184 APPLIED BACTERIOLOGY 



by various observers in dust, earth and water, but its pre- 

 sence in these is probably accidental. The thermal death- 

 point of the organism is given at 58° C. by Sternberg, pro- 

 vided the organism is in a moist condition ; if desiccated, 

 he finds that much greater heat is essential to ensure its 

 destruction. 



Pathogenesis. — The result of an injection of the organism 

 into animals seems to be largely governed by the size of the 

 dose, large doses being fatal, while small ones are without 

 result. 



Experiments on the human subject by various observers 

 show that the inoculation of the organism is always 

 followed by the production of a local lesion in which the 

 staphylococcus may be recognised, and which heals up after 

 a few weeks. The organism has been found in ulcerative 

 endocarditis and in infective osteo-myelitis, and in a great 

 number of inflammatory lesions and abscesses in every part 

 of the body. 



The Streptococcus pyogenes is dealt with under Erysipelas. 



Staphylococcus Pyogenes Albus. — This organism occurs 

 less frequently than the foregoing, but in all respects, with 

 the exception of its colour, is not to be distinguished from 

 it. It liquefies gelatine, and behaves in a similar manner 

 to the Staphylococcus pyorjeues aureus in every respect. 

 Welch (quoted by Sternberg) is of opinion that, as its patho- 

 genic properties are more feeble than those of the foregoing, 

 the name Staphylococcus epidermidis albus is preferable, as he 

 considers it hardly deserves the qualification of ' pyogenic' 

 He finds it to be the most frequent inhabitant of the skin, 

 and to be so deeply buried in the epidermis as to render 

 it impossible to be attacked by any of our present means 

 of disinfection. It is the most frequent cause of stitch- 

 abscess. 



Other organisms belonging to this group are the Staphy- 



