LS) 
Or 
PROTOZOAN FAUNA OF HAY INFUSIONS Di 
A-1, A-2, A-3, A-4, A-5, A-6, averaged and designated A J 
A-21, A-22 averaged and designated A JI 
A-31, A-32 averaged and designated A I/T 
A-41, A-42 averaged and designated A JV 
B-1, B-2 averaged and designated B J 
B-21, B-22 averaged and designated BIT 
B-31, B-32 averaged and designated B JIT 
B-41, B-42 averaged and designated BIV 
C-1, C-2, C-3 averaged and designated C J 
C-31 designated OP JUUE 
C-41, C-42 averaged and designated C IV 
This method of treating the data was decided upon because it 
gives, it is believed, the fairest picture of the protozoan sequence 
in the infusions. As a matter of fact the individual infusions of 
the respective groups presented comparatively unimportant 
variations—except in certain cases which are mentioned. Three 
of the six infusions composing group A J were discontinued at the 
end of the first month because the variations between the indi- 
vidual infusions was not sufficient to warrant the study of so 
many. For a record of the surface sequence of a single infusion, 
reference should be made to C JI/ (fig. 10). For the data of a 
single form (Paramaecium) at the bottom of two infusions com- 
prising a single group, see fig. 12. 
D. TIME OF APPEARANCE, MAXIMUM NUMBER AND DISAPPEARANCE 
OF REPRESENTATIVE PROTOZOAN FORMS AT THE SURFACE OF 
THE INFUSIONS 
1. Monad 
A I group. Monads were the first animals to appear in con- 
siderable numbers and their maximum was attained on the 7th 
day when there were about 5200 per cc. Their decline was equally 
rapid and by the 20th day of the life of the infusions none were 
observed in the samples studied. 
A ITI group. These forms were the first to appear, reach their 
maximum of 2000 per cc. on the 4th day, and miminum on the 
Sth day. 
