526 Journal of Agricultural Research voi. iv. no. e 



Large ciliates.— Very few large ciliates developed in any of the 

 inoculated solutions. These organisms appeared on the first day in 

 some moist soil inoculations of dried-blood extract. In blood extract 

 to which dry soil had been added and soil extract inoculated with moist 

 soil large ciliates appeared on the second day in some solutions and 

 on the third day in soil extract containing the largest amounts of dry 

 soil. In all inoculations of dried-blood extract the greatest numbers 

 appeared from the third to the eighth day; then the numbers decreased, 

 so that there were very few in any of the solutions after the ninth day. 

 In soil extract the organisms appeared much sooner in solutions with 

 the larger than in the solutions with the smaller soil inoculations. As 

 noted in Table VII, in solution 36, with 100 gm. of moist soil, the organ- 

 isms developed on the second day, while in solution 30, when i gm. was 

 used, the organisms did not appear until the nineteenth day. As many 

 large ciliates developed in the dried blood as in soil extract. Again 

 there was no definite relation between the numbers of organisms 

 developed and the quantities of soil used for inoculation. 



Flagellates. — As noted in Table VII, in all inoculations of dried- 

 blood extract, the maximum number of flagellates were present at an 

 earlier period than in inoculations of soil extract. The maximum 

 development in dried blood was from the second to the fourth day, 

 depending on the quantity and kind of soil used. The largest number 

 of organisms appeared sooner in solutions inoculated with the largest 

 amounts of soil than where small quantities were used. With loo-gm. 

 inoculations the maximum development of flagellates in solutions of 

 soil extract with both moist and dry soils was on the seventh day, while 

 with I gm. of moist soil the greatest numbers of organisms appeared 

 on the eleventh day, and on the fifteenth day with the same amount 

 of dry soil. As soon as the maximum numbers were reached, there 

 was a gradual decrease until but few organisms remained in the solutions. 

 In culture solutions inoculated with moist and dry soils, the largest 

 development of flagellates was reached in the soil extract with the 

 smallest quantities of soil, while with the largest amounts of soil the greatest 

 development was in dried blood. In soil extract, with one exception, 

 a larger number of flagellates were developed from the dry than from 

 moist soil; this, however, was not the case with inoculations in blood. 

 In nearly all inoculations with dry soil, the greatest numbers were 

 developed in soil extract. In all cases there were nearly 200 times as 

 many organisms developed per gram, from the i-gm. than from the 

 loo-gm. inoculations. In inoculated solutions of blood extract, the 

 maximum number of all organisms appeared between the third and 

 fourth day, while in the soil extract the largest number were present 

 from the second to the fifteenth day, depending upon the kind and 

 amount of soil inoculated. 



