LEUKH^EMIA. 217 



in thickness, but have also extended either upwards or down- 

 wards along the vessels to which they are attached (fig. 69). 



The overgrowth of the Malpighian bodies naturally contri- 

 butes a new element to the existing causes of splenic enlarge- 

 ment. The spleen attains the greatest length, breadth, and 

 thickness of which it is susceptible. Inasmuch however as the 

 morbid phenomena must run their course in a space limited by 

 the size of the splenic capsule, it is self-evident that degenerative 

 changes must coincide with the hyperplastic processes in order 

 to make room for the latter. The former chiefly affect the pulp, 

 which, wedged in between the continually growing Malpighian 

 bodies, perishes in large portions at a time. This is always asso- 

 ciated with an abundant production of pigment, which reaches 

 its maximum in the immediate neighbourhood of the glistening 

 Malpighian bodies, giving rise to an exceedingly variegated 

 ^' granitic" marbling of the cut surface. The consistency of the 

 organ conforms to that of its chief constituents, the Malpighian 

 bodies ; it becomes peculiarly tough, more than leathery, almost 

 wooden. In addition to all this, we have chronic inflammatory 

 changes in the peritoneal coat which give rise either to smooth 

 or reticulated thickenings of cartilaginous hardness, or else to 

 highly vascular membranous adhesions connecting the spleen 

 with the nearest abdominal viscera. 



§ 181. With splenic leukhaimia Vircliow contrasts that rarer 

 form to which he gives the name of lymphatic leitkhcemia ; it is 

 characterised from the first by the predominant way in which the 

 lymphatic glands are affected, while the splenic tumour is either 

 secondary or altogether absent. The glands do not all swell at 

 once ; the disease usually begins in an inguinal or axillary gland 

 and spreads first to all the glands in the same region ; it then 

 extends inwards in the direction of the thoracic duct, involving 

 the mediastinal or retroperitoneal groups of glands ; then other 

 peri2:>heral glands take on the morbid action, until every lym- 

 phatic gland in the body is more or less enlarged. The indi- 

 vidual glands often attain from three to five times, occasionally 

 even ten times their natural size. Nevertheless, an anatomical 

 investigation shows nothing beyond a simple overgrowth in 

 every case. This indeed is clear enough from the fact that even 

 in cases of extreme enlargement the lymph-paths remain open, 

 and the lymphatic sinuses of the gland can be injected both 



