SOIL PROTOZOA IX SOUTH AFKICA. .371 



(5) Among the soils examined, up to the present, fertile soils 

 appear to contain larger numbers of individual Protozoa than 

 infertile soils. This general statement applies to soils from Glen, 

 in the Free State, where there are infertile patches, and to soils 

 from George, where suitability or otherwise for growing pine trees 

 is concerned. 



As regards Glen soils, differences in the species of Amoebae 

 found in the various samples may be noted, while in the case of 

 George soils differences in the Ciliata are of interest. 



Cultivated soils, in general, if not yielding more species of 

 Protozoa than uncultivated soils, yet yielded more Protozoan 

 individuals in cultures. 



(6) The sequence of the appearance of Protozoa in cultures of 

 ■soil from different depths has been tabulated (see pp. 365-6). The 

 ■Flagellata appear to develop relatively early in cultures from any 

 depth of soil, Euglena viridis and E. oxyuris being exceptions and 

 appearing relatively late. E. oxyuris is more longlived in cultures 

 ihan E. viridis. Some Ciliata appear much earlier in cultures 

 than others. Animba proteus sometimes appeared earlier in 

 cultures than other species of amoebae. 



(7) The succession of dominant Protozoa has been studied in 

 cultures of some soils. Secondary or subdominants also occur. 

 These are discussed on p. 367. 



.. (8) Certain Protozoa have appeared sporadically in cultures, 

 and notes are given of the times ol their appearances (see p. 367). 

 (9) Seasonal variation in the protozoal fauna of certain soils 

 is indicated. 



Acknowledgments. 



We wish to thank many friends for aid in collecting samj^les 

 of soil for examination, particularly Messrs. A. Stead and V. 

 Becklcy, of the Grootfontein School of Agriculture, Messrs. Parish 

 and du Plessis, of the Glen School of Agriculture, Professor G. 

 Potts, of Bloemfontein, Mr. T. Hall, of the Potchefstroom School 

 of Agriculture, and Mr. Mally, of the Division of Entomology, 

 who kindly sent us the samples of the Liesbeek soil. We have 

 pleasure in thanking Dr. Annie Porter for general help. We also 

 wish to thank the Research Grant Board for a grant towards the 

 , expenses incurred in these investigations. 



