INFECTIVE GRANULOMATA. 363 



sistance to light, dessication and other external influ- 

 ences and consequently the infection in discharges is as a rule, 

 promptly destroyed. The lenqth of time that the l]acterium 

 mallei may exist outside of the animal body and retain its viru- 

 lencv has never been absoluteU' determined. Authentic cases 

 of glanders have appeared in liorses that had l)een placed in 

 stalls that had been vacant for one year, but prior to that time 

 occupied bv glanderous horses. A few reports are indicative of 

 the fact tiiat the Bacterium mallei may retain its virulence in 

 infected buildings for two (3r even three )-ears, but these re- 

 ports need further sul)stantiation. It seems probable from clin- 

 ical and experimental evidence that, except in the animal body, 

 the virulence of Bacterium mallei is rarely retained longer than 

 one year. 



In cities, public drinking fountains, hitching posts and feeding 

 troughs are probably the greatest sources of infection. The 

 purchase of second hand harness, wagons, and other e(|uipmcnt 

 should be regulated by ordinances or laws to pre\ent the 

 spread of such infections as glanders. 



The Channels of Entrance of the Infection. — All exposed 

 surfaces and natural ojjenings of the bod}' ma-\' permit the Bac- 

 terium mallei to gain entrance to the tissues. In glanders, as 

 in tuberculosis it has been quite conclusivelv demonstrated 

 experimentallv that the majority of the cases of glanders results 

 from the ingestion of the Bacterium mallei. No doubt infection 

 may occur by inhalation of the infectious agent and an occa- 

 sional case mav be the result of cutaneous inoculation. It is 

 possible for the discharges containing the Bacterium mallei to 

 become pulverized and carried by air currents and in- 

 haled. Farcy may or may not result from cutaneous infec- 

 tion. Such inoculations are easily accomplished by bridles, 

 harness, saddles, curry combs, etc. More rarely the conjunc- 

 tival membrane may be the channel of entrance. For example 

 a horse, affected with nasal glanders may sneeze or cough and 

 thus infection be forcibly introduced onto the mucous mem- 

 brane of the eye of another horse. 



■Lesions.— macroscopic— The lesions of glanders are fou.nd 

 especially in the mucous membrane of the anteri.ir respiratory 

 passages, Ivmph nodes, lung and skin, the frequency being m 

 the order mentioned. It is probable that the Bacterium mallei 

 primarily affects lymphoid tissue. The gross lesions may be 

 diffuse or circumscribed, depending upon the virulency of the 

 infecting organisms and the resistance of the affected animal.. 



Dififuse glander lesions are usually found in annuals having- 



