APHTHA THRUSH. 225 



inquiries as have from time to time engaged our attention. 

 The fact cannot, however, be lost sight of that the presence of 

 this disorder in lambs rarely or ever exists alone, but is mostly 

 attended with a form of inflammation of the udder of the dam, 

 which, on account of its destructive effects on the gland, has 

 been designated malignant or gangrenous mammitis. 



This disorder prevailed to some extent in the ewe flocks of 

 Lincolnshire during 1889, and proved very fatal to both lambs 

 and ewes. 



The fact that it is communicable from the diseased mouth of 

 the lamb to the teats and udder of the ewe, clearly establishes 

 its contagious nature, and M. Nocard, who has studied the 

 micro-pathology of the affection in the latter, avers that it is 

 due to a minute organism or micrococcus, which he has found 

 not only in the milk but also in the watery effusions present in 

 the abdominal cavity after death. 



That this organism is the specific cause of the disease in 

 shown by its capability to induce the affection in previously 

 healthy stock, whether inoculated with the milk itself or after 

 being separated from it by the usual methods of cultivation. 

 Professor Brown, of the Agricultural Department, when study- 

 ing the disorder as it occurred in the Lincolnshire outbreak, 

 has recognised in the diseased tissues of the lamb, a microbe 

 in every respect similar to that discovered by M. Nocard in the 

 ewe. 



It is therefore evident that the disease as it occurs in parent 

 and offspring is the same, and apparently the work of the same 

 micro-organism. 



In our experience, the lambs have invariably given evidence 

 of the disease first, and afterwards the ewes have appeared to 

 become inoculated from the mouths of their young ; but as to 

 the source from whence the lambs receive the infection, that is 

 a question still waiting solution. 



Is the materies morbi primarily contained in and given out by 

 the milk of the dam, or is it only after the teats become 

 inoculated by the lamb that it gains entrance to the gland ? 

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