Full text of "South African journal of science"

liilH^'KuiMUHiiiiiiiii'^

REPORT

OP THE

Eighteenth Annual Meeting

OF THE

SOUTH AFRICAN ASSOCIATION

FOR THE ADVANCEMENT OF SCIENCE,
Being Volume XVll of the South African Journal of Science.

BU LAW AYO

1920.

JULY 1 4—1 7.

JOHANNESBURG :

PUBLISHED BY THE ASSOCIATIOX

19 2 1.

") o

CONTENTS.

Constitution of the Association ...
Tables: Past Annual Meetings: —

Places and Dates, Presidents, Vice-Presidents and Local
Secretaries

Sectional Presidents and Secretaries

Evening Discourses
BULAWAYO MEETING, 1920: —

Meetings

Officers of Local and Sectional Committees

Proceedings of Eighteenth Annual General Meeting

Report of Council. 1919-20

Hon. Treasurer's Report and Accounts ...

Thirteenth Award of the South Africa Medal and Grant ...

Association Library

Officers and Council. 1920-21

Pkesident's Address : '' The Veld, its Resources and Dangers."
by I. B. Pole Evans, M.A., D.Sc, F.L.S.

Addresses by Presidents of Sections :

Section A: "Recent Progress in Astronomv." bv H. E.

Wood, M.Sc, F.R.A.S., F.R.Met.S. ... " ...'
Section B: " Geologv in Relation to Mining," by E. P.

Mennell, F.G.S*., M.I.M.M. ...
Section C : " Causes leading toward Progressive Evolution of

the Flora of South Africa," by T. R. Sim, D.Sc, F.L.S.
Section D: "Some Zoological Factors in the Economic

Development of South Africa," by C. W. Mallv, M.Sc,

F.E.S.
Section E: "The Magic Conception of Nature amongst

Bantus," by Rev. Henri A. Junod
Section F : " Labour Conditions in

R. A. Lehfeldt, B.A., D.Sc

Public Lecture : " The Nitrogen Problem,"
M.A.

List of Papers Rkad at the Sectional Meetings

]*AP£RS Read : —

"The Geological Section between Bulawavo and the
Victoria Falls," by H. B. Maufe, B.A. " ...
."Crime and Feeble-mindedness," bv G. T. Morice, K.C..
B.A. ... ... ... ' ...

" Ericoid Leaves," by D. Thoday, M.A (Cantab.)
" The Distribution of Accessorv Food Factors (Vitamines)
in Plants," by E. Marion Delf, D.Sc, F.L.S. ...

■ The Life-history of the African Sheep and Cattle Fluke,
Fasciola r/ifjaiitica,'' by Annie Porter, D.Sc, F.L.S..

F.R.s. (s.A.) ... ... ... ... ..:

" Some Parasitic Protozoa found in South Africa. — III.,"

by H. B. Fantham, M.A. (Cantab.), D.Sc. (Lond.). ...
" The Future of the Native Races of Southern Rhodesia,"

by N. H. Wilson ...
" A Short Note on Einstein's Planetary Equation," by

AV. N. Roseveare, M.A.
" Rainfall and Barom.etric Variation m Bulawayo," by

Father E. Goetz, S.J.. M.A.. F.R.A.S.
" Bat Guano Deposits of Rhodesia." bv Edmund Victor

Flack

South Africa," by
bv J. A. Wilkinson.

XV J

xvii

xxiii
XX vi

XXX

xxxiii
xxxviii

3.5
43
51

95
110

113

116

120

121

126
131
136
151

155
158

CONTENTS. ^^^

Papers Read {continued) : —

PAGE

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

O.B.E., B.Sc, F.I.C. ... ... 171

'• Note on Kimberlite from the Belgian Congo/"' by P. A.

Wagner, Ing. D., B.Sc. ... ... ... ... 179

" Constituents of the Flora of Southern Rhodesia," by

F. Eyles ... ... ... ... ... ... 181

" Additional Host-plauts of Loranthaceae occurring
around Durban," bv Paul A. van der Bijl, M.A., D.Sc,
F.L.S. ... "... ... ... ... ... 185

•■ Note on the Crassulaceac found in Rhodesia," by

S. Schonland, M.A., Ph.D. ... ... ... ... 186

" Ripening of Seed in (Inetum gncnom and Gnetum

africaniim/' by Mary G. Thoday ... ... ... 189

•■ A note on Dasychira extorta and its Lepidopterous

Parasite," by C. P. van der Merwe ... ... ... 192

" Birds and Insects in Bushman Folk-lore," by D. F. Bleek 194

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

M.A., M.Sc. ... ... ... ... ... 196

■• Agricultural Economics — Cost of Production of Maize,"

by R. A. Lehfeldt, D.Sc. ... ... ... ... 201

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

Williams, B.Sc, A.R.C.S. ... " ... ... ... 205

" Note on Rock-gravings at Metsang, Bechuanaland Pro-
tectorate," by A. J. C. Molyneux, F.G.S. ... ... 200

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

Rev. H. A. Junod ^ ... ... ... ... 207

■•The Occurrence of ' Terlilanz ' (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. ... 221

■• A Method of Veld Estimation," by A. O. D. Mogg, B.A. 222

" 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. ... ... 227

" Note on Older Palaeolithic Implements from the Umguza
and Bembesi Vallevs," bv A. W. Macgregor, B.A.,
F.G.S. ... .:. ■ ... ... ... . . 230

" 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. ... ... ... 235

'• Karroo Rocks in the Mafungabusi, Southern Rhodesia,"

by A. J. C. Molyneux, F.G.S. ... ... ... 249

" On the Volumetric Determination of Phosphoric Oxide,"

by B. de C. Marchand, B.A., D.Sc ... ... ... 259

" Some Further Factors influencing the Solubility of
Phosphoric Oxide in Mixed Fertilisers containing
Superphosphates," by Edmund Victor Flack ... 268

■■ 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. ... ... 275

" The Leaves of Ilakea pectinata and H. stiaveolens," by

Horace A. Wager, A.R.C.Sc ... ... ... 284

" Note on the I-Kowe or Natal Kafir Mirshroom, Schiilzcria
Umkoicaan,'' by Paul A. van der Biil, M.A., D.Sc,
F.L.S. ... ■ 286

"A Paw-Paw Leaf-Soot caused by a Phyllnsticta sp.," by

Paul A. van der Bijl, M.A., D.Sc, F.L.S. ... ... 288

" An Exhibit of Stone Implements from Tiger Kloof and

Taungs, Cape Colony," by Rev. Neville Jones, F.E.S. 290

" .Some Factors in the Natural Control of the Wattle

Bagworm," by S. H. Skaife, M.A., M.Sc. ... ... 291

»-»<-* « wv ►**

CONTENTS .

Papeus Read (continuecl) : — •

Index

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.

302
304

322

334

353
355

LIST OF PLATES.

Plate
No.
I.— Coast Veld
11.— Low Veld
111.— Low Veld
IV. — Waterberg Sandveld

V. — Eastern Grassveld
VI. — Eastern Grassveld
Vll.— Bushveld
Vlll.— Bushveld^
IX. — Banken Veld

X.— Highveld
XI. — Griqualand West Thornveld
Xll. — Kaap Plateau Bushveld ...
Xlll. — Kaap Plateau Bushveld ...

XIV. — Vaal Kameeldoorn Veld of Asbestos Mountains
XV. — Vaal Kameeldoorn Veld of Asbestos Mountains
XVI.— Kalahari Sand Veld
XVIL— Damaraland Thorn Veld ...
XVIII. — Kameeldoorn Veld of Southern Damaraland
XIX.— Cape Veld or South- Western Veld

XX. — Karroo
XXI. — Karoo
XXil. — Upper Karroo
XXIII. — Kokerboom Veld of Namaqualand and Bushmanland
XXIV. — Kokerboom Veld of Namaqualand and Bushmanland
XXV. — Kokerboom Veld of Namaqualand and Bushmanland
XXVI.— The Namib
XXVIL— The Namib
XXVIIl.— 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
Alfred

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320

320

Eirainm. — 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

uj;library):3-!

THE

SOUTH AFRICAN JOURNAL
OF SCIENCE,

COMPRISING THE REPORT OF THE

South African Association for the
Advancement of Science.

(1920, BULAWAYO.)
VOL. XVII. NOVEMBER, 1920. No. 1.

CONSTITUTION

OF TH1-:

South African Association for the
Advancement of Science

[As atiip/ided at the Ui///itfent/t Annual Mcefinj/ at Bulawaijo, 1920],

I.— OBJECTS.

The objects of the Association are : — To give a stronger impulse and a
more systematic direction to scientific enquiry : to promote the intercourse
of societies and individuals interested in Science in different parts of South
Africa ; to obtain a more general attention to the objects of pure and applied
Science, and the removal of any disadvantages of a public kind which may
impede its progress.

