MELAN^MIA. 219 



tides are found among the usual floating constituents of the 

 blood ; in well-marked cases, they occur in every specimen of 

 blood taken from the heart's cavities. Their shape is very irre- 

 gular ; they are made up of yellow, brown, but most commonly 

 of black granules ; most of them are small, smaller at least than 

 red blood-corpuscles ; others are larger, and a few even exceed 

 the red corpuscles considerably in size. 



Here and there we may succeed in demonstrating a trans- 

 parent, colourless membrane investing the pigmentary aggregates 

 and filling up the irregularities of their surface. In rare instances, 

 this membrane is of considerable thickness, and then exhibits a 

 concentric lamination. 



§ 184. In the General Part of this w^ork I spoke at length 

 about the mode in which pathological pigments originate. The 

 remarks I then made are perfectly applicable to the pigmentary 

 particles of melansemla. They are derived from the colouring- 

 matter of the blood, and consist of condensed and altered liaBmatin 

 ])reclpitated in a granular form. Both the circumstances and the 

 locality of their production may be determined with some approach 

 to certainty. Melanj^mlc pigment originates chiefly in the 

 spleen, under the influence of the malarial cachexia (cachexia 

 of intermittent fever). 



The morbid anatomy of intermittent fever starts from an 

 active congestion of the liver and spleen. Both of these organs 

 may attain a very considerable size in consequence. Neverthe- 

 less, it is only after the hypersemla has lasted some time that signs 

 of permanent disorganisation occur. One of these, a diffuse 

 interstitial overgrowth of connective tissue, we shall become 

 acquainted with among the diseases of the liver as an Induration 

 of that organ. The spleen may either exhibit a kind of softening 

 of its entire parenchyma, or an indurative condition which starts 

 from a thickening of its capsule and trabecular network. In 

 very severe cases, such as (thanks to the general use of Peruvian 

 bark) only occur sporadically in Germany, this Is associated with 

 a deposit of pigment both In the liver and in the spleen. 



This is directly traceable to the above-mentioned excessive 

 and prolonged congestion of both organs. In the liver, the 

 pigment makes its appearance just outside the vessels ; number- 

 less minute extravasations into the capsule of Glisson and the 

 hepatic parenchyma form the starting-point of the process. In 



