SOUTHERN CATTLE FEVER (TEXAS FEVER, TICK FEVER). 



DESCEIPTION or PLATES. 



Plate XI^IV. Normal spleen nnd spleen affected by Texas fever. 



Fi.i:. 1. Spleen of an acute, fatal case of Texas fever. The nai'row end of 

 the spleen is here rci)rcseiited. 



Fig. 2. Spleen of healthy steer. Though the latter animal weighed one-half 

 jnore than the former, tlie weight of the diseased spleen (6J i^ounds) 

 was neai'ly three times that of the healthy spleen (2i} pounds). 

 Plate XLV. Texas fever. 



Fig. 1. The cut surface of a healtliy liver taken from a steer slaughtered 

 for beef. 



Fig. 2. The cut surface of the liver in Texas fever. 



Fig. 3. Appearance of the urine in an acute, fatal case of Texas fever. 



Fig. 4. Red corpuscles, magnified 1,000 diameters, conlaining the parasite of 

 Texas fever. This ajipears as a blue point a near the edge of the 

 corpuscle. The blood was taken from a skin incision. The case was 

 nonfatal and occurred late in the fall. 



Fig. 5. Red corpuscles from the blood of an acute, fatal case, 20 hours be- 

 fore death. The Texas fever microbes a are shown as pear-shaped 

 bodies, stained with methylene blue, within the red corpuscles. The 

 larger body on the right & is a white blood corpuscle, also stained with, 

 methylene blue. (JIagnified 1,000 diameters.) 

 Plate XLYI. The cattle tick (itaryaropiis muiiilatus) . the carrier of Texas 

 fever. 



Fig. 1. A series of ticks, natural size, from the smallest, just hatched from 

 the egg, to the mature female, ready to drop off and lay eggs. 



Fig. 2. Eggs, magnified 5 times. 



Fig. 3. The young tick just hatched (magnified 40 times). 



Fig. 4. The male after the last molt (magnilied 10 times). 



Fig. 5. The female after the last molt (magnified 10 times). 



Fig. C. A portion of the skin of the udder, showing the small ticks. From 

 a fatal case of Texas fever produced liy pla< ing young ticks on the 

 animal, (Natural size.) 



Fig. 7. A portion of the ear of the same animal, showing same full-grown 

 ticks ready to drop off. (Natural size.) 

 Plate XLYII. The cattle tick (Mnrrinropu-s iinnuJa-ltis) . 



I'^ig. 1. Dorsal view of male. (Greatly enlarged. (»riginal.) 



Fig. 2. Ventral view of male. (Greatly enlarged. Original.) 



Fig. 3. Forsal view of repleto female. (Greatly enlarged. Original.) 



Fig. 4. Ventral view of same. 

 Plate XLVIII. Portion of a steer's hide, showing the Texas fever tick {Mar- 



garopiis aiuiiildtuis). (Natural size. Original.) 

 Plate XLIX. Fig. 1. Tick-infested steer. 



Fig. 2. Dipping cattle to kill ticks. 

 Plate Ij. Map of the Fnited States, showing region infected with Texas 

 fever of cattle. The heavy line shows the lioundary of the tick-infested 

 area at the l)eginning of the work of tick eradication in 1000. AYhite 

 areas below the line sliow territory that has lieen freed from ticks and 

 released from quarantine. Sliaded areas remain tick infested and 

 under quarantine (April 1, lOlG). As a general rule, cattle may not be 

 shipped interstate from the sliaded area except for immediate slaughter. 

 As the f|uarantined area is subject to change at any time, this map 

 should be compared with the latest regulations, which may be obtained 

 at any time on application to the Seiretary of Agriculture. 

 .MI4 