II.— MEMBERSHIP.

(a) All persons interested in the objects of the Association are eligible
for Membership.

(6) Institutions, Societies, Government Departments and Public Bodies
are eligible as " Instituti<3nal Aleinbers.*'

(c) The Association shall consist of (a) Life Members, (b) Ordinary
Members (both of whom shall be included under the term " Members "[,
(c) Institutional Members, and (d) Temporary [Members, elected for a session,
hereinafter called "Associates."

(d) Members, Institutional Members, and Associates shall be elected
directly by the Council, but Associates may also be elected by Local
Committees. Members may also be elected by a majority of the Members of
Council resident in that centre at which the next ensuing session is to be
held.

(e) The Council shall have the power, by a two-thirds vote, to remove
the name of a member of any class whose Membership is no longer desirable
in the interests of the Association.

III.— PRIVILEGES OF MEMBERS AND ASSOCIATES.

(n) Life Members shall be eligible for all offices of the Association, and
shall receive gratuitously all ordinary publications issued by the Association.

11 CONSTITUTIOX.

(6) Ordinary Members shall be eligible for all offices of the Association,
and shall receive yratmtoudy all ordinary publications issued by the
Association during the year of their admission, and during the years in
which they continue to pay, wifhoiit intti r mis-no n, their Annual Subscription.

(c) Institutional Members shall receive grut.iiitoiisly all ordinary
publications of the Association on the same conditions as ordinary members ;
and each Institutional Member shall be entitled to send one representative
to the Annual Session of the Association.

((■/) Associates are eligible to serve on the Reception Committee, but are
not eligible to hold any other office, and they are not entitled to receive
gratuitously the publications of (he Association.

(e) Members and Institutional Members may purchase from the
Association (for the purpose of completing their sets) any of the Annual
Reports of the Association, at a price to be fixed upon by the Council.

IV. —SUBSCRIPTIONS.

(a) Every Life ]\Ieniber .shall pay, on admission as such, the sum of
Ten Pounds.

(6) Ordinary and Institutional Members shall pay, on election, an
Annual Subscription of One Pound. Subsequent Annual Subscriptions shall
be payable on the first day of July in each year.

(c) An Ordinary Member may at any time become a Life Member by
one payment of Ten Pounds in lieu of future Annual Subscriptions. An
Ordinary Member may, after ten years, provided that his subscriptions have
been paid regularly without intermission, become a Life Member by one
payment of Five Pounds in lieu of future Annual Subscriptions.

{(1) The Subscription for Associates for a Session shall be Ten Shillings.

v.— MEETINGS.

The Association shall meet in Session Annually. The place of meeting
shall be appointed by the Council as far in advance as possible, and the
arrangements for it shall be entrusted to the Local Committee, in conjunction
with the Council.

VI.— COUNCIL.

(«) The Management of the affairs of the Association shall be entrusted
to a Council, five to form a quorum.

(b) The Council shall consist of the President, Retiring President, four
Vice-Presidents, two General Secretaries, the General Treasurer, the Editor
of the publications of the Association, and the Librarian, together with
one Member of Council for every twenty Members of the Association.

(c) The President, ' Vice-Presidents, General Secretaries, General
Treasurer, the Editor of the publications of the Association and the
Librarian shall be nominated at a meeting of Council not later than two
months previous to the Annual Session, and shall be elected at the Annual
General Meeting.

((I) Ordinary Members of Council to represent centres having more than
twenty iMembers shall, not later than one month prior to the Annual Session of
the Association, be elected by each such Centre, in the proportion of one
representative for every twenty Members. The Annual General Meeting
shall elect other Ordinary Members of Council, in number so as to give,
together with the Members of Council already elected by the Centres, in all,
one Member of Council for every twenty Members of the Association.

(f) The Council shall have the power to co-opt Members, not exceeding
five in number, from among the Members of the Association resident in that
Centre at which the next ensuing Session is to be held.

(/) In the event of a vacancy occurring in the Council, or among the
Officers of the Association, in the intervals between the Annual Sessions, or
in the event of the Annual Meeting leaving vacancies, the Council shall have
the power to fill such vacancies.

(<yf) During any Session of the Association the Council shall meet at least
twice, and the Council shall meet at least six times during the year, in
addition to such INIeetings as may be necessary during the Annual vSession
of the Association.

COUNCIL. FINANCE. Ill

{h) The Council shall have the power to pay for the services of Assistant
General Secretaries, for such clerical assistance as it may consider necessary,
and for such assistance as may be needed for the publication of the
Association Report or Journal.

(j) The Council shall have power to frame Bye-laws to facilitate the
practical working of the Association, so long as these Bye-laws are not at
variance with the Constitution.

VII.— LOCAL AND RECEPTION COMMITTEES.

(a) A Local Committee shall be constituted for the Centre at which the
Annual Session is to be lield. and shall consist of the ^lembers of the Council
resident in that Centre, with such other ]\Iembers of the Association as the
said jMembers of Council may elect.

(b) The Local Committee shall form a Reception Committee to assist in
making arrangements for the reception and entertainment of visitors. Such
Reception Committee may include persons not necessarily Members or
Associates of the Association.*

(c) The Local Committee shall be responsible for all expenses in connec-
tion with the Annual Session of tlfe Association.

VIII.— HEADQUARTERS.

The Headquarters of the Association shall be in Johannesburg.

IX.— FINANCE.

{a) Tlie Financial Year shall end on the 31st of May.

(b] All sums received for Life Subscriptions and for Entrance Fees shall
be invested in the names of three Trustees appointed by the Council, and
only the interest arising from such investment shall bei applied to the uses
of the Association, except by resolution of a General Meeting; provided that
any composition fee as a Life ]\Iember paid over to the Trustees of the
Endowment Fund after the 30th day of J\Iay, 1914, may, upon the death of
such Member, be repaid by the Trustees to the General Account of the
Association, if the Council shall so decide.

(c) The Local Committee of the Centre in which the next ensuing Session
is to be held shall have the power to expend money collen.'tied, or otherwise
obtained in that Centre, other than the subscriptions of Members. Such
disbursements shall be audited, and the financial statement and the surplus
funds forwarded to the General Treasurer within one month after the Annual
Session.

{(l) All cheques shall be signed by the General Treasurer and a General
Secretary, or by such other person or persons as may be authorised by the
Council.

(e) Whenever the balance in the hands of the Treasurer shall exceed the
sum requisite for the probable or current expenses of the Association, the
Council shall invest the excess in the names of the Trustees.

if) On the request of the majority of the Members of Council of any
Centre in which two or more Members of Council reside, the Council shall
empower the local Members of Council in that Centre to expend sums not
exceeding in the aggregate 10 per cen.him of the amount of Annual Subscrip-
tions raised in that Centre.

ig) The whole of the accounts of the Association, i.e., the local as well
as the general accounts, shall be audited annually bv an auditor appointed
bv the Council, and the balance-sheet shall be submitted to the Council at
the first meeting thereafter, and be printed in the Annual Report of the
Association.

• The Heception Committee should make arrangements to provide: —

(1) A large hall for the delivery of the Presidential Address and evening lectures.

(2) A large room to be used as a Reception Boom for memher."! and otlwrs, at which
all information regarding the Association c:)n be obtained, and wliich shall have attach.?d
to it two Secretaries' Offices, a Writing Room for memb(rs and other.^. a Smoking Room,
and Ladies' Boom.

Ci) Six rooms, each capable of accommodatins about 30 or JO people, lo be used as
Sectional Meeting Booms, and, if pcFSible, to have rooms attached, or in close pioximity,
for the purpose of holding meetings of Scctumal Committ.es.

(4) Other requirements, such a^ office furniture, hbai-kboards, window blinds to darken
sectional meeting rooms for Lantern lectures, notice boards, etc.

IV COXSTITUTION.

X.— SECTIONS OF THE ASSOCIATION.

The Scientific Work of the Association shall be transacted under such
eeotions as shall be constituted from time to time by the Council, and the
constitution of such Sections shall be published in the Journal.

The Sections shall deal with the following Sciences and such others as-
the Council may add thereto from time to time: — Agriculture; Anthropology
and Ethnology ; Archaeology ; Architecture ; Anatomy ; Astronomy ; Bacteri-
ology ; Botany; Chemistry ; Education; Engineering: Eugenics; Geodesy and
Surveying; Geography. Geology and Mineralogy; Irrigation; IMathematics ;
Mental Science; Meteorology; Philology; Physics; Physiology; Political
Economy ; Sanitary Science ; Sociology ; Statistics ; Zoology.

XI.— RESEARCH COMMITTEES.

