i8 



Incubative Period 



My experience is that this may be put down as 

 anything varying from three weeks to three months, 

 and it may extend to six, eight, or ten months, and 

 even more ; in tact, I have one case on record which 

 had an incubative period of over thirteen months. I 

 have also a few cases on record in which the disease 

 recurred after being apparently cured, but in none of 

 these did the second incubative period exceed one 

 month ; still there appears to be no reason why the 

 incubative period for recurrent cases should differ very 

 much from that of ordinary ones, and Cranford, writing 

 from India, records a case which recurred after fourteen 

 months (Veterinary Record^ June 4, 1904). 



In my experimental cases the first symptoms of the 

 disease (viz., a nodule) appeared after thirty-two days, 

 with pustules bursting on the fifty-third day ; mode of 

 inoculation being subcutaneous. Mettam, experiment- 

 ine^ on the disease, recently, informs me that he did not get 

 the nodular symptoms until after forty days, that pustules 

 formed and burst five days afterwards, and that the lesions 

 had all healed again and disappeared in a couple of weeks' 

 time after the pustules burst, but that now (ist April, 

 1904), three months afterwards, the nodules are re- 

 appearing. The mode of inoculation in this case was 

 scarification made in two separate places, one on the near 

 side of the neck which took, and another on the off 

 quarter which up to date shows no sign of the disease. 



Tixier, Delamotte, and Chauvrat by puncture and 

 scarification got pustules in from twenty to sixty-six 

 days. Delamotte and Peuch state the period in donkeys 

 is a month or more. 



Wiart gives the period as eight days to five or six 

 months. 



Quiclet has seen it take eighty-nine days to develop, 

 and Tokishige makes no attempt to specify any time. 



