Dourine. 523 



without local lesions or propagation of the parasite in the blood. 

 The same blood inoculated after 15 days produced neither local 

 lesion nor fever. 



Lesions. Horse. In the early stages are found a phlegmonous 

 or oedematous swelling of the sheath, scrotum, penis and inguinal 

 glands and a yellowish liquid effusion into the scrotal cavity. 

 The skin covering these parts may .show a papular or vesicular 

 eruption or if this has passed, a mottling with white spots shows 

 where the lesions have been. L,ater still the inguinal glands are 

 shrunken and have undergone fibroid degeneration and" indura- 

 tion and the testicles, swollen or .shrunken, contain centres of 

 caseation. The connective tissue of the epididymus and cord is 

 the seat of a gelatinoid exudation. The walls of the scrotum may 

 be greatly thickened and the seat of abscess or of caseous degen- 

 erated hyperplasia. In advanced cases the testicles are usually 

 abnormally small even if the scrotal mass is enormously dis- 

 tended. The sheath and penis may be the seat of more or less 

 numerous ulcers, and swellings, contractions and distortions of 

 the latter organ are not uncommon. The penis may, however, 

 retain its normal dimensions. The walls of the lymphatics in the 

 inguinal region may be the seat of hyperpla,sia, the thickening 

 causing them to stand out like cords as in glanders. In the ad- 

 vanced stages the muscles, especially those of the hind limbs, be- 

 come pale and atrophied. 



The nerve centres undergo profound changes which have been 

 studied by Thanhoffer. The pia m,ater in the affected parts of 

 the spinal cord is the seat of active congestion and thickening. 

 The central canal of the cord is dilated (syringomyelia) more at 

 one point than another, contains more than the normal amount 

 of liquid, and the neuroglia around it is thickened and fibrous 

 (sclerosed). The substance of the cord, both white and gray, 

 shows congestion, blood staining, at points foci of softening, and 

 at others induration (hyperplasia of the neuroglia). The w^rwe 

 cells are modified in various ways, some being granular, some dis- 

 colored by fine granular pigment, some having enlarged and mul- 

 tiplied nuclei, and some show vacuoles. The nerve filaments 

 often show a granular degeneration extending from the nerve 

 cell into the axis cylinder, and the latter is liable to be varicose 

 or uneven in size. In the affected portion of the cord leucocytes 