(a) Grants may be made by the Association to Committees or to indi-
viduals for the promotion of Scientific research.

(h) Every proposal for special research, or for a grant of money in aid
of special research shall primarily be considered by the Sectional Conimittes
dealing with the science specially concerned, and if such proposal be approved,
shall be referred to the Council.

(c) A Sectional Committee may recommend to Council the appointment
of a Research Committee, composed of Members of the Association, to conduct
research or to administei' a grant in aid of research.

{d) In recommending the appointment of Research Committ.ees, the
Sectional Committee shall specifically name all Members of such Committees ;
and one of them, who has notified his willingness to accept the office, shall
be appointed to act as Secretary. The number of Members appointed to
serve on a Research Committee shall be as small as is consistent with its
efficient working.

(e) All recommendations adopted by Sectional Committees shall be
forwarded without delay to the Council for consideration and decision.

if) Research Committees shall be appointed for one year only, but if the
work of a Research Committee cannot be completed in that year, application
may be made, through a Sectional Committee, at the next Annual Session for
re-appointment, with or without a grant — or a further grant — of money.

{g) Every Research Committee, and every individual, to whom a grant
had been made, shall present to the following Annual i\Ieeting a report of the
progress which has been made, together with a statement of the sums which
haA'e been expended. Any balance shall be returned to the General Treasurer.

{h) In each Research Committee, the Secretary thereof shall be the only
person entitled to call on the Treasurer for such portions of the sums granted
as may from time to time be required.

XII.— SPECIAL COMMITTEES.
The Council shall have power to appoint Special Committees to deal with
such subjects as it may approve, to draft regulations for any such Committees,
and to vote money to assist the Committees in their work.

XIII.— SECTIONAL COMMITTEES.

{a) Tlie Sectional Committees shall consist of a President, two Vicc-
Presideiits. two or more Secretaiies, and such other persons as the Council
may consider necessary, who shall be elected by the Council. Of the
Secretaries, one shall act as Recorder of the Section, and at least one shall
be resident in the Centre where the Annual Session is to be held.

ih) From the time of their election, which shall take place as soon as
possible after the Session of the Association, they .shall form themselves into
an organising Committee for the purpose of obtaining information upon Papers
Ukely to be submitted to the Sections, and for the general furtherance of the
work of the Sectional Committees.

((7) The Committees of the several Sections shall determine the acceptance
of Papers before the beginning of the Session, keeping the General Secretaries
informed from time to time of their work. It is therefore desirable, in order
to give an opportunity to the Committees of doing justice to the several
communications, that each author .should prepare an Abstract of his Paper,

THE vSOUTII AFRICA MEDAL. V

and he should send it, together with the original Paper, to the Secretary of
the Section before which it is to be read, so that it may reach him at least
a fortnight before the Session.

(e) Members may communicate to the Sections the Papers of non-
members.

(/■) The Author of any Paper is at liberty to reserve his right of property
tlierein.

(g) The Sectional Committees shall meet not later than the first day of
the Session in the Rooms of their respective Sections, and prepare the
progi'amme for their Sections and forward the same to the General Secretaries
for publication.

ih) The Council cannot guarantee the insertion of any Report, Paper or
Abstract in the Annual Volume unless it be handed to the Secretary of the
Section before the conclusion of the Session.

(i) The Sectional Committees shall report to the Council what Reports,
Papers or Abstracts it is thought advisable to print, but the final decision
shall rest with the Council.

XIV.— ALTERATION TO RULES.
Any proposed alteration of the Rules —

a. Shall be intimated to the Council three months before the next

Session of the Association.

b. Shall be duly considered by the Council and communicated by

Circular to the j\l embers of the Association for their considera-
tion, and dealt with at the said Session of the Association.
During the interval between two Annual Sessions of the Association, any
alterations proposed to be made in the Rules shall be valid if agreed to by
two-thirds of the Members of Council. Such alteration of Rules shall not
be permanently incorporated in the Constitution until approved by the next
Annual Meeting.

XV.— VOTING.

In voting for Members of Council, or on questions connected with
Alterations to Rules, absent Members may record their vote in writing.

RULES FOR THE AWARD OF MEDALS.
A. The South Africa Medal.
I. — Constitution of Committee.

(a) The Council of the South African Association for the Advancement
of Science shall, annually and within three months after the close of the
Annual Session, elect a Committee to be called " the South Africa Medal
Committee," on which, as far as possible, every Section of the Association and
each Province of South Africa shall have fair representation.

(6) This Committee shall consist of eight Members elected from amnngst
Council Membei's, together with four other Members, .■^elected from amongst
Members of the Association who are not on the Council.

(d) The Chairman of the Committee .shall i)e appointed annually by the
Council from amongst its Members.

(e) Any casual vacancy in the Committee shall be filled by the Council.

II.— Duties.

(a) The duties of the Committee shall be to adminis-ter the Incume of
the Fund and to award the Medal, raised in commemoration of the visit of
the British Association to South Africa in 1905, in accordance with the
resolution of its Council.

(6) This resolu'tion reads as follows:

(1) That, in accordance with the wishes of subscribers, the South
Africa Medal Fund be invested in the names of the Trustees
appointed by the South African Association for the Advancement
of Science.

(2) That the Dies for the Medal be transferred to the A.=;sociation, to
which, in its corporate capacity, the administration of the Fund

Vl CONSTITUTION.

and the award of the Medal shall be, and is hereby, entrusted,
under the conditions specified in the lleport to the Medal
Committee.

(1) That the Fund be devoted to the preparation of a Die for a Medal,
to be struck in Bronze, 2^ inches in diameter; and that the balance
be invested and the annual income held in trust.

(2) That the Medal and income of the Fund be awarded by the South
African Association for the Advancement of Science for achieve-
ment and promise in scientific research in South Africa. ^

(3) That, so far as circumstances admit, the award be made annually.

(cl) The British Association has expressed a desire that the award shall
be made only to those persons whose Scientific work is likely to be usefully
continued by them in the future.

III. — Awards.

{a) Any individual engaged in Scientific research in South Africa shall
be eligible to receive the award.

(b) The Medal and the available balance of on© year's income from the
Fund shall be awarded to one candidate only in each year (save in the case
of joint research) ; to any candidate once only; and to no member of the
Medal Committee.

(c) Nominations for the recipient of the award may be made by any
Member of the South African Association for the Advancement of Science,
and shall be submitted to the Medal Committee not later than six months
after the close of the Annual Session.

(d) Tlie Medal Committee shall recommend the recipient of the award
to the Council, provided the recommendation is carried by the vote of at
least a majority of three-fourtlis of its Members, voting verbally or by letter,
and submitted to the Council at least one month prior to the Annual Session
for confirmation.

(e) The award shall be made by the full Council of the South African
Association for the Advancement of Science after considering the recommenda-
tions of the Medal Commit^tee, provided it is carried by the vote of a majority
of its INlembers. given in writing or verbally.

{f} The Council shall have the light to withhjld the award in any
year, and to devoffe the funds rendered available thereby in a subsequent
award or awards, provided the stipulation contained in the second term of
conveyance of the British Association is adhered to.

{g) No alteration shall be made in these Rules except under the condition
specified in Chapter XIV. of the Association's Constitution, reading: —

Any proposed alteration of the Rules —

a. Shall be intimated to the Council three months before the next

Session of the Association.

b. Shall be duly considered by the Council, and be communicated by

circular to the Members of the Association for their consideration,

and dealt with at the said Session of the Association.

{h) Should a Member of the iNIedal Committee accept nomination for the

Award or be absent from Soutli Africa at any time within four months before

the commencement of the ensuing Annual Session, he will, ipso facto, forfeit

his seat on the Committee.

B. The Goold- Adams Medals.*

(a) The Medals shall be awarded on the joint results of the Matriculation
and University Senior Certificate Examinations of the University of the Cape
of Good Hope.

(6) One Medal shall be awarded to the student who has taken the highest
place in each of the seven Science subjects: (1) Physics, (2) Chemistry,
(3) Elementary Physical Science, (4) Botany, (5) Zoology. (6) Elementary
Natural Science, and (7) Mathematics, as set forth in the L'niversity

• The award of these medals is at present suspended.

BYE-LAWS. Vll

Matriculation Examination and the University Senior Certificate Examination;
and who is not over the prescribed age for Exhi'oitio)is at the Mal'riculation
Examination.

(d) The Medals shall be struck in bronze.

BYE-LAWS.

I. Bye-laws under which the O.F.S. Philosophical Society was incorporated,

from 1st July, 1914, with, the South African Association for the
Advancement of Science, ivith the designation of " The Oraiige Free
State Branch " of the Association.

1. The O.F.S. Philosophical Society to be incorporated with the South
African Association for the Advancement of Science, tins being the only
course of procedure open under the existing Constitution.

