23 



THE MORBID ANATOMY AND HISTOPATHOLOGY OF PLAGUE 

 AS DESCRIBED IN LITERATURE. 



The number of articles on plague which have appeared since 

 the discovery of the specific micro-organism is very considerable. 

 Most of the literature deals largely or exclusively with the clinical 

 aspect, the bacteriology, the prophylaxis, or the serumtherapy of 

 the infection, so that the number of contributions to its morbid 

 anatomy and histopathology is comparatively limited. It is surpris- 

 ing to find, from a lecture delivered by Virchow in 1879, how little 

 was then known of the pathology of the greatest scourge of the 

 Middle Ages. 



Virchow had no opportunity personally to study cases of the disease, 

 and he therefore simply gives a review of the writings of the eighteenth 

 and nineteenth centuries, up to 1879, drawing attention to the then prev- 

 alent contradictory views on the pathology of plague. From these he 

 selected, in an admirably critical manner, those which indeed come nearest 

 to the correct pathology as it is now kno^vn. Virchow's plague lecture 

 in 1879 also contains this remarkable prophetic declaration: "To me the 

 similarity of anthrax and plague is so great that I consider it very possible 

 that we shall find an organism as the carrier of plague infection. However, 

 an attempt to find it has heretofore hardly been made." 



Aoyama, simultaneously with the bacteriologic work which led to the 

 discovery of the plague bacillus, investigated the gross and microscopic 

 pathology of the disease. He described the swelling of the infected lymph 

 glands as brought about by a proliferation of their cells and he noticed the 

 changes found in plague in the periglandular tissue. He stated that the 

 spleen was always considerably enlarged, hyperemic, and soft, the kidneys 

 and the liver somewhat increased in size and much congested, while the 

 cells of these organs showed parenchymatous degeneration. The lungs are 

 described as unchanged. The plague bacilli were found to be present in 

 large numbers in the affected glands but rare or absent in the blood. 



Yamagiwa's observations were made during the latter part of the plague 

 epidemic in Formosa in 1896. While he had access to a considerable 

 number of cases which he could study clinically, his pathologic material, 

 owing to political reasons, was limited to three post-mortem examinations. 

 Besides these he was able to obtain several glands extirpated inter vitam 

 which he included in his microscopic studies. All three of Yamagiwa's 

 cases were bubonic plague, one complicated by a metastatic dissemination of 

 the bacilli in the lungs, spleen, and liver, or, as we would now classify it, a 

 primary bubonic case with secondary plague septicopyemia. However, the 

 summary of the morbid anatomy and histopathology, as given by Yaraagiwa, 

 while quite correct on the whole, does not apply to all cases of plague, as 

 the investigation of a larger amount of material very clearly shows. 



At the time of Yamagiwa's writings plague pneumonia had not 

 yet been described by modern writers, nor was plague septicaemia 



