BACILLUS MALLEI 227 



in the center, break down, and leave irregular ulcerated cavities. 

 Similar lesions occur in the lungs, in the liver, and in the spleen. 

 In " farcy " the infection usually takes place through an abrasion 

 of the skin; the lymphatics near the wound become thickened 

 and tense and are spoken of as " farcy pipes " or " farcy buds " ; 

 Suppuration usually follows, resulting in deep ulcers with ragged 

 edges and frequently a purulent discharge. 



In man the disease occurs either in an acute or a chronic form. 

 In the acute form an inflammatory swelling appears at the point 

 of infection, which is usually the hand or arm, and a redness 

 spreads along the line of the lymphatics as in a poisoned wound. 

 A pustular eruption soon appears which may be local or cover a 

 large area ; in addition suppurative foci may occur in the lungs 

 and other internal organs. In about 60 per cent of all cases the 

 disease ends fatally in from two to three weeks. 



In the chronic form a local ulcer forms which tends to spread 

 deeply and superficially; the disease may run a chronic course 

 for years and recovery may eventually occur, or, on the other 

 hand, it may at any time change into the acute form and rapidly 

 become fatal. 



The glanders nodule has been considered by some authorities 

 to be structurally similar to that formed by the tubercle bacillus. 

 It is generally agreed, however, that in glanders there is a more 

 marked inflammatory reaction and leukocytic infiltration and 

 that the tissue changes are of a degenerative rather than of a 

 proliferative nature. Caseation, which is so marked in tubercu- 

 losis, does not occur in the same degree in glanders, nor are the 

 typical giant cells formed. 



The mode of infection amongst horses is not definitely known. 

 Recent evidence tends to show that it takes place mainly by the 

 way of the alimentary tract. Since the bacilli are numerous in 

 the nasal discharge, the public drinking trough may in a measure 

 be responsible for the spread of the disease. In man infection 

 probably only occurs through a break in the skin. 



Diagnosis. Several methods have been devised which greatly 

 facilitate the diagnosis of glanders ; of these the mallein reaction, 