2. The title of the Society so incorporated to be "The Orange Free
State Branch of the South African Association for the Ad\ancement of
Science."

3. All members of the South Afiican Association for the Advancement
of Science resident in the Orange Free State will, for purposes of these bye-
laws, be considered members of the Orange Free Sta^te Branch of the
Association.

4. The local Committee of the Branch to consist of the Council members
of the Association for the Orange Free State, together with such additional
members as the Branch may elect to serve on its local Committee.

5. Subscription notices to members of the Brarich to be circulated from the
Head Office of the Association in Johannesburg, and subscriptions to be paid
to the General Treasurer of the Association at Johannesburg, 10 per cent,
thereof being remitted to the Oran£);o Free State Brancli for local expenses.
Subscriptions of £1 per annum to entiiie to membersliio of the Association
as a whole, as well as of the Orange Free State Branch.

6. All members ati present on the books of the Orange Free State
Philosophical Society to be entitled to become member.s of the Association,
to receive its Journal, and to enjoy the full priviliges of membeiship, as soon
as their subscription of £1 for the financial year 1914-15 shall have Joeen paid.

7. Papers read before the Orange Free State Branch may either (Ij be
printed by title, abstract, or in extcnso, in the Journal of the Association for
the current year, after reference to the Presidents of the respective Sectional
Committees, or (2) be read at the next Aimual Session of the Association
(provided that they have not been jneviously jniblished in abstract or in
extenso), and thereafter printed in the Association's Journal, subject to the
ordinary conditions.

II. Bye-laws for the guidance of Sectioned Officers.

1. The afttention of all Sectional Officers is directed to Chapter XIII. of
the A.'jsociation's Constitution, relating to the Sectional Committees and their
functions.

2. The President and Recorxler (or Secretary) of a Section shall have
power during the Annual Session to act on behalf of the Seciion in any
matter of urgency which cannot be brought before the consideration of th?
whole Sectional Committee; and they shall report such action to the next
meeting of the Sectional Committee.

3. The President of the Section, or, in his absence, one of the two Vice-
Presidents, shall preside at all meetings of the Section or of the Sectional
Committee.

4. The President of the Section is expected to prepare a Presidential
Address, which shall be delivered during the Annual Session.

6. Prior to the commencement of the Session, the Recorder of each
Section shall prepare a list of all papers notified to be read during the Session,

Vm CONSTITUTION.

and shall also keep the Assistant Secretary of the Association informed of the
titles and authors of all such papers. The Assisiant Secretary shall, on his
part, keep the Recorder informed of all papers that may be notified to him
direct.

6. When a proposal is made for the reading of a paper at a joint meeting
of Sections, the President, Recorder and Secretary of each Section shall,
ax officio, attend a meeting convened by a General Secretary to consider the
same.

7. During the continuance of the Annual Session, the Local Secretary of
each Section shall be responsible for the punctual transmission to the Assistant
Secretary of the daily programme of his Section for early publication, and of
any other recommendations adopted by the Sectional Committee ; and shall,
at the close of the Session, furnish the Assistant Secretary with a list, showing
which of the papers notified for reading before the Section have been so read,
and which have been taken as read, and giving the dates in either case.
He shall, at the same time, indicate the recommendations of the Sectional
Committee with respect to each paper, i.e., whether it .'should be printer'' in
full, or in abstract, or by title only.

8. Each Sectional Committee shall cause to be prepared a record of the
discussion on each paper read at its meeting ; and such record shall be attached
to the paper and handed in with the same in terms oi Clause 11 of these
instructions.

9. Each Sectional Committee shall, during the continuance of the Annual
Session, meet daily, unless otherwise determined, to compleite the arrange-
ments for the next day.

10. In deciding on any recommendation regarding the printing of or
otherwise of a paper submitted to it, the Sectional Committee shall consider
only the merits of the paper, and not the financial condition of the Association.

11. The Local Secretary of each Section shall, at the close of each day,
collect the papers that have been read and hand them to the Assistant
Secretary, together with a note explaining the cause of absence of any paper
not so handed over.

12. Sectional Officers shall do their utmo.st to ensure punctual commence-
ment and termniation of the Section's daily proceedings; and, in drafting the
programme for the next day, the Committee shall endeavour to allot a
specified time to the reading and discussion of each paper, in order to prevent
other Sections or the Association as a whole being inconvenienced in conse-
quence of delays.

III. Bye-law< for the Affiliation of Scientific and Kindred Societies.

Philosophical and Scientific Societies, and other Associations of a kindred
character may. on application to, and with the approval of tho Council,
affiliate with the South African Association for the Advancement of Science
on the following conditions :

1. That as a Society can only be affiliated on the approval of the Council,
no minimum of membership of such Society need be specified.

2. That each Society shall pay the Association a minimum fee of £5 for
a strength of 50 members or less, and a further £1 for each additional 10 or
portion of 10 members.

3. That such Society shall be entitled to one copy of the South African
Journal of Scienca for each £1 paid to the Association.

4. That such Society may, if it has a strength of 50 members, be repre-
sented on the Council of the Associatdon by its President or such other
member as may be nominated for the purpose.

5. That all members of affiliated Societies may join the Association as
ordinary members, with full privileges, at a reduced annual subscription
of 15s.

6. That affiliated Societies shall be asked to take intO' consideration the
admission of members of the Association into their Societies at a reduced
subscription.

7. That papers contributed to affiliated Societies may, on recommendation
of both their own Council and that of the Association, be printed in the
Association's Journal of Science, after which the authors shall be entitled
to reprints on the usual terms.

TLACES, DATES AND OlFICERS OF PAST MEETINGS

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OFFICERS OF SECTIONS. XI

Presidents and Secretaries of the Sections of the Association.

Date and Place. Presidents. Secretaries.

SECTION A.— ASTRONOMY, CHEMISTRY, MATHEMATICS.
METEOROLOGY AND PHYSICS.

1903. Cape Town ... Prof. P. D. Hahn, M.A., Prof. L. Crawford.

Ph.D.

1904. Johannesburg* J. R. Williams, M.I.M.M., W. Cullen, R. T. A. Innes.

.AI.Amer.I.M.E.

1906. Kimberlev ... J. R. Sutton, M.A. W. Gasson, A. H. J. Bourne.

1907. Natalt .." ... E. N. Neville, F.R.S.. D. P. Reid, G. S. Bishop.

F.R.A.S., F.C.S.

1908. Grahamstown ... A. W. Roberts, D.Sc, 'D. Williams, G. S. Bishop.

F.R.A.S., F.R.S.E.

ASTRONOMY, MATHEMATICS. PHYSICS, METEOROLOGY,

GEODESY, SURVEYING, ENGINEERING, ARCHITE( TURUE

AND GEOGRAPHY.

1909. Bloemfontein ... Prof. W. A. D. Rudge, H. B. Austin, F. Masey.

M.A.

1910. Cape Town: ... Prof. J. C. Beattie, D.Sc, A. H. Reid, F. Flowers.

F.R.S.E.
191L Bulawayo ... Rev. E. Goetz, S.J., M.A., A. H. Reid, Rev. S. S. Dornan.

1912. Port Elizabeth H. J. Holder, M.I.E.E. A. H. Reid.

1913. Lourengo J. H. von Hafe. Prof. J. Orr, J. Vafi Gomes.

Marques

1914. Kimberley ... Prof. A. Ogg, I\I.A,, B.Sc, Prof. A. Brown, A. E. H. Din-

Ph.D. ham-Peren.

1915. Pretoria ... F. E. Kanthact, M.I.C.E., Prof. A. Brown, J. L. Soutter.

M.I.M.E.

1916. Maritzburg ... Prof. J. Orr, B.Sc, Prof. A. Brown, P. Mesham.

M.I.C.E.

1917. Stellenbosch ... Prof. W. N. Roseveare, Prof. A. Brown, L. Simons.

M.A.

1918. Johannesburg... Prof. J. T. Morrison. I\I.A., Prof. A. Brown. Prof. J. P.

B.Sc. F.R.S.E. Dalton.

1919. Kingwilliams- W. Ingham, M.LC.E., Dr. J. Lunt, T. G. Caink,

town. M.I.M.E. J. Powell.

1920. Bulawavo ... H E. Wood, M.Sc, Prof. J Orr, A. C. Jennings.

F.R.A.S.

SECTION B.— ANTHROPOLOGY, ETHNOLOGY, BACTERIOLOGY,
BOTANY, GEOGRAPHY, GEOLOGY, MINERALOGY AND ZOOLOGY.

190o. Cape Town ... R. Marloth, M.A., Ph.D. Prof. A. Dendy.

