PNEUMOCOOCUS 271 



golden-yellow colour, while a thick golden-yellow layer 

 grows on potato. 



Diplococcus pneumoniae. — Klebs and Eberth long ago 

 pointed out the presence of cocci in croupous pneumonia, 

 while A. Frankel and Weichselbaum have studied them with 

 the help of the modern methods of research, and ascertained 

 that the cause of this affection is a micrococcus which Weich- 

 selbaum detected in ninety-one cases out of a hundred. 



These cocci are round or sometimes elongated, and 

 possess a jelly-like envelope of varying thickness. They are 

 very often found arranged in pairs, and it is not unusual 



for several such diplococci ^-. , _ , . =, 



to be connected in rows, ^ ° ' I^T ' 'I) *' *» ^u '" '' 

 one behind the other, and t -J* »?^ ^' ^^ ** j^ M^ => 

 enclosed in a common cap- ' "^t. • i, 

 sule (fig. 94). Motility is ^ * " :' ^, I 



absent. i\ _ i «^ ' ^ 



if Si **' V^^" 



These cocci occur in t^)' 



croupous pneumonia not " J \^ 

 only in the sputum and in „ ' - i_ '^ 



the diseased lung, but also j,,„. 94.-micboees o.. PNEmioxiA. 



in the blood, and they are ^'''*'' ^'^'^'^ 



met with in different other diseases. According to Weich- 

 selbaum they are found in exudations in the cavum tympani 

 and in the ethmoidal labyrinth, and Foa and Bordoni believe 

 them to be the sole cause of cerebrospinal meningitis. 

 Klein, Biondi, A. Frankel and Miller found them also 

 in the buccal and naso-pharyngeal cavities of healthy 

 individuals, so that they can exist as it were in the portals 

 of entrance to the respiratory system. They are iden- 

 tical with the microbes of sputum septicemia. Emmerich 

 found them in the dust of a room occupied by pneumonic 

 patients. 



Their growth begins to make good progress at a tern- 



