REPORT

OF THE

EIGHTEENTH ANNUAL MEETING

OF THE

SOUTH AFRICAN ASSOCIATION

FOR THE ADVANCEMENT OF SCIENCE,

BEING VOLUME XVII OF THE SOUTH AFRICAN JOURNAL OF SCIENCE.

BULAWAYO
1920.

JULY 14-17.

JOHANNESBURG:

PUBLISHED BY THE ASSOCIATION.

1921.

PAPERS READ (continued):-

ว

Magnesia Impregnated Soils," by G. N. Blackshaw,

O.B.E., B.Sc., F.I.C.

Note on Kimberlite from the Belgian Congo," by P. Ä.

Wagner, Ing. D., B.Sc.

Constituents of the Flora of Southern Rhodesia," by

F. Eyles

"Additional Host-plants of Loranthaceae

Loranthaceae occurring

around Durban," by Paul A. van der Bijl, M.A., D.Sc.,

F.L.S.

Note on the Crassulaceae found in Rhodesia," by

S. Schonland, M.A., Ph.D.

Ripening of Seed in Gnetum gnenom and Gnetum

africanum," by Mary G. Thoday

"A note on Dasychira extorta and its Lepidopterous

Parasite," by C. P. van der Merwe

Birds and Insects in Bushman Folk-lore," by D. F. Bleek

A Tachinid Parasite of the Honey Bee," by S. H. Skaife,

M.A., M.Sc.

Agricultural Economics-Cost of Production of Maize,"

by R. A. Lehfeldt, D.Sc.

Calibration of Gerber Milk Butyrometers," by C. O.

Williams, B.Sc., A.R.C.S.

Note on Rock-gravings at Metsang, Bechuanaland Pro-

tectorate," by A. J. C. Molyneux, F.G.S.

Some Features of the Religion of the Ba-Venda," by

Rev. H. A. Junod

The Occurrence of Terblanz (Faurea Macnaughtonii,

Phill.) in Natal and Pondoland," by E. P. Phillips,

M.A., D.Sc., F.L.S., and J. J. Kotze, B.A., D.Sc.

"A Method of Veld Estimation," by A. Ó. D. Mogg, B.A.

"Note on
a Diagram showing the amount of Available

Sunshine falling on a Horizontal Surface on any Day

of the Year at a Given Place, and showing also the

Sun's Elevation and its Times of Rising and Setting,"

by J. T. Morrison, M.A., B.Sc., F.R.S.E.

"Note on Older Palaeolithic Implements from the Umguza

and Bembesi Valleys," by A. W. Macgregor, B.A.,

F.G.S.

...

The Effect of Elevation of Temperature and Altitude of

Aerodrome in the Taking-off of Aeroplanes,” by P. G.

Gundry, B.Sc., Ph.D., F.R.Ae.S.

Karroo Rocks in the Mafungabusi, Southern Rhodesia,”

by A. J. C. Molyneux, F.G.S.

On the Volumetric Determination of Phosphoric Oxide,"

by B. de C. Marchand, B.A., D.Sc.

"Some Further Factors influencing the Solubility of

Phosphoric Oxide in Mixed Fertilisers containing

Superphosphates," by Edmund Victor Flack

South African Fern Notes, with List of Ferns and Fern-

Allies found in Southern Rhodesia, and of Additional

Species recorded for other South African Phytographic

Areas," by T. R. Sim, D.Sc., F.L.S.

The Leaves of Hakea pectinata and H. suaveolens," by

Horace A. Wager, A.R.C.Sc.

PAGE

171

179

181

185

186

189

192

194

196

201

205

206

207

221

222

227

230

235

249

259

268

275

284

"Note on the I-Kowe or Natal Kafir Mushroom, Schulzeria

Umkowaan," by Paul A. van der Bijl, M.A., D.Sc.,

F.L.S.

286

"A Paw-Paw Leaf-Spot caused by a Phyllosticta sp.," by

Paul A. van der Bijl, M.A., D.Sc., F.L.S.

"An Exhibit of Stone Implements from Tiger Kloof and

Taungs, Cape Colony," by Rev. Neville Jones, F.E.S.

Some Factors in the Natural Control of the Wattle

Bagworm," by S. H. Skaife, M.A., M.Sc.

288

290

291

-66

Map of South Africa, showing the chief Native Languages

and Dialects," by Rev. G. Beyer

"Notes relating to Aboriginal Tribes of the Eastern

Province," by John Hewitt, B.A.

"The Economic Value of a Study of the Nematodes, with

Remarks on the Life History of Heterodera in South

Africa," by J. Sandground, M.Sc.

"Hottentot Place-Names, by Rev. Charles Pettman

"Snake-Venom and its Effects, especially on other Snakes,'

by F. W. FitzSimons, F.Z.S., F.R.M.S.

INDEX

PAGE

302

304

322

334

353

355

XVIII.-Kameeldoorn Veld of Southern Damaraland

XIX.-Cape Veld or South-Western Veld

34

34

XX.-Karroo

34

XXVI.-The Namib

XXVII.-The Namib

XXI.-Karoo

XXII.-Upper Karroo

XXIII.-Kokerboom Veld of Namaqualand and Bushmanland

XXIV.-Kokerboom Veld of Namaqualand and Bushmanland

XXV.-Kokerboom Veld of Namaqualand and Bushmanland

XXVIII-The Namib

XXIX. Page from "Harper's School Geography," published

in U.S.A. in 1876 ..

XXX.-Stone Implements from Umguza and Bembesi Valleys

XXXI." Strandlooper " Skulls from Port Alfred ...

XXXII.-" Strandlooper Skull and Mandible from Port

34

34

34

34

34

34

34

34

74

234

320

Alfred

320

Erratum.-Owing to an error in the typing of the author's MS., the
figure 100 on line 14 of page 175 should read 1000.

E. H. Adlington, Ltd., Printers, Johannesburg-10436

DEC 974093

THE

SOUTH AFRICAN JOURNAL OF SCIENCE:

COMPRISING THE REPORT OF THE

H. E. WOOD, M.Sc.. F.R.A.S., Union Observatory, Johannesburg.
C. F. JURITZ, M. A., D.Sc., F.I.C., Agricultural Chemical Research Laboratory, Capetown.
HON. GENERAL TREASURER.

J. A. FOOTE, F.G.S., F.E.I.S., Commercial High School, Johannesburg.
HON. LIBRARIAN.

ANNIE PORTER, D.Sc., South African Institute for Medical Research, Johannesburg.

ASSISTANT GENERAL SECRETARY.

H. A. G. JEFFREYS, O.B.E., Box 6894, Johannesburg. Telegraphic Address: "Science."

HON. EDITOR OF JOURNAL.

Prof. H. B. FANTHAM, M.A., D.Sc., University College, Johannesburg.