1904. Johannesburg... G. S. Corstorphine, B.Sc, Dr. W. C. C. Pakes, W. H.
Ph.D., F.G.S. Jollvman.

1906. Kimberlev ... Thos. Quentrall, M.I.M.E., C. E. Addams, H. Simpson.

F.G.S.

CHEMISTRY, METALLURGY, MINERALOGY, ENGINEERING,
MINING AND ARCHITECTlfRE.

1907. Natal C. W. IMethven. .M.LC.E., R. G. Kirkbv, W. Paton.

F.R.S.E, F.R.I B.A.

1908. Grahamstown... Prof. E. H. L. Schwarz, Prof. G. E. Cory, R. W.

A.R.C.S., F.G.S. Newman, J. Muller.

* Metallurgy added in 1904.

t Geography and Geodesy transferreil to Sfction X and Chr-mi&trv and Metallurgy to
Section B, ni 10O7.

t Irrigation added in 1910 and Geography transferred to Section B.

Date and Place.

OFFICERS OF SECTIOXS

Presidents.

Secretaries.

CHEMISTRY. BACTERIOLOGY. GEOLOGY. BOTANY, MINERALOGY,
ZOOLOGY. AGRICULTURE, FORESTRY, SANITARY SCIENCE.

Dr. G. Potts, A. Stead.

1909. Bloemfontein .
CHEMISTRY

C. F. Juritz. M.A.. D.Sc.
F.I.C.

GEOLOGY. METALLURGY, MINERALOGY AND
GEOGRAPHY.

1910. Cape Town ...

1911. Bulawayo

1912. Port Elizabeth

1913. Lourengo

Marques

1914. Kimberley

1915. Pretoria

1916. Maritzburg

1917. Stellenbosch ...

1918. Johannesburg...

1919. Kingwilliams-

town.

1920. Bulawavo

A. W. Rogers, M.A.. J. G. Rose, G. F. Avers.

Sc.D.. F.G.S.
A. J. C. Molvneux. F.G.S., J. G. Rose, G. N. Blackshaw.

F.R.G.S. '
Prof. B. de St. J. van der J. G. Rose, J. E. Devlin.

Riet. :\I.A.. Ph.D.
Prof. R. B. Young, M.A., Prof. G. H. Stanlev, Capt. A.

D.Sc. F.R.S.E., F.G.S. Gratja.

Prof. G. H. Stanlev, J. G. Rose, J. Parry.
A.R.S.M., M.LM.E.,
.AI.I.M.M., F.I.C.
H. Kvnaston, .M.A., F.G.S. Dr H. C. J. Tietz. Prof. D.

F. du Toit I\Ialherbe.
Prof. .J. A Wilkinson, Dr. H. C. J. Tietz. Prof. J. W

M.A.. F.C.S. Bews.

Prof. M. :\I. Rindl, Ing.D. Dr. H. C. J. Tietz. Prof. B. de

St. J. van der Riet.
P. A. Wagner, Ing.D., Dr. H. C. J. Tietz, Dr. J.

B.Sc. Moir.

H. H. Green, D.Sc, F.C.S. Prof. J. A. Wilkinson, T. H.

Harrison, W. G. Chubb.
F. P. ]\[ennell. F.G.S.. J. H. Hutcheon, A. M. Mac-
M.LM.M. Gregor.

SECTION C— AGRICULTURE, ARCHITECTURE, ENGINEERING,
GEODESY, SURVEYING, AND SANITARY SCIENCE.

1903. Cape Town ... Sir Chas. Metcalfe, Bart., A. H. Reid.

M.I.C.E.

1904. Johannesburg* I ieut.-Colonel Sir Percy G. S. Burt Andrews, E. J.

Girouard, K.C.M.G., Laschinger.

D.S.O.

1906. Kimberley ... S. J. Jennings, C.E., D. W Greatbatch, W. New-
M.Amer.I.M.E., M.LM.E. digate.

BACTERIOLOGY, BOTANY, ZOOLOGY, AGRICULTURE AND FORESTRY.
PHYSIOLOGY, HYGIENE.

I;ieut. -Colonel H. Watkins W. A. Squire, A. M. Neilson,

Pitchford, F.R.C.V.S. Dr. J. E. Duerden.

Prof. S. Schonland, M.A., Dr. J. Bruce Bavs, W. Robert-

Ph.D., F.L.S., C.M.Z.S. son, C. W. M'ally, Dr. L. H.

Gough.

Prof. H. H. W. Pearson, W. D. Severn, Dr. J. W. B.

:\I.A., Sc.D., F.L.S. Gunning.

F. Eyles, F.L.S. . INI.L.C. W. T. Saxton, H. G. Mundy.

F. W. FitzSimons, F.Z.S., W. T. Saxton, I L. Drege.

F.R.M.S.
A. L. I\I. Bonn. C.E.

1907. Natal

1908. Grahamstown...

110. Cape Townt ••

1911. Bulawayo

1912. Port Elizabeth

1913. Lourengo

Marques

1914. Kimberley

1915. Pretoria

1916. Maritzburg

1917. Stellenbosch ...

F. Flowers, Lieut. J. B.

Botelho.
C. W. Mallv, W. J. Calder.

Prof. G. Potts. AI.Sc.

Ph.D.
C. P. Lounsburv. B.Sc.

F.E.S.
I. B. Pole-Evans. M.A.

J. Burtt-Davv, F.L.S.. C. W. Mally, C. S. Grobbelaar.
F.R.G.S.

C. W. Mally, A. K. Haagner
C. W. TNlally, Prof. E. Warren.

" Forestry added in 1904.

t Sanitary Science added in 1910.

OFFICERS OF SFXTIOXS. Xlll

Date and Place. Presidents. Secretaries.

BOTANY, BACTERIOLOGY, AGRICULTURE, AND FORESTRY.

1918. Johannesburg... C. E. Legat. B.Sc. Dr. E. P. Phillips. J. Burtt-

Davy.
19m Kingwilliams- Ethel M. Doidge, I\I.A., Dr. E. P. Phillips, E. W.

town D.Sc. F.L.S. Dwyer, Dr. G. Rattray.

1920. Bulawayo ... T. R. Sim, D.Sc, F.L.S. Dr. E." P. Phillips, Prof. H. A.

Wager.

SECTION D.— ZOOLOGY, PHYSIOLOGY. HYGIRNE, AND SANITARY

SCIENCE.

1918. Johannesburg... Prof. E. J. Goddard, B.A.. C. W. Mallv, R. J. Ortlepp

D.Sc.

1919. Kingwilliams- Prof. E. Warren, D.Sc. C. W. Mally, Dr. J. I.

town Br' wnlee, B. H. Dodd.

1920. Bulawayo ... C. W. :Mally, M.Sc, F E.S. Dr. Anr.ie Porter, P. H. Taylor.

SECTION E.- ANTHROPOLOGY. ETHNOLOGY. ECONO:\riCS. SOCIOLOGY,

AND STATISTICS.

19C8. Grahamstown... W. Hammond Tooke. Prof. A. S. Kidd.

ANTHROPOLOGY, ETHNOLOGY, NATIVE EDUCATION, PHILOLOGY,
AND NATIVE SOCIOLOGY.

1917. Stellenbosch ... Rev. N. Roberts. Rev. E. W. H. Musselwhite,

Prof. J. J. Smith.

1918. Johannesburg... Rev. W. A. Norton B.A., Rev. E.^ W. H. Musselwhite,

B.Litt. Rev. G. Evans.

1919. Kingwilliams- Rev. J. R. L. Kingon, Rev. E. W. H. Musselwhite,

town M.A., F.R.S.E., F.L.S. G. R. Spencer, M. Flem-

mer.

1920. Bulawayo ... Rev. H. A. Junod. N. H. Wilson, Rev. N. Jones.

SECTION F.— ARCH.ICOLOGY. EDUCATION. AlENTAL SCIENCE, PHILOLOGY,
POLITICAL ECONOMY, SOCIOLOGY AND STATISTICS.

1903. Cape Town ... Tho.s. Muir, C.M.G.. M.A., Prof. H. E. S. Fremantle.

LL.D., F.R.S., F.R.S.E.

1904. Johannesburg... (Sir Percy Fitzpatrick, Howard Pirn, J. Robinson.

M.L.A.), E. B. Sargant,
M.A. (Acting).

1906. Kimberley ... A. H. Watkins, M.D , E. C. Lardner-Burke, E. W.

M.R.C.S. Mowbray.

ANTHROPOLOGY, ARCHAEOLOGY, ECONOMICS. EDUCATION,
ETHNOLOGY, HISTORY, PSYCHOLOGY. PHILOLOGY,
SOCIOLOGY, AND STATISTICS.

1907. Natal R. D. Clark, M.A. R. A. Gowthorpe, A. S.

Langley, E. A. Belcher.

