554 



Journal of Agricultural Research 



Vol. IV, No. 6 



manner there is no correlation between the multiplication of the differ- 

 ent protozoa (all types) in the different infusions inoculated with the 

 same soil and incubated at the same temperature. For nearly all inoc- 

 ulations the greatest multiplication of the flagellates is noted at 22° to 

 23° C. In some solutions the small ciUates multiplied faster at 15° to 

 16°, in others at 22° to 23°, and in still others at 29° to 30^^ C. 



Table XII. — Rate of multiplication of the protozoa in culture solutions from the time of 

 their first appearance tmtil the first increase uas noted. This period was usually 24 

 hours 



INCUBATED AT 6 TO 7° C. 



II2I 



II22 

 II23 

 II24 

 II25 

 II26 



"31 

 II32 

 II33 

 1 134 



"35 



1 136 



1141 

 1142 

 "43 

 1144 

 I145 

 1146 



INCUBATED AT 15 TO 16° C. 



148. 



INCUBATED AT 22 TO 23 C. 



2-3 



588.0 



o 



2- S 

 8.0 



3-3 



136. 

 ,408. 



INCUBATED AT 29 TO 30" C. 



6. 

 259- 



3-0 

 380.0 



If in the future study of soil protozoa quantitative determinations are 

 to be made, definite standards of quantity and of certain character 

 (moist or dry) of soil must be taken in order that all the results will be 

 comparable. Likewise, a definite standard of inoculation temperature 

 and the kind of culture media must be fixed. The time at which the 

 examinations are made must be uniform. 



In so far as the data presented in Parts II and III show on the gram 

 basis the greatest development of certain types of small ciliates, large 

 ciliates, and flagellates is secured from i-gm. inoculations in lOO c. c. of 

 solution. However, 5 gra. of soil would be more representative than 

 I gm; and, as shown by Cauda and Sangiorgi (2), on the gram basis 



