334 BACTERIA PATHOGENIC TO MAN 



in the production of pysemia in the various pathological forms of 

 that condition of disease. It is remarkable how many staphylococci 

 may he p esent in the blood without a fatal result, if the original source 

 of infection is removed. We met with one case in which over 800 

 staphylococci were present in 1 c.c. of blood. A week later only five 

 were found. The patient finally died from pneumonia. 



Not all persons are equally susceptible to infection by the staphy- 

 lococcus; those who are in a cachectic condition or suffering from con- 

 stitutional diseases, like diabetes, are especially predisposed to infec- 

 tion. In healthy individuals certain parts of the body, as the back of 

 the neck and the buttocks, are more liable to be attacked than others, 

 with the production of furuncles, carbuncles, etc. In persons in whom 

 sores are readily caused, in consequence of disturbances of nutrition, 

 as in exhausting diseases, the micrococci settle at the points of least 

 resistance. Such conditions are present in the bones of debilitated 

 young children, in fractures, and injuries in general. 



The pyogenic properties of the staphylococcus have been demon- 

 strated upon man by numerous experiments. Garre inoculated a small 

 wound at the edge of one of his finger-nails with a minute quantity of 

 a pure culture, and purulent inflammation, extending around the mar- 

 gin of the nail, resulted from the inoculation. Staphylococcus aureus 

 was recovered in cultures from the pus thus formed. The same observer 

 applied a considerable quantity of a pure culture obtained from this 

 pus third generation to the unbroken skin of his forearm, rubbing 

 it well into the skin. At the end of four days a large carbuncle, sur- 

 rounded by isolated furuncles, developed at the point where the culture 

 had been applied. This ran the usual course, and it was several weeks 

 in healing. No less than seventeen scars remained to testify to the 

 success of the experiment. 



Staphylococcus Pyogenes Albus. 



It is morphologically identical with the staphylococcus pyogenes 

 aureus, and is probably the same organism which has lost the property 

 of producing pigment. On the average it is somewhat less pathogenic 

 and seldom produces pyaemia or grave infections. The surface cul- 

 tures upon nutrient agar and potato have a milk-white color. Its 

 biological characters are not to be distinguished from the staphylo- 

 coccus aureus. 



The majority of bacteriologists agree with Rosenbach, that the 

 aureus is found at least twice as frequently in human pathological 

 processes as the albus. 



Staphylococcus Epidermidis Aibus (Welch). 



Probably identical with the staphylococcus pyogenes albus. With 

 reference to this micrococcus, Welch says: "So far as our observations 

 extend and already they amount to a large number this coccus may 