ARCHEOLOGY, EDUCATION, HISTORY, PSYCHOLOGY, AND PHILOLOGY.

1908. Graham.stown... E. G. Gane, M.A. Prof. W. A. Macfadyen, W.

D. Neilson.

Date aiicl Place.

OFFICERS OF SECTIO]SrS.

Presidents.

Secretaries.

ANTHROPOLOGY, ETHNOLOGY, EDUCATION. HISTORY, MENTAL
SCIENCE, PHILOLOGY, POLITICAL ECONOMY, SOCIOLOGY AND
STATISTICS.

1909. Bloemfontein ... Hugh Gunn, M.A. C. G. Grant, Rev. W. A.

Norton.

1910. Cape Town ... Rev. W. Flint, D.D. G. B. Kipps, W. E. C. Clarke.
1911 Bulawayo ... G. Duthie, M.A., F.R.S.E. G. B. Kipps, W. J. Shepherd.

1912. Port Elizabeth W. A. Way, M.A., G. B. Kipps, E. G. Bryant.

1913. Lourengo J. A. Foote, F.G.J^ H. Pirn, J. Elvas.

JNIarques.

1914. Kimberley ... Prof. W. Ritchie, M.A. Prof. R. D. Nauta, A. H. J.

Bourne.

1915. Pretoria ... J. E. Adamson, 1\I.A. Prof. R. D. Nauta, R. G. L.

Austin.

1916. Maritzburg ... M. S. Evans, C.M.G., Prof. R. D. Nauta, Prof. 0.

F.Z.S. Waterhouse.

EDUCATION, HISTORY, jNIENTAL SCIENCE, POLITICAL ECONOMY,
GENERAL SOCIOLOGY, AND STATISTICS.

1917. Stellenbosch ... Rev. B. P. J. JNfarchand, Prof. R. D. Nauta, Dr. Bertha

B.A. Stoneman

1918. Johannesburg... Prof. T. M. Forsyth, M.A., Prof. R. D. Nauta, J. Mitchell.

D.Phil.

1919. Kingwilliams- Prof. R. Leslie, M.A., Prof. R. D. Nauta, J. Wood,

town F.S.S. F. J. Cherrigh.

1920. Bulawayo ... Prof. R. A. Lehfeldt, B.A., J. Mitchell, B. M. Narbeth.

D.Sc.

Date and Place.

EVENING DISCOURSES.

Lecturer. Subject of Discourse.

1903. Cape Town ... Prof. W. S. Logeman, The Ruins of Persepolis and

B.A., L.H.C. how the Inscriptions were

read.

1904. Johannesburg... H. S. Hele Shaw, LL.D., Road Locomotion — Present and

F.R.S., M.I.C.E. Future.

1906. Kimberley ... Prof. R. A. Lehfeldt, B.A., The Electrical Aspect of

D.Sc. Chemistry.

W. C. C. Pakes, L.R.C.P., The Immunisation against

M.R.C.S., D.P.H., F.I.C. Disease of Micro-organic

Origin.

1907. Maritzburg ... R. T. A. Innes, F.R.A.S., Some Recent Problems in

F.R.S.E. Astronomy.

Durban ... Prof. R. B. Young, M.A., The Heroic Age of South

B.Sc, F.R.S.E.. F.G.S. African Geology.

EVENING DISCOURSES.

Date and Place.
1908. Grahanistown ,

1909. Bloemfoiitein ..

Maseru

1910. Cape Town ..

1911. Bulawayo

1912. Port Elizabeth

1913. Louren50

Marques

1914. Kiniberley

1915. Pretoria

1916. Maritzburg ...
Durban

1917. Stellenbo.sch ...

1918. Johannesburg...

1919. Kingwilliams-

town

East London ...

1920. Bulawayo

Lecturer.
Prof. G. E. Tory, M.A.
A. Theiler, C.M.G.

Subject of Discourse.

The History of the Eastern
Province.

Tropical and Sub-tropical
Diseases of South Africa ;
their Causes and Propaga-
tion.

C. F. Juritz, ^LA.. D.Sc, Celestial Chemistry.
F.LC.

W. Cullen.

Explosives : their Manufacture
-md L^se.

R. T. A. Lines, F.R A.S., Astronomy.
F.R.S.E.

Piuf. H. Lfhle, M.LE.E. The Conquest of the Air.

,J. Brown. I\LD. , C.I\L. Electoral Reform — Proportional

F.R.C.S., L R.C.S.E. Representation.

W. II Logcman, M.A. The Gyroscope.

A. W. Roberts, D.Sc, Imperial Astronomv.
F.R.A.S., F.R.S.E.

Prof. E. J. Goddard, B.A., Antarctica.
D.Sc.

S. Seruya. The History of Portuguese

Conquest and Discovery.

Prof. E. H. L. Schwarz, The Kimberley Mines, their

A.R.C.S., F.G.S. DiscoveiT', and their relation

to other Volcanic Vents in
South Africa.

E. T. Mellor, D.Sc, F.G.S., The Gold-bearing Conglomerates

M.I.M.M. of the Witwatersrand.

C. W. IMallv, :M.Sc., The House Fly under South

F.E.S., F.L.S. African conditions.

C. P. Lounsburv, B.Sc, Scale Insects and their travels.
F.E.S.

R. T. A. Innes, F.R.A.S , A.stronomy.
F.R.S.E.

H. E. Wood, M.Sc,
F R.Met.S.

Some Unsolved Problems of
Astronomy.

Pruf. J. D. F. Gilchrist, Some Marine Animals of South
IM.A., D.Sc. Ph.D., Africa.

F.L.S., C.M.Z.S.

Prof. H. B. Fantham, Evolution and Mankind.
M.A.. DSc, A.R.C.S.,
F.Z.S.

Prof. J. E. Duerden, M.Sc, Ostriches.
Ph.D., A.R.C.S.

Prof. E. J. Goddard, B.A., Tlic Approaching South Afri-
D.Sc can Antarctic Expedition.

Early History of Kaffraria and
East London.

Prof. G. E. Cory, M.A.

Prof. J. A. Wilkinson, The Nitrogen Problem.
M.A., F.C.S.

(luIlibrary)^

XVI

MEETINGS AT BULAWAYO.

On Wednesdai/, Jvlij 14, 1920, at 11 a.m., the Associatiou
was ofiicially welcomed by His Worship the Mayor of Bulawayo
(Councillor Jas. Cowden) and the Borough Council in the
Eveline School. Dr. I. B. Pole Evans (President) and
Prof. J. A. Wilkinson (Vice-President) responded.

At 11.30 a.m., Mr. H. E. Wood, M.Sc, delivered an
address, as President of Section A, on " Eecent Progress in
Astronomy." Mr. C. W. Mally, M.Sc, followed with an
address, as President of Section D, on " Some Zoological Factors
in the Economic Development of South Africa."

At 2 p.m.. Members of the Association proceeded on motor
trips to the Khami Euins or to the Cement Works.

At 8.30 p.m., Dr. I. B. Pole Evans, M.A., E.L.S.,
President, delivered an address on " The Veld: Its Eesources
and Dangers," in the Grand Hotel, Mr. E. W. Miolee
presiding. (See page 1.)

The President subsequently presented the South Africa
Medal to Professor E. Warren, D.Sc. (See page xxx.)

On Thursday, July 15, at 9.30 a.m., Mr. F. P. Mennell
delivered an address, as President of Section B, on " Geology
in Eelation to Mining " in the Public Library. The
Eev. H. A. Junod followed with an address, as President of
Section E, on " The Magic Conception of Nature among
Bantus."

Sectional Meetings took place in the afternoon.

At 8.30 p.m.. Members attended a reception and con-
versazione, held bv His Worship the Mavor, in the Grand
Hotel.

On Friday, July 16, at 9.30 a.m., Dr. T. E. Sim delivered
an address, as President of Section C, on " Causes leading
toward Progressive Evolution of the Flora of South Africa."

At 11 a.m., Members proceeded by motor cars to the
Matopos and World's View.

At 8.15 p.m., Prof. J. A. Wilkinson, M.A., gave a
popular lecture on " The Xitrogen Problem," in the Public
Library, the President of the Association presiding.

On Saturday, July 17, at 9.30 a.m., the Eighteenth Annual
General Meeting was held in the Public Library, for Minutes
of which see page xx.

At 11.30 a.m., Prof. E. A. Lehfeldt, B.A., D.Sc,
delivered an address, as President of Section F, on " Labour
Conditions in South Africa."

Sectional Meetings took place in the early afternoon.

At 4 p.m.. His Honour the Administrator of Southern
Ehodesia, Sir Drummond Chaplin, and Lady Chaplin gave a
Garden Partv to Members at Government House.

