QUARANTINE REGULATIONS.
The sanitary regulations issued by the Department of Agriculture for the control of cattle shipments from the infected districts have for their initial purpose the prevention of the transportation of ticks from infected regions to those that are not infected, either upon cattle or in stock cars or other conveyer. They are based upon the fact that Texas fever is carried north only by the cattle tick, and the exclusion of this parasite from the noninfected territory has in every instance been found a certain method of excluding Texas fever. The regulations governing the movement of cattle from below the quarantine line are made yearly by the Secretary of Agriculture, and they define the boundary of infected districts. The infected area as now determined is shown in maps issued periodically.
SOUTHERN CATTLE FEVER (TEXAS FEVER, TICK FEVER).
DESCRIPTION OF PLATES.
Plate XLIV. Normal spleen and spleen affected by Texas fever.
Fig. 1. Spleen of an acute, fatal case of Texas fever. The narrow end of the spleen is here represented.
Fig. 2. Spleen of healthy steer. Though the latter animal weighed one-half more than the former, the weight of the diseased spleen (6-7/8 pounds) was nearly three times that of the healthy spleen (2-3/8 pounds).
Plate XLV. Texas fever.