438 Dl^EAbES OF CATTLE 



TEXAS FEVER. 



[Description of plates.] 



PLATE XLII. Fig. 1. Spleen of an acute fatal case of Texas fever. The narrow 

 end of the spleon 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| pounds, was nearly three times that of the healthy spleen, 2| pounds. 



PLATE XLJII. Showing the cut surface of a healthy liver taken from a steer 

 slaughtered for beef. Fig. 2. Showing the cut surface of the liver in Texas fever. 

 Fig. 3. Represents the appearance of the urine in an acute fatal case of Texas fever. 

 Fig. 4. Shows red corpuscles, magnified a thousand diameters, containing the par- 

 asite of Texas fever. This appears as a blue point, a, near the edge of the corpuscle. 

 The blood was taken from a skin incision. The case was non-fatal and occurred late 

 in fall. Fig. 5. Shows red corpuscles from the blood of an acute fatal case, tweuty 

 hours before death. The Texas fever microbes, , 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. Magnified 

 a thousand diameters. 



PLATE XLIV. The cattle tick, 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, magnified 

 10 times. Fig. 5. The female after the last molt, magnified 10 times. Fig. 6= A por- 

 tion of the skin of the udder, showing the small ticks. From a fatal case of Texas 

 fever produced by placing young ticks on the animal. Natural size. Fig. 7. A por- 

 tion of the ear of the same animal showing same full-grown ticks, ready to drop off. 

 Natural size. 