On the evening' of Saturday, July IT, the Members
proceeded to the Victoria Falls, and on Tuesday afternoon,
July 20. attended a Garden Party kindly given by His Honour
the Administrator of Northern Ehodesia, Sir Laurence
Wallace, at the Government House, Livingstone.

OFFICERS OF LOCAL AND SECTIONAL
COMMITTEES, BULAWAYO, 1920.

LOCAL CO]iIMITTEE.

Chairman, AY. F. Miolee; Members, G. Arnold, D.Sc,
G. J^. Blackshaw, B.Sc, Rev. H. Brown, C. Dixon, Rev. S. S.
Dornan, B.A., H. B. Douslin, F. Eyles, E. Y. Flack, Eev. E.
Goetz, M.A., A. M. MacGregor, B.A., IL B. Maiife, B.A.,
F. P. Mennell, A. J. C. Molvneiix, G. A. Ping-stone,
Mr. Justice Eussell, B.A., LL.BV, J. W. Sly, Dr. E. H.
Strong, N. H. Wilson, A. R. Welsh; Local Secretary , D. Niven.

EECEPTIOX COMMITTEE.

His Worship the Mayor, Councillor James Cowden
{Chairman), D. Xiven [Secretary), Councillors C. Dixon,
H. R. Barbour, ^\ . J. Bickle, J. H. Bookless, IL B. Ellen-
bogen, C. T. Eriksson, H. C. Fletcher, Dr. S. L. J. Steggall,
F. Fitch {Town Cleric), Dr. G. Arnold, R. Aserman, W. J.
Atterbury, J. H. Ayliug, F. R. Barnes, E. Basch, Col. C. F.
Birney, Lieut. -Col. J. Brady, G. N. Blackshaw, W^. A. Caton,
W. A. Carter, N. H. Chataway, H. A. CToete, Sir Charles
Coghlan M.L.C., J. C. Coghlan, Rev. M. I. Cohen, A. J. Cole,
Major J. C. Jesser Coope, C. E. G. Cumings, W^. Cunningham,
A. J. Davies, C. Davis, E. B. de Beer, H. A. de Beer, Rev.
S. S. Dornan, W. E. Dowsett, Major C. Duly, Dr. Eaton.

F. Eyles, F. Fisher. E. Y. Flack, C. D. Fleming, P. Fletcher,
R. X. Fletcher, M.L.C.. L. R. Forbes, Dr. A. F. Forrester.

G. Fortune, A. Eraser. A. M. Eraser, Rev. E. Goetz, jN". Gritfin,
H. T. Guerrier, F. L. Hadfield, YI.L.C, A. Harrington,
A. G. Hay, Capt. X. G. Hendrie, Capt. Bryce Hendrie,
Sir Melville Heyman, Capt. W\ C. Hoaten, G. R. Holgate,
H. S. Hopkins, Rev. Horn, Advocate Hudson, H. M. Huntley,
J. Hynd, F. Issels, H. M. G. Jackson, A. Jacobs, Rev.
Johanny, Lieut. -Col. D. Judson, G. G. Kempster, Rev. Kendal,
G. H. Laidman, L. Landau, H. T. Longden, H. T. Low,
J. G. Macdonald. O.B.E., D. MacGillivray. A. M. Macgregor,
F. A. Mallett, Dr. MacLaren, H. B. Maufe, T. Meikle, F. P.
Mennell, W\F . Miolee, A. H. Mitchell, A. J. C. Molyneux,
R. M. Kairn, C. H. Read, G. A. Pingstone, L. G. Puzey,
A. C. Ravmer. S. Redrup, Major Robertson, C. Rodney,
Mr. Justice Russell, F. Scott, J. W. Sly, T. Beach Smitii.
Rev. J. Stanlake, G. Stewart, Dr. E. H. Strong, G. Sutherland,
P. IL Taylor, H. B. Thomas, Lieut. -Col. A. Tomlinson,
Dr. A. Y^igne, Lieut. -Col. A. C. L. AYebb, F. L. Walkden,
A. R. Welsh, Dr. S. Wliite, N". H. W^ilson, C. F. de B.
Winslow, Rev. J. P. Y^oung.

SECTIONAL COMMITTEES.

Section A.— ASTRONOMY, MATHEMATICS, PHYSICS,
METEOROLOGY, GEODESY, SURVEYING, ENGIN-
EERING, ARCHITECTURE AND IRRIGATION.

President, H. E. Wood, M.Sc, F.R.Met.S., F.R.A.S.;
Vice-Presidents, Rev. E. Goetz, M.x\., E.R.A.S., J. Luiit,
D.Sc; Members, Sir J. C. Beattie, D.Sc, F.R.S.E., Prof.
A. Brown, M.A., B.Sc, Percy Cazalet, M.I.M.M., Prof. L.
Crawford, M.A., D.Sc, E.R.S":E., Prof. A. E. du Toit, M.A.,
Prof. P. G. Gimdrv, B.Sc, Ph.D., A.R.C.S., C. J. Gyde,
A.M.I.C.E., W. Ingham, M.I.C.E., M.I.M.E., R. T. A.
Innes, E.R.A.S., F.R.S.E., D. Judson, M.I.E.E., F. E.
Kanthack, C.M.G., M.I.C.E., M.I.M.E., S. de J. Lenfesty,
M.A., W. F. Miolee, Prof. J. T. Morrison, M.A., B.Sc,
F.R.S.E., N. Mudd, M.A., Prof. A. Oo-g., M.A., B.Sc, Ph.D.,
A. H. Reid, F.R.I.B.A., A. W. Roberts, D.Sc, F.R.A.S.,
F.R.S.E.; Recorder, Prof. J. Orr, O.B.E., B.Sc, M.I.C.E. ;
Ron. Secretary, A. C. Jennings, A. M.I.C.E.

Section B.— CHEMISTRY, GEOLOGY, METALLURGY,
MINERALOGY AND GEOGRAPHY.

President, F. P. Mennell, F.G.S., M.I.M.M. ; Yice-Fresi-
dents, G. N. Bkckshaw, O.B.E., B.Sc, F.C.S., Prof. R. B.
Denison, ]).Sc ; Members, Prof. E. Anderson, 15. Sc, Ph.D.,
Clement Dixon, M.I.M.M., Jas, Grav, F.I.C., H. H. Green,
D.Sc, F.C.S., C. F. Jiiritz, M.A., D.Sc, F.I.C., E. T. MeUor,
D.Sc, F.G.S., J. McCrae, Ph.D., F.I.C., .1. Moir, M.A.,
D.Sc, F.I.C., B. de C. Marchand, B.A., D.Sc, Prof. D. F.
dii T. Malherbe, M.A., Ph.D., A. J. C. Moivneux, F.G.S.,
G. A. Pingstone, F.C.S., Prof. M. M. Rindl,' Ing.D., Prof.
E. H. L. Schwarz, A.R.C.S., F.G.S., Prof. H. Tietz, M.A.,
Ph.D., Prof. B. de S. J. van der Riet, M.A., Ph.D., P. A.
Wagner, Ing.D., B.Sc, Prof. J. A. Wilkinson, M.A., F.C.S.,
Prof. A. Young, M.A., D.Sc; Recorder, J. H. Hutcheon,
M.A., F.R.S.G.S.; Hon. Secretary, A. M. MacgTegor, B.A.,
F.G.S.

Section C— BOTANY, BACTERIOLOGY, AGRICULTURE
AND FORESTRY.

President, T. R. Sim, D.Sc; Vice-Presidents. E. A.
Nobbs, Ph.D., Prof. D. Thodav, M.A. ; Members, Prof. A. M.
Bosman, B.Sc, Prof. R. II. Compton, M.A., MissE. M. Doidg-e,
M.A., D.vSc, F.L.S., Miss A. V. Diithie, M.A., F. Eyles,
F.L.S., E. Holmes-Smith, B.Sc, Miss M. Heatlev, M.A.,
R. A. Fletcher, Prof. J. M. Hector, B.Sc, C. E. Legat, B.Sc,
Prof. C. E. Moss. M.A., D.Sc, F.L.S., G. H. Mundv, F.L.S.,
Prof. G. Potts, M.Sc, Ph.D., Prof. A. I. Perold, B.A., Ph.D.,
Yen. Archdeacon F. A. Rog-ers, M.A.. Mrs. Russell, B.A.,
Prof. S. Schonland, M.A., Ph.D., F.L.S. ; Recorder, E. P.
Phillips, M.A., D.Sc; Hon. Secretary, Prof. H. A. Wager,
A.R.C.S.

SECTIO-NAL COMMITTEES. XIX

Section D.— ZOOLOGY, PHYSIOLOGY, HYGIENE AND
SANITARY SCIENCE.

