" braxy " sheep disease in australia. 601 



Summary and Conclusions. 



1. A group of diseases of sheep exists in various parts of the 

 world, which though not absolutely identical are so closely allied 

 that they may be dealt with under one general term — Braxy. 



2. The diseases of this group already investigated, at least 

 partially, are " braxy " in Britain, " bradsot " in Norway and Ice- 

 land, " braxy-like disease " in New Zealand, " hogget disease " in 

 Tasmania, and a disease of sheep in Victoria, Australia. 



3. The diseases are alike in that young sheep, especially those 

 in good condition are prone to attack. Seldom are symptoms 

 observed, the course being rapid and early fatal, the pathological 

 lesions are in the main identical, post-mortem putrefaction is very 

 rapid, the nature is endemic, the occurrence is seasonal, recovery 

 (if such occurs) is extremely rare, and they are due to anaerobic 

 gas-producing bacteria. 



4. Experimentally the pathogenic lesions of the disease can be 

 readily reproduced by effusions and morbid products containing the 

 bacilli, and by pure cultures, when injected into the subcutaneous 

 tissues, but ingestion experiments are generally, if not always,, 

 unsuccessful. 



5. In the above paper the diseases as appearing in Tasmania 

 and Victoria (Australia) are especially studied, but a summary of 

 investigations on the other diseases is also given. 



6. The causative organism studied here is an anaerobic ?poru- 

 lating bacillus morphologically similar to that of blackleg, the 

 chief distinguishing cultural characteristic being the bi-convex,. 

 disc-like colonies in agar media. 



7. The most convenient method of cultivating the bacilli after 

 isolation is to place in broth or serum broth media a small portion- 

 of dried m sole containing spores, exclusion of the air being un- 

 necessary. 



8. The Tasmanian and Victorian diseases, though similar in 

 all essential details, yet differ in minor points, such as seasonal and 

 age incidence (the former occurring in winter and practically con- 

 fined to yearlings, the latter occurring in summer and practically con- 

 fined to two-year-olds), in the virulence for cattle and rabbits, and 

 in some slight morphological and cultural characters of the patho- 

 genic bacilli. 



9. That the diseases are but varieties of the one is, however, 

 definitely proved by immunity to one implying immunity to the 

 other. 



10. Cultivations of the pathogenic bacilH (at least those studied 

 here) in glucose broth results in a rapid though gradual weakening 

 of virulence. 



11. By the use of such weakened cultures immunity may be 

 produced, but experiments in the field are required to ascertain i£ 

 such a method may be used economically and with safety. 



