Typhus Fever and Pediculida 237 



disassociation of the spirochaete into granules as simply the first 

 phase, not of a process of multiplication, but of a degeneration 

 ending in the death of the parasite. The fragmented chromatin 

 has lost its affinity for stains, remaining always paler than that of 

 the normal spirochaetes. On the other hand, the granules of Leish- 

 man stain energetically with all the basic stains. 



Further, according to Marchoux and Couvy, infection takes 

 place without the emission of the coxal fluid and indeed, soiling of the 

 host by the coxal fluid diluting the excrement is exceptional. All 

 of the organs of the Argasid are invaded by the parasites, but they 

 pass from the ccelom into the acini of the salivary glands and collect 

 in its efferent canal. The saliva serves as the vehicle of infection. 



Thus, the question of the life cycle of Spirochceta gallinarum, and 

 of spirochsetes in general, is an open one. 



It should be noted that Argas persicus, the carrier of Spiroch&ta 

 gallinarum, is a common pest of poultry in the southwestern United 

 States. Though the disease has not been reported from this country, 

 conditions are such that if accidentally introduced, it might do great 

 damage. 



Other Spirochaete Diseases of Animals About a score of other 

 blood inhabiting spirochaetes have been reported as occurring in 

 mammals, but little "is known concerning their life-histories. One 

 of the most important is Spirochczta theileri which produces a spiro- 

 chaetosis of cattle in the Transvaal. Theiler has determined that it 

 is transmitted by an Ixodid tick, Mar gar opus decolor atus. 



TYPHUS FEVER AND PEDICULID^E 



Typhus is an acute, and continued fever, formerly epidemically 

 prevalent in camps, hospitals, jails, and similar places where persons 

 were crowded together under insanitary conditions. It is accom- 

 panied by a characteristic rash, which gives the disease the common 

 name of "spotted" or "lenticular" fever. The causative organism 

 is unknown. 



Typhus fever has not generally been supposed to occur in the 

 United States, but there have been a few outbreaks and sporadic 

 cases recognized. According to Anderson and Goldberger (19120), 

 it has been a subject of speculation among health authorities why, 

 in spite of the arrival of occasional cases in this country and of many 

 persons from endemic foci of the disease, typhus fever apparently 

 does not gain a foothold in the United States. These same workers 



