32 Pathologic Anatomy and Histology. 



with blood. Occasionally gelatinous infilration is seen in 

 the valves, but this change is not pronounced in the 

 chronic cases. 



The most prominent change of the disease is notice- 

 ably in the blood. It decreases immensely and in the 

 extreme cases the lethal quantity of the blood drawn 

 does not reach 10 litres. As to the detailed descrip- 

 tion of the changes in blood, the reader will find it 

 in the next section. 



The lymph-glands both superficial and visceral are 

 more or less swollen, the largest reaching the size of a 

 walnut or a hen's egg. This is especially the case with 

 those of the mesentery and of the spleen. The glands 

 are soft, juicy and pulpy in section surface. They are 

 usually light reddish brown with yellow markings or 

 grayish black fiecks. 



Changes of the bone-marrow is very marked next 

 to those of blood. In the acute cases, the cross section 

 of long bones, such as the femur, or humerus, shows that 

 the bone-marrow changes wholly or in part into dark 

 red with petechiae. In the chronic cases the change is 

 not so extensive as in the acute form, but it develops 

 as the foci. In the protracted cases a small number of 

 foci are invariably present. 



The central nervous system shows scarcely any change 

 at all, excepting the increase of the fluid in the cavity 

 of the arachnoid membrane and the lateral ventricles. 

 Very rarely ecchymoses in the pia mater and small 

 haemorrhagic foci in the gray matter of the spinal cord 

 are found. 



No macroscopic changes are met with in other 

 organs, such as the pancreas, salivary glands, suprarenal 

 body, thyroid gland, or walls of blood vessels. 



