SECTIONAL TRANSACTIONS.— D. 335 



Special study of soil collected monthly in Milner Park, Johannesburg, has shown 

 that the number of species rose at the onset of spring but decreased with great heat 

 or great cold. Few species of Rhizopoda and Mastigophora occurred during the cold 

 weather, but Ciliata suffered less reduction in numbers. Rhizopoda were most 

 numerous in samples collected in the summer months, and Mastigophora in September 

 (spring) and December (summer) samples. 



Observations on the Protozoa of waterlogged soil collected weekly for a year 

 from the banks of Sans Souci dam, Johannesburg, show that the protozoal fauna 

 varies in numbers with alteration of conditions, decrease in numbers occurring after 

 sudden cold, great heat or great cold, increase in salinity and conditions causing 

 stagnation of soil moisture. Increase in numbers coincided with access of clean, cold 

 water. Mastigophora were dominant, their optimum activity occurring at the onset 

 of spring. Relatively few species of Protozoa occurred in waterlogged soils. 



Soils under irrigation for tobacco and sugar have been found to contain more 

 species of Protozoa than the drier soils under cotton. Of soil samples from various 

 sugar and banana lands, those with most moisture yielded the largest number of 

 species of Protozoa in each case. The food supplies available for the Protozoa vary 

 under these different conditions. The protozoal fauna of a number of soils from the 

 Forest Experiment Station, Knysna, varied in high forests facing north and south ; 

 with presence or absence of tree ferns; and vrith eastern and southern aspects. Varia 

 tions in illumination and moisture also caused considerable differences in protozoal 

 fauna. 



Storage of soil for three years did not entirely destroy its protozoal life, but 

 diminished the numbers of Protozoa and altered the succession of dominant types. 

 Veld-burning was destructive to cysts. 



No general relationship appears to exist between the chemical reaction (fiH) of 

 the soil and the kinds and numbers of Protozoa found therein. 



Species of Rhizopoda and Ciliata from South African soils often appear to be 

 smaller races than those occurring as free-living organisms in water. 



Prof. H. B. Fantham. — Some Parasitic Protozoa found in South Africa. 



The present communication summarises some recent findings of parasitic Protozoa 

 in South Africa, previous records having been published in the South African Journal 

 of Science, vols, xv-xxv (1918-1928). 



An interesting Herpetomonas has been found in the rectum and cloaca of two 

 Cape cobras, Naia Jlava, out of nine examined. Morphologically it is quite distinct 

 from Herpetomonas homalosomatos described by me from the steel snake, Homalosoma 

 lutrix, in 1927. The bodies of the Herpetomonas of Naia are elongate oval, with 

 both flagellar and aflagellar ends rounded. The single flagellum is longer than the 

 body. Non-fiagellate forms are rounded. Active multiplication by longitudinal 

 binary fission occurred. The herpetomonad may have been derived from insects 

 ingested by the snakes, the flagellates having adapted themselves to life in the 

 ophidian gut. 



Herpetomonas ficuum has been observed in Johannesburg in the latex of single 

 leaves of Ficus edulis from two different sources. Leaves from twenty-eight other 

 edible fig trees from different localities were negative. No marked pathological 

 effects, other than very watery latex, were observed. Both flagellate and non- 

 flagellate forms of H. ficuum were seen, the latter being much more numerous in the 

 present (summer) specimens. Infections of the latex of Araujia sericifera by Herpe- 

 tomonas elmassiani and of Euphorbia striata by H. davidi have been recently seen 

 again in single plants. 



Species of Trichomastix have been observed in the rectum and cloaca of Bitis 

 arietans (puff adder), Sepedon hoemachates (ringhals), Pseudaspis cana (mole snake), 

 Leptodira hotambceia (herald or red-lipped snake), Trimerorhinus tritceniatus (lineated 

 schaapsteker), Psammophis sibilans (hissing sand snake), Boodon lineatus (brown 

 house snake), and Dasypeltis scabra (egg eater). Perhaps these flagellates are varieties 

 of Eutrichomaslix serpentis. Varanus albigularis (mountain leguaan) also harbours a 

 Trichomastix. A species of Trichomonas has been found in the cloaca and rectum 

 of the Cape cobra, mole snake, herald snake and boomslang (Disx>holidus typus). 

 Small numbers of Giardia have been seen in the rectum of a night adder and Bodo spp. 

 in the Cape cobra, mole snake, egg eater, night adder and brown house snake. 

 Tricercomonas has been found in the hind gut of several snakes. Multiple infections 

 were fairly common. 



