No. 4.J REPORT OF CATTLE BUREAU. 315 



and the lesion is evidently due to cocci, which it will be remem- 

 bered were found in large numbers in the pustules of cow No. 5, 

 which lesions were used for the inoculations. 



Vaccination of Cows. 



The following experiment was undertaken in order to ascertain 

 whether or not the cows that had passed through the disease in 

 question were immune to vaccinia : — 



Experiment No. 4: Sept. i<9, 1903. — Cows Nos. 1 and 3 were 

 vaccinated with commercial vaccine lymph. Both were killed 

 three days after. Several small papules were found at the site of 

 inoculation in each cow. Microscopical examination shows in both 

 cow No. 1 and cow No. 3 typical early vaccine lesions. These 

 lesions present the vacuolar degeneration of the epidermal cells 

 and the parasitic protozoan cytoryctes peculiar to vaccinia. 



Summary. — The mouth lesions and the vesicles occurring on 

 the udders present a special type of necrosis, and represent a 

 process entirely distinct from vaccinia. 



The pustules obtained from cow No. 5 showed nothing indica- 

 tive of vaccinia, but contained cocci in large numbers. Other 

 pustular lesions represent suppuration about hair follicles. 



The inoculation of rabbits' corneas with lymph from various 

 lesions gave in all cases negative results, eliminating the possi- 

 bility of vaccinia. 



Two cows having passed through the eruptive disease described 

 in this report were not immune to vaccinia, as has been shown by 

 the inoculation of vaccine lymph and the subsequent microscopical 

 study of the lesions. 



In conclusion, it may be stated that no evidence of the presence 

 of vaccinia in the diseased cows has been obtained either through 

 experimental inoculation or through histological study of the vari- 

 ous lesions. Lesions developing at the points vaccinated have 

 been studied from both the calves vaccinated on July 31 on G. R. 

 Tyzzer's estate, and from the calves vaccinated August 28 on the 

 Newcomb estate. They all show a typical vaccine process. The 

 fact that tlie calves inoculated on the Newcomb estate did not die, 

 as did those inoculated four weeks earlier on the Tyzzer estate, 

 may possibly be accounted for either by their age causing them to 

 react in a different manner to the disease, or b}' the attenuation 

 of the virus while being kept for four weeks on the ice. 



It is evident, from the experiments carried on at the Newcomb 

 estate, that a disease characterized by a rise of temperature, vesi- 

 cles of the mouth, feet and udders, and which cannot be distin- 



