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The UNITED STATES GOVERNMENT l.as ESTABLISHED 

 :a QUARANTINE LINE which is fixed for the regulation 

 •of inter-state trade in cattle, so thatSouthern tick-infested 

 cattle cannot be taken into non-tick-infested States (ex- 

 cep for immediate slau<;liter) dnrinjj: the warm seasons 

 when pastures and susceptible cattle may become in- 

 fected with ticks, and the latter inoculated with the 

 micro-parasite of Texas fever. All tlie States, or parts 

 of States, south of this line are in the tick-infested re- 

 gion, and all north of it are in the tick-free region. This 

 line starts at the Atlantic Ocean, near the southern boun- 

 <iary of Virginia, runs westward, leaving nearly all of 

 North Carolina, all of Georgia, Alabama, Mississippi, 

 Louisiana, and Texas, part of Tennessee, Arkansas, In- 

 dian Territory, New Mexico, Arizona, and the southern 

 part of California south of the Governmental quarantine 

 line, in the tick-infested part of the United States. 



This quarantine line and the fact that all Northern- 

 bred cattle shipped into the South have Texas fever, 

 have led many people to believe that Texas fever occurs 

 only in Northern-bred cattle, and never in the native 

 cattle of the South. But it has been proven in some 

 cases, beyond doubt, that calves are not born immune 

 to Texas fever even though their dams are immune. In 

 truth, it is very probable that all cattle are born sus- 

 ceptible to Texas fever, and only acquire immunity after 

 birth, by having one or more attacks of the fever. The 

 micro-parasite in the blood of the dam can not pass into 

 the foetus in the uterus because the blood in the circula- 

 tion of the mother does not pass directly into the circu- 

 lation of the foetus. The serum of the blood of the 

 mother passes through membranes into the circulation 

 of the foetus and it is very probable that the micro-para- 

 site does not pass through these membranes. Moreover, 

 blood serum contains very few of the micro-parasites. 



