188 CLASSIFICATION OF THE MICRO-ORGANISMS. 



quently in man than aureus ; according to Rosenbach, on 

 the contrary, less frequently, and usually mixed with 

 aureus. In many animals (rabbits) the staphyl. albus 

 seems to be decidedly the most frequent. 



* 



Staphylococcus pyogencs citreus. 



Found by Passet in a few cases (in 10 per cent, of the 

 cases) in the pus of acute abscesses. Differs from the 

 foregoing only in the bright citron yellow colour of its 

 cultivations, the difference as contrasted with the dark 

 yellow orange-coloured pigmentation of staphyl. aureus 

 being distinctly evident, especially in old cultivations. 



Micrococcus of the " Clou de Biskra " 



By the term "Clou de Biskra, or Bout on d'Alep/' 

 is meant an endemic disease occurring in Aleppo, Bagdad, 

 Biskra, and Tunis, characterised by tubercular swellings 

 on the face and extremities, which develop in the course of 

 a year, burst, and finally cicatrise. Duclaux has found 

 micrococci in the blood of these patients, which were less 

 than 1 n in diameter, occur in the form of diplococci or 

 zooglaea (thus belonging to the staphylococci), and can be 

 cultivated in neutralised veal infusion. Twenty drops of 

 the cultivation injected subcutaneously into rabbits excite 

 extensive gangrene, but the animals ultimately recover. 

 Large doses injected into the blood of rabbits kill them 

 within 16 hours, and on post-mortem examination peri- 

 carditis, pleuritis, haemorrhagic infarcts in the lungs, &c., arc 

 found. After the intravenous injection of small doses, a 

 chronic disease, which gradually gets well, begins after an in- 

 cubation period of 10 days ; this disease is characterised by the 

 occurrence of numerous small ulcerating nodules distributed 

 over the skin of the whole body, and recalling exactly the 

 disease in man. A confirmation of this observation by the 

 investigation of other cases of Clou de Biskra must be 

 awaited. 



Duclaux has made a striking observation with regard to 

 the cultivations of these micrococci. Old cultivations gra- 

 dually lose their virulence, so that after standing for two 

 months the cultivations were inactive, even in large doses. 

 But if fresh infusion was inoculated from these old inactive 

 cultivations, the new cultivation was as virulent in the first 

 few days as the former young cultivations, and according to 

 the dose employed it set up the whole series of morbid symp- 



