PROTOZOAN FAUNA OF HAY INFUSIONS 247 
ec. from the 36th to the 50th day in A JIT; and a maximum of 6500 
per cc. on the 23rd day in A IV. 
2. B Infusions 
Monad. In groups BI and B JI monads were practically 
absent. B III had none at the bottom during their presence 
at the top, but later a few were observed at the bottom from the 
35th to the 55th day. In B IV monads appeared in numbers be- 
Fig.8 BIV group. The ordinates represent the number of organisms at the 
surface. On the abscissa is plotted the number of days of the existence of the in- 
fusions. Monad = ----; Colpoda = —--—- ; Hypotrichida = —-—; Vor- 
ticella = — — - ; Amoeba = —.-- —. 
tween 500 and 100 per ce. from the 20th to the 35th day. Their 
appearance was coincident with the descent of paramaecia. It 
will be recalled that few monads were observed at the surface of 
the infusions of this group. 
Colpoda. Considerable diversity existed between the Colpoda 
in the B groups. In BI and B III they attained a temporary 
maximum of approximately 15000 per cc., just after their dis- 
appearance from the top (ef. fig. 13). In B IJ and B IV prac- 
tically none were seen at the bottom. 
