PA THOLOG Y— HI STOP A THOLOG Y 



1571 



proved that this is the verruga of man, and the ordinary laboratory 

 animals cannot be infected with the disease. According to some 

 observers, the infection in man begins with a general illness, 

 which would appear from the fever, the anaemia, and the pains 

 in different parts of the body, to be of the character of a 

 septicaemia, after which the typical eruption appears on the 

 skin, mucous membranes, and internal organs, when as a rule 

 the general symptoms of fever, etc., abate, from which one 

 would infer that the organism had left the blood stream, and become 

 located in the skin and other organs. It is possible that it leaves the 

 body by way of the skin. If, however, the local lesion develops in 

 such places as the meninges, the choroid plexus, the choroid coat 

 of the eye, the intestines, the oesophagus, or larynx, severe symptoms 

 are apt to appear, and complicate the illness. If at the same time 

 a paratyphoid-like infection takes place during the febrile stage, the 

 true symptoms are masked, and a peculiar and very deadly type 

 of fever, called ' Carrion's disease,' is produced. 



The morbid anatomy is characterized by marked pallor of the 

 body, oedema and dropsy, hypostasis of the lungs, enlargement of 

 the liver and spleen, and hyperaemia of the bone-marrow; but 

 apart from these general signs, the characteristic features are the 

 appearance of the verrugas in the skin and subcutaneous tissues, in 

 the ocular and palpebral conjunctivae, the mucosa of the nose, the 

 lips, gums, palate, tongue, pharynx, larynx, trachea, oesophagus, 

 stomach, small and large intestine, in the substance of the liver, 

 spleen, lungs, thymus, thyroid, testicles, kidneys, and lymphatic 

 glands, and at times in the leptomeninges, the choroid plexuses, the 

 choroid coat of the eye, in the substance of the muscles, on the 

 periosteum of bones, on the peritoneal coverings of organs, and on 

 the pleura and pericardium. 



Histopathology. — ^The histopathology of the disease has been 

 carefully studied by Letulle, Jamayo, Escomel, Jeanselme, Her- 

 cules, Biffi, De Vecchi, and very completely by Strong and 

 his co-workers. The miliary and nodular forms take origin around 

 the capillary bloodvessels in the form of a neoplasm which 

 is the reaction of the areolar tissue to some perivascular 

 irritant. The connective-tissue fibres become swollen, and 

 between them lie embryonic connective-tissue cells, while the 

 interareolar spaces contain polymorphonuclear cells and macro- 

 phages. Microscopically a non-ulcerated skin lesion shows the cells 

 of the surface epithelium swollen and distended with glycogen. The 

 papillary layer of the cutis has disappeared, and the dermis proper 

 is infiltrated with round cells, which are mostly mononuclear or 

 polymorphonuclear leucocytes, separated by a slight amount of 

 fibrillar connective tissue, which may in places be entirely absent. 

 There is some doubt as to whether the connective-tissue corpuscles 

 contribute to the round-celled infiltration, as has been asserted by 

 Izquierdo; in any case, the recognizable connective-tissue cells are 

 always swollen, and their nuclei are altered in various ways. The 

 cellular infiltration is very vascular, and in the case of the older 



