DIPLOCOCCUS CORYZ.E 265 



arranged in fours, and was discovered by Von Besser in 

 the normal mucus of the nose. No growth takes place 

 upon gelatine, but it develops well on agar and potato. 

 The older cultures have a yellowish-brown colour. 



Micrococcus nasalis. — Hack encountered in the naso- 

 pharyngeal cavity motile diplococci, the growth of which 

 does not liquefy gelatine. The islets on the gelatine plate 

 show a small undulating excavation in the centre, and in 

 individual colonies it is easy to recognise a radiating 

 arrangement or coiled form, frequently with a rayed 

 margin. A concentric stratification of the superficial layer 

 is often seen in thrust-cultures, together with development 

 of nodules along the thrust-canal. A greyish-white shining 

 deposit forms upon agar and potatoes. 



Diplococcus coryzae. — This diplococcus was described by 

 Hajek, who found it in the nasal secretion. It consists of 

 cocci which are somewhat elongated, so as to look like 

 short bacilli. Gelatine is not liquefied by them. Flat 

 superficial-lying colonies develop on the gelatine plate, and 

 on thrust-cultures a deposit forms, which is at first raised 

 but becomes continually more and more flattened out, a 

 fact which serves to distinguish the culture of Diplococcvs 

 coryziB even by the naked eye from Friedlander's Pneumo- 

 hacillus, since no alteration takes place in the nail-culture 

 formed by the latter. A coating develops upon agar. 



This diplococcus was at first regarded as the exciting 

 cause of those changes in the mucous membrane which are 

 characteristic of coryza. Experiments on animals, however, 

 have yielded results which are negative in this respect. 



Staphylococcus cereus aureus. — This microbe resembles 

 the Staphylococcus cereus fiavus, only differing from it in the 

 orange-red colour of its colonies, which is particularly marked 

 in thrust-cultures. It was discovered by Von Schrotter and 

 F. Winkler in the author's Institute, in the thin secretion 



