GEOGRAPHICAI, DISTRIBUTION 205 



by Lebert and Robin both of whom failed to recognize it as a 

 vegetable parasite. 



The fungus was carefullj' described by Dr. Harz, a botan- 

 ist, who gave it the name actinomyces or ray fungus. Bol- 

 linger was the first to carefully study the disease in cattle and 

 to demonstrate the power of the ray fungus to produce dis- 

 ease. With this discovery of Bollinger in 1877, actinomycosis 

 became recognized as a definite, specific disease which could 

 in most cases at least be differentiated from the other affec- 

 tions with which it had hitherto been confused. In 1845, von 

 Langenbeck of Kiel observed and made drawings of peculiar 

 bodies in a case of vertebral caries in man which it is now be- 

 lieved were rosettes of the raj' fungus. In 1878 Israel demon- 

 strated the disease in man. Since that time it has been care- 

 fully studied and described by a number of investigators. 



§ 162. Geographical distribution. Actinomycosis is 

 quite widely distributed throughout North and South America 

 and Europe. It is much more prevalent in certain countries 

 and districts than in others. The observation has been made 

 that animals pastured upon low lands and in river valleys are 

 more liable to contract it than those feeding upon high and 

 dry ground. It has also been noted that cattle fed upon 

 rough or coarse forage are more prone to the disease on 

 account of abrasions of the buccal mucosa than those kept 

 upon less harsh food. 



It is very difficult to procure reliable statistics concerning 

 the extent to which it occurs. The observations, which have 

 been made at the union stock yards, Chicago, show one case 

 of actinomycosis in from 1600 to 1700 cattle. The statistics 

 from the abattoirs in Berlin show one case to 4250 cattle and 

 one in 8000 pigs. These figures do not, however, indicate the 

 extent of the disease among the farm animals as they are col- 

 lected from those animals presented for slaughter only. At 

 the clinic of the New York State Veterinary College there is 

 presented for treatment a very few cases each year. In the 

 Mississippi valley and in the south-west it seems to be more 

 prevalent than it is east of the Alleghany Mountains. 



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