PROTOZOAN FAUNA OF HAY INFUSIONS 235 
BIV group. The cycle of Paramaecium will not be considered 
at this time as it was so altered by Didinium that it is not at all 
comparable with that of the other cultures. 
CI group. Paramaecium appeared on the 21st day, gradually 
multiplied until 600 per ec. were counted on the 40th day, then 
increased rapidly to 2500 per ec. on the 45th day, fell to 1200 per 
ec. on the 48th day, and to 200 per ce. on the 61st day. From 
this time there was a gradual decline to the last count on the 86th 
day, when about 80 per cc. were present. 
C III group. In this group, comprising but a single infusion, 
paramaecia appeared on the 23rd day, increased to about 440 
per ce. on the following day and fell in number until only about 10 
per ce. were observed on the 34th day. From this point they 
Fig.4 A JV group. The ordinates indicate the number of organisms per cc. 
at the surface. On the abscissa is plotted the number of days of the existence of 
the infusions. Monad =. -- -; Colpoda = —--—-; Hypotrichida = — - —; 
Paramaecium = ; Vorticella = — — - ; Amoeba = — - - —. 
