216 MORBID STATES OF THE BLOOD, ETC. 



with the insertion of the larf^er trabecula?, these takinor a lon'^'er 

 time to accommodate themselves to the enlar^rement of the oro^an 

 as a whole. The capsule too does not admit of any very sudden 

 distension. In my notes of Virchoiv^s practical course (Berlin, 

 1857-58) I find a case of splenic leukhsemia in which the spleen 

 (in the stage of parenchymatous congestion) was swollen till it 

 measured one foot in length, two inches in thickness, and five 

 inches in width ; and in consequence of this, a rupture of the 

 capsule had occurred. The fissure, masked by clotted blood, 

 was three lines in length, and passed at each end into a com- 

 mencing dissociation of the capsular fibres, preliminary to an 

 extension of the tear. 



§ 180. As the disease advances, an overgrowth (hyperplasia) 

 of the Malpighian bodies — or as we must call them nowadays, 

 the lymphoid sheaths of the arteries — developes itself more 

 and more. The first step in the process is an accumulation 

 of leucocytes in their interior, produced by fission of those 



Fig. 69. 



Cut surface of spleen in the second stage of leukliajmic swell- 

 ing. Enlargement of Malpighian bodies. Atrophy with 

 pigmentation of the pulp. 



already present. This proliferation is followed by a dilatation of 

 the delicate fibrous reticulum between the cells, and subsequently 

 by a proportionate formation of new capillaries, so that the 

 enlargement of the Malpighian bodies really implicates every 

 one of their three constituents, and must therefore be regarded 

 as a true overgrowth. The Malpighian bodies are now very 

 distinct on the cut surface of the spleen as white, tough, resist- 

 ant nodules ; they exhibit, more often than under normal con- 

 ditions, a tendency to bifurcate, nay even to brenk up into a 

 number of branches, a proof that they have not only increased 



