536 VARIOLA 



of the softening of the nodule the body temperature rises to 

 39.5-40.6°, later to 41.5-42.6° as a sign of the entrance of the 

 virus into the circulation, in consequence of which nodules 

 form on the mucous membrane of the lips, around the nose 

 and eyelids, later also in the axillary region, on the thighs, in 

 the pubic and anal regions. Later these form into pock vesicles. 

 At the same time the general symptoms of fever reach a high 

 grade until at the beginning of the third week after infection 

 or perhaps later death follows with symptoms of septicemia. 

 After subcutaneous infection the temperature rises with the 

 beginning of the local inflammation ; the latter consists of a 

 hard swelling the size of a fist, with countless nodules, later 

 with pock vesicles running together on the surface, while the 

 pock eruption generally follows on the 5th or 6th day after the 

 infection and in a manner similar to that after cutaneous 

 inoculation. Intraperitoneal injection of the lymph results 

 directly in the formation of nodules on the peritoneum with 

 swelling and painfulness of the abdomen, a specific inflamma- 

 tion of the mucous membrane of the trachea with exceedingly 

 difficult breathing, to which is generally added a general pock 

 eruption on the 6th or 8th day (Bosc) . Injection of the lymph 

 into the circulation generally causes a rise of temperature 

 without skin eruption, but though the disease is slight and of 

 short duration the sheep become as immune as after surviving 

 the typical disease (Semmer and Raupach ) . After intracerebral 

 inoculation fever occurs after 6 or 8 days, upon which the 

 animals die within a week, while injection of the lymph into 

 the lactiferous duct causes a pock eruption on the mucous 

 membrane of the udder and the milk contains the infective 

 material for two weeks (Nocard). 



Natural infection. The contagion of sheep pox, which 

 usually comes in the form of a general disease, according to all 

 probability reaches the lungs with the inspired air and here 

 passes from the alveoli directly into the blood, by which it is 

 carried to the superficial vessels of the skin and mucous mem- 

 brane. By injection or spraying of the pock lymph into the 

 trachea of susceptible sheep the disease is sure to be reproduced. 



Digitized by Microsoft® 



