MICROCOCCI PATHOGENIC IN MAN. 185 



staphylococcus grows on potatoes in the form at first of 

 a bright yellow, and later of a thick soft golden yellow 

 layer. When inoculated into milk, coagulation occurs 

 after one to eight days in consequence of the production 

 of one or several acids, among which lactic acid has the 

 preponderance. A peculiar sour smell also becomes 

 evident after some time in the cultivations on potatoes 

 or agar. 



The yellow colouring matter is only formed where Products of 

 the colony is in contact with free air ; under a layer of gl 

 oil the cultivations remain white. It is probable from 

 the peculiar and energetic action of the fungus on the 

 living tissue of warm-blooded animals that poisonous 

 irritating materials are produced, and hence it would be 

 very desirable to obtain a more accurate knowledge of 

 the products of their growth. Brieger has recently 

 (Weitere Untersiichungen uber Ptomaine, p. 73) iso- 

 lated an organic base from staphylococcus which had 

 been grown in meat infusion. This base does not appear 

 to be identical with any of the ptomaines as yet known, 

 and thus seems to be a specific product of the growth of 

 the staphylococcus ; it did not however prove to be 

 poisonous to the animals experimented on. 



The staphylococcus is remarkable on account of its 

 relatively great resisting power to external agents ; the 

 cultivations in gelatine or agar are active after more 

 than a year. 



The action of the staphylococcus on animals varies Action on 

 greatly according to the mode of application. Subcu- ai 

 taneous inoculation is without result in mice, guinea- 

 pigs, and rabbits ; when inoculated on the cornea of 

 rabbits a small greyish white infiltration occurs, accom- 

 panied by inflammation which subsides on the fourth day. 

 After subcutaneous injection the pyogenic properties of 

 the fungus become evident. It is only in mice, and after 

 the injection of relatively large quantities, that death 

 occurs early ; in guinea-pigs and rabbits, on the other 

 hand, an abscess forms in the first instance, and this 

 can either heal and the animal recover, or a general 

 infection may ultimately occur. Intraperitoneal and 



