SYSTEMATIC AND DESCRIPTIVE. 133 



observed, and in six days the threads have broken 

 up into cocci. They were observed in the intestine 

 of fowls, especially in the contents of the vermiform 

 appendix. Inoculation of rabbits is followed by 

 negative results. 



Bacterium merismopedioides, Zopf. Forms 

 threads i 1*5 p in thickness ; these subdivide into 

 long rods, short rods, and finally into cocci. The 

 cocci divide first in one and subsequently in two direc- 

 tions, forming characteristic groups, which appear 

 like merismopedia. These groups may eventually 

 consist of 64 x 64 cells or more, and ultimately form 

 zoogloea. The cocci develop again into rods and 

 threads. They were observed in water containing 

 putrefying substances (River Panke, Berlin).* 



Bacterium pneumonias crouposse (Plate I., 

 Fig. 5). Cocci ellipsoidal and round, singly, in 

 pairs (diplococci), rods and thread forms. The cell 

 membrane thickens, and develops into a gelatinous 

 capsule, which is round if the coccus is single, and 

 ellipsoidal if the cocci occur in pairs or in rod 

 forms. Cultivated in a test-tube of nutrient gela- 

 tine it grows along the needle track in the form of 

 a round-headed nail (Plate IV., Fig. 2) without 

 liquefaction of the gelatine. The cocci when arti- 

 ficially cultivated have no capsule, but it again 

 appears after their injection into animals. The 

 coccus can also be cultivated on blood serum and 

 on boiled potatoes. They occur in pneumonic exuda- 



* Zopf, Die Spaltpilze, p. 66, 1885. 



