376 SOIL PROTOZOA IN SOUTH AFRICA. 



gradually to decrease and disappear as motile forms, often to re- 

 appear later. Periodicity is thereby indicated. 



The determination of some of the Protozoa has been difficult, 

 especially with the somewhat restricted literature at our disposal 

 in South Africa. 



The Protozoa Found in Certain South African Soils. 



The results of our observations of the Protozoa found in water 

 cultures of different South African soils may now be given. Soil 

 samples from the Western and Eastern Cape Province, the Trans- 

 vaal and Natal, have provided the bulk of the material hitherto. 

 It will be convenient to deal with the soils under two groups : (a) 

 Ordinary (non-waterlogged) soils under degrees of cultivation 

 ranging from virgin soil to heavily cultivated sugar and vine 

 land; and (h) soils that were waterlogged at the time of examina- 

 tion. 



(A) Results of Examination of Various Ordinary 

 (Non- waterlogged) Soils. 



The soils here considered may be grouped as Cape Province, 

 Transvaal and Natal soils. 



I. Cape Province Soils. 



Western Province soils were collected at St. James, Somerset 

 Strand, Stellenbosch, Heathfield, High Constantia, Simonstown, 

 Bellville and Eosebank Experimental Station, near Capetown; 

 while soil from Kimberley was examined as representing Griqua- 

 land. With regard to Eastern Province soils, specimens from Port 

 Elizabeth, Graharmtown and Grootfontein School of Agriculture 

 have been studied. 



St. James. The soil was collected from the foot of the moun- 

 tain on 23rd January, 1921, during fine weather. The sample was 

 taken from a depth of about six inches. It was a dark-greyish soil 

 containing some sea-sand, and gave a feebly alkaline reaction to 

 litmus compression tests. On culture the following Protozoa were 

 obtained : — 



Rhizopoda. — A moeha proteus, A . Umax, A . radiosa, 

 A. verrucosa, A. guttula, Difflugia piriformis, T) . 

 globulosa. 

 Mastigophora. — Mastigamoeoa sp., Oikomonas (Monas) 



termo, Pleuromonas jaculans. 

 Heliozoa. — A ctinophrys sol. 



Infusoria. — Holophrya ovum, Pleuronema chrysalis, 

 Cyclidium glaucoma, Oxytricha pellionella, Vorticella 

 campanula, Lacrymaria olor, Colpoda cuciillus, I'ara- 

 moecium aurelia. 



Somerset Strand. — The soil was sandy and was collected on 

 8th December, 1920, during hot weather, from a flower garden at 

 a depth of six inches. Its reaction to litmus was feebly alkaline. 

 In water culture it yielded: — 



