118 PRINCIPLES OF VETERINARY SURGERY 



this genus of the coccaceas in the production of disease is 

 largely a matter for future investigation. That streptococci 

 produce various diseases in which different forms of the ge- 

 nus are the specific causes, is not questioned. From time to 

 time, as investigations proceed, different forms are recog- 

 nized as the specific causative agents of certain diseases. For 

 example the diplococcus of pneumonia (once described as a 

 streptococcus) is now recognized as having a potent influ- 

 ence in provoking inflammations in the lungs ; the strepto- 

 coccus erysipelatis, is no longer doubted as the specific mi- 

 crobe of human erysipelas ; and the streptococcus equi 

 (Shultz) is believed to be the cause of equine strangles The 

 forms described under the single name of streptococcus pyo- 

 genes include all the varieties that are capable of producing 

 suppuration. Pus taken from different lesions does not al- 

 ways exhibit the same arrangement of the chains, which fea- 

 ture is much depended upon for differentiation. It is there- 

 fore evident that various forms of streptococci are pyogenic. 

 It is even shown the streptococcus erysipelatis can not be dif- 

 ferentiated from the streptococcus found in abscesses. 

 Speaking along this line Moore says: "The study of strepto- 

 cocci from various sources, more especially from the tissues 

 of diseased animals, suggests the, desirability of delaying 

 a further classification until more definite data are obtained 

 concerning the natural history, not only of these, but also 

 of the species normally present on the mucous membranes 

 of animals, and in nature generally." The specific name is, 

 pathologically or even biologically speaking, of little mo- 

 ment unless we can attach a certain definite meaning to it 

 concerning the morphologic characters, culture manifesta- 

 tions and the degree of disease-producing power possessed 

 by the organism designated." 



The streptococcus pyogenes, of Rosenbach, which name 

 we shall use for the purpose of describing the pus-producing 



