152 PATHOGENIC BACTERIA. 



In the characteristics of its growth the Staphylococcus 

 albus is almost identical with the species next to be de- 

 scribed, but differs from it in that there is no golden 

 color produced. Upon the culture-media it grows white. 



Generally present upon the skin, though in smaller 

 numbers, is the dangerous and highly virulent Staphylo- 

 coccus pyogenes aureus (Fig. 44), or " golden Staphylococ- 

 cus" of Rosenbach. As the morphology of this organ- 

 ism, and indeed the generality of its characters, are 

 identical with those of the preceding species, it seems 

 convenient to describe them together, pointing out such 

 differences as occur step by step. In doing this, how- 

 ever, it must not be forgotten that, although the Staphy- 

 lococcus albus has been described first, the Staphylococcus 

 aureus is the more common organism of the suppurative 

 diseases. 



Although they had been seen earlier by several ob- 

 servers, the staphylococci were not isolated and care- 

 fully described until 1884, when Rosenbach worked upon 

 them. The results of his study, followed by Passet and 

 a host of others, have now given us pretty accurate 

 information about them. 



The cocci are distributed rather sparingly in nature, 

 seeming not to find a purely saprophytic existence a 

 suitable one. They occur, however, wherever man and 

 animals have been, and can be found in the dust of 

 houses, hospitals, and especially surgical wards where 

 proper precautions are not exercised. They are common 

 upon the skin, they live in the nose, mouth, eyes, and 

 ears of man, they are nearly always beneath the finger- 

 nails, and they sometimes occur in the feces, especially 

 in children. 



The cocci are rather small, measuring about o. 7 p in 

 diameter. When examined in a delicately-stained con- 

 dition the organisms may be seen to consist of hemi- 

 spheres separated from each other by a narrow interval. 

 The contiguous surfaces are flat, thus differing from 

 the gonococcus, whose contiguous surfaces are concave. 



