540 Journal of Agricultural Research voi. iv, no. e 



development, as only a few appeared with some of the inoculations on 

 the seventh to the eleventh day after inoculation. In hay infusion, 

 however, they began to appear on the third day; the maximum numbers 

 were reached on the fifth to the sixth day after inoculation; then the 

 numbers decreased. 



DEVELOPMENT OF FLAGELLATES 



That there were more flagellate cysts in the soils examined or that the 

 media employed were more favorable for the development of these 

 organisms than for ciliates is clearly seen by the fact that in all the 

 culture solutions these organisms were more numerous. There was a 

 great variation in the development of these organisms in the different 

 solutions when inoculated with different soils. Upon noting the develop- 

 ment of these organisms from field soil it is seen that in the dried-blood 

 extract they appeared the first and second days after inoculation, the 

 maximum number being reached on the third and fourth days. In hay 

 infusion they appeared the second and third days; the maximum num- 

 bers were present from the sixth to the eighth day. 



In inoculations of both media with greenhouse soil the flagellates ap- 

 peared on the first day, the greatest numbers appearing from the second 

 to the fourth day in the blood extract and from the third to the eleventh 

 days in the cases of the inoculated solution of hay infusion. In com- 

 paring the period of maximum development of flagellates from the 

 various compost soil inoculations, it is seen that with large amounts of 

 soil inoculations the greatest development was attained several days 

 before the maximum had been reached with the smaller inoculations. 

 In total numbers of organisms developing there was no greater majority 

 from either soil examined. In some solutions of dried-blood extract 

 and hay infusion the greatest numbers were developed from field soils, 

 while the greatest development in others was from greenhouse soil. 



DEVELOPMENT OF ALL FORMS OF PROTOZCV 



For the development of all forms of protozoa hay infusion was more 

 favorable than dried-blood extract. In the former solutions the bacteria 

 seemed to thrive and multiply much more readily than in the latter. 

 Thus, if protozoa feed upon these organisms, favorable conditions for the 

 development of bacteria might have stimulated protozoan life. In com- 

 paring the numbers of all fonns of protozoa present it is seen that the 

 maximum development is always present at an earlier period in the 

 solutions with the largest inoculations. This is in all probability due to 

 the presence of many more cysts in solutions to which larger amounts of 

 soil were added. 



In considering the development of protozoa on the gram-inoculation 

 basis more than one hundred times as many organisms excysted from 

 the smaller than the larger inoculations of soil. This fact mav be due 



