bo 
(5) 
os 
-LORANDE LOSS WOODRUFF 
4. Paramaecium 
A I group. Paramaecium appeared in considerable numbers 
about the 14th day and after various fluctuations in numbers 
reached a maximum of 1100 per ce. on the 51st day. This was 
sueceeded by a general decline in numbers to the 73rd day when 
only about 40 per cc. were present; but after this their number 
increased to about 700 per cc. on the 79th day and continued so to 
the end of the observations on the 86th day. 
A ITI group. The data for the paramaecia of these two cul- 
tures will be considered later, because the presence of Didinium 
so altered the paramaecium cycle that it cannot be fairly com- 
pared with that in the other cultures. 
A ITI group. Paramaecium made its appearance here on the 
7th day and gradually increased to its greatest abundance on the 
48th to 50th days, at which time about 3700 individuals per ce. 
were present. After this the number rapidly fell to 300 per ce. 
on the 64th day when the last count was made. 
A IV group. This organism appeared on the 4th day, attained 
the number of 2500 per ce. on the 31st day, and this maximum con- 
tinued for fourteen days after which there was an abrupt decline 
to about 50 per ce. on the 57th day, when observations were sus- 
pended. 
BI group. Paramaecium appeared on the 10th day, attained 
a low maximum of less than 100 per ec. on the 20th day and then 
very gradually reached extinction by the 65th day. 
B II group. This form was present in small numbers prac- 
tically from the start (8rd day) and reached a small maximum of 
about 160 per ce. on the 7th day, from which time they gradually 
decreased until they became extinct on the 24th day. This cul- 
ture also was influenced by the activities of Didinium, and this 
will be discussed later. 
BIII group. Paramaecium appeared on the 11th day, reached 
its maximum on the 17th day when 160 per cc. were counted. 
From this time to the 65th day, when the last count was taken, 
it continued to persist in varying numbers under 100 per ce. 
