SOIL I'llOTOZOA IX SOUTH AFIIICA. 



363 



Table IV. 

 (2) Soils at 9 Inches Deep 



The comparison of the fauna of the three soils again shows 

 the presence of Protozoa common to each. These are Eughjpha 

 sp., Oikomonas termo, PcrcDtciiia tricho pliorum, Ple^iromotias 

 jacularis and Cyclidium glaucoma. It is of interest to note that 

 the species of Protozoa common to these soils at six inches deep 

 are different from those common to each kind of soil at nine 

 inches deep, Oikomonas termo excepted. 



Influence of Culture Area Exposed on the Number of Protozoa 



Observed. 



Cultures of equal quantities of soil and water were made in 

 vessels of different diameters, in an endeavour to estimate what 

 influence, if any, the surface area of soil exposed to the direct 

 action of the water had on the rate of development of trophic 

 Protozoa. 



Thus, three cultures were made of soil from a Stellenbosc-h 

 vine,yard — soil known to be rich in Protozoa; different sized vessels 

 were employed, and the results were as follow: — 



(1) A culture of 5 grams of soil in 10 c.c. of boiled sterile 

 water was made in a test tube of 17-5 mm. diameter. On 

 examination after six days of culture, one-half c.c. of the fluid 

 yielded the following trophic Protozoa: — 4 Masiiqamoeha sp., 2 

 Eughipha sp., 18 Pleuromonas jacvlans, 16 Cyclidium glaucoma. 



(2) A similar culture made on the same date in a small Petri 

 dish of 32 mm. diameter, was examined on the same day as 

 culture (1). One-half c.c. of the fluid yielded :^1 Diffltigia 

 ])yriformis\ 8 Mastigamoeha sp., 5 Euglypha sp., 52 Pleuromonas 

 jariilnns, 20 Cyclidium glaucoma. 



