 

 cases, freely projecting nodules, as also nodules within the 

 substance, having a great tendency to suppurate, are met 

 with in the lymphatic glands, in the spleen, liver, and even 