Fresidenf, C. AV. Mally, M.vSc, F.E.S. ; Vice-Presidents,
G. Arnold, D.Sc, E.E.S./A. J. Orensteiu, M.D. ; Mevihers,
H. G. Bieijer, Ph.D., A. G. Biinton, F.R.C.S., L.R.C.P.,
Prof. E. II. Cluver, P. A., M.B., B.Cli., Prof. T. E. Dreyer,
B.A., Ph.D., Prof. II. B. Fautham, M.A., D.Sc, E.Z.S.,
Prof. E. J. Goddard. ]5.A., D.Sc, Prof. J. D. F. Gikdirist.
M.A., D.Sc, Ph.D., F.L.S., J. Hewitt, B.A., W. M.
Hewetson, M.B., DP.H., A. K. Haagner, F.Z.S., A. J. T.
Janse, F.E.S. , C. P. Lcunsbiirv, B.Sc, F.E.S. , Sir F. Spencer
Lister, M.R.C.S., L.R.C.P.,'D. T. Mitchell, M.R.C.V.S.,
H. U. Moffatt, M.L.C., Sir Arnold Theiler, K.C.M.G., D.Sc,
E. H. Strong, M.R.C.S., L.R.C.P.. W. AYatkins-Pitchford,
M.D., F.R.C.S., D.P.H., Miss M. Wilman ; Recorder, Annie
Porter, D.Sc, F.L.S. ; Hon. Secveiary, P. II. Taylor.

Section E.— ANTHROPOLOGY, ETHNOLOGY, NATIVE
EDUCATION, P II I L O LOGY AND NATIVE
SOCIOLOGY.

President, Rev. Henri A. Jnnod ; Vice-Presidents,
Mr. Justice A. F. Russell, B.A., LL.B. ; Principal A. Kerr;
Members, Rev. S. G. Gilkes Aitchison, M.A., D.D., Rev. S. S.
Dornan, M.A., Prof. C. M. Drennan, M.A., Rev. G. Evans,
Rev. J. R. L. Kingon, M.A., F.R.S.E., H. S. Keigwin, M.A.,
J. McLaren, Prof. Morgan Watkin, M.A., L. es L., Ph.D.,
Rev. E. W. H. Musselwhite, B.A., Prof. R. D. Nauta, Rev.
W. A. Norton, M.A., B. Lift., Rev. Noel Roberts, S. Sernya;
Recorder, N. H. Wilson; Hon. Secretary, Rev. Neville Jones.

Section F.— EDUCATION, HISTORY, MENTAL SCIENCE,
PRACTICAL ECONOMY, GENERAL SOCIOLOGY
AND STATISTICS.

President, Prof. R. A. Lehfeldt, B.A., D.Sc; Vice-Presi-
dents, Sir Francis Newton, Iv.C.M.G.; Prof. 0. Waterhouse,
M.A.; Members, J. E. Adamson, M.A., A. Aiken, E. Chappell,
C.B.E., Prof. J. Clark, M.A., LL.D., G. Duthie, M.A.,
F.R.S.E., S. Evans, J. A. Foote, F.G.S., F.E.I.S., Prof.
T. M. Forsyth, M.A., Ph.D., Prof. J. H. Hofmevr, M.A.,
Prof. W. S. Johnson, M.A., J. W. Jagger, F.S.S., M.L.A.,
G. T. Morice, K.C., Prof. R. Leslie, M.A., F.S.S., Prof.
W. A. Macfadven, M.A., LL.D., Miss B. Stoneman, D.Sc,
A. J. Somerville, M.A., H. A. Trubshaw, A. R. Welsh;
Recorder, J. Mitchell; Hon. Secretary, B. M. Narbeth, B.Sc

PROCEEDINGS OF THE EIGHTEENTH ANNUAL GENERAL
MEETING OF MEMBERS.

{Held in fhe Board l^oom. Library Buildings, Bulaicayo, on Saturday
July 17, 1920, at 9.30 a.m.)

Present: Dr. I. B. Pole Evans (President), in the chair, C. L.
Andrew, Miss D. Ball, Miss A. M. Bottomley, G. F. Britten, Rev. Holman
Brown, S. N. C. Collins, Dr. E. M. Delf, Prof. R. B. Denison, F. Evles,
Prof. H. B. Fantham. E. Farrar. J. A. Foote, D. F. Forsyth, Miss
Forsyth, Mrs. Gibson, Father E. Goetz, Dr. H. H. Green, C' J Gray
Lr C. Grice, Prof. P. Gundry, J. S. Henkel. Rev. H. A. Junod. E. J.
Laschinger, Prof. W. A. Macfadven. A. M. Mace;regor A. S Mclntyre
Mrs. H. M. McKay, C. W. MallV, Mrs. A. W. Marchand, Dr. B. de C.
Marchand, H. B. Maufe, Dr. A. Mavrogordato, ^Y. F. Miolee. A J. C.
Molyneux, Advocate G. T. Morice, H. G. Munday, B. M. Narbeth, Prof.
E. Newberry, Dr. E. A. Nobbs, Dr. A. J. Orenstein, Prof. A. C.
Paterson, Prof. H. H. Paine, Miss A. Robinson, Dr. A. W. Rogers,
Ven. Archdeacon F. A. Rogers, Prof. W N. Roseveare, Prof. I. J.
Roussean. Miss M. Roux, J. Sandground, Dr. T. R. Sim, S. H. Skaife,
Miss E. C. Steedman, D. P. Suttie, Prof. D. Thodav, Mrs. M. G. Thoday,
Miss M. Thomson. Prof. H. J. W. Tillvard, Dr.' P. A. van der Bijl,
G. Weeks, Prof. J. A. AYilkinson, Miss M. Wilman, N. H. Wilson,
H. E. Wood, Prof. A. W. Young and M. K. Carpenter (Assistant
General Secretary).

Minutes. — The Minutes of the Seventeenth Annual General Meeting,
held at Kingwilliamstown on July 9, 1919, and printed on pp. xxiv-xxviii
of the Report of the Kingwilliamstown Session (vol. xvi of the
Journal), were confirmed.

Annual Report of the Council. — The Annual Report of the
Council for the year 1919-20, which had been open for inspection by
Members in the Registration Room at the Eveline School, was, on the
proposal of Prof. D. Thoday, seconded by Mr. Fred Eyles, taken as read
and adopted. This Report will be found on p. xxiii of this issue.

Financial Statement and Balance Sheet for the Year 1919-1920. —
This Statement and Balance Sheet having been suspended for inspection
by the side of the Annual Report of Council, Prof. J. A. Wilkinson
moved that the same be passed, subject to audit. This was seconded by
Prof. D. Thoday and agreed to. (See pp. xxvi-xxix.)

Housing of Scientific and Technical Societies. — Prof. J. A.
Wilkinson, on behalf of Prof. J. Orr, moved tlie following motion,
standing in the name of the latter: —

" That a part of the Trust Funds of this Association be invested
with the ' Associated Scientific and Technical Societies of South
Africa.' "

In speaking to the motion, the mover outlined the scheme whereby
the Scientific and Technical Societies on the Rand had provided them-
selves with a permanent home. He enlarged upon the advantages which
would accrue to the Association by becoming a participating body, the
minimising and centralisation of secretarial woik, the provision of rest,
committee and lecture rooms, of a reading-room containing the latest
scientific and technical literature, and of facilities for meeting our own
members as well as the members of other societies. Furthermore, this
Association, by becoming a participating body, would not only gain in
standing, but would materially assist in the co-operative movement
amongst scientific societies, and thus prevent much overlapping in
expense.

Dr. A. J. Orenstein, in seconding the motion, dwelt upon the
benefits members would derive, both individually and collectively, by
the Association becoming one of the foundation members of the scheme.

Dr. E. Nobbs. Mr. C. W. Mally and Prof. W. A. Macfadyen asked
questions respecting the soundness of the scheme and whether the
proposition was such as should be submitted to the Trustees for their
consideration.

rROCEEDIXGS OF AXXUAL MEETING. xxi

After tliese queries had been answered in the affirmative by Prof.
AVilkinson, Mr. Laschinger and Dr. Orenstein, it was agreed that the
Association should becom.^ a participating body, and tlie following
amendment was proposed by Prof. Macfadyen : —

" That in the event of debentures being raised to take the place of
the first mortgage, the Trustees be authorised and j-ecommended
to invest £500 of their Trust Funds in that form."
This was seconded by Mr. C. W. Mally.

Prof. J. A. Wilkinson thereupon withdrew the original motion and
the amendment became the substantive motion before the meeting, and
was agreed to unanimously.

Election of Officers for the Year 1920-1921. — The following
Officers were elected: Fresidciit, Prof. J. E. Duerden, M.Sc, Ph.D.,
A.R.C.S.: Vice-Presidents. Prof. G. E. Corv, M.A., Prof. R. Leslie,
M.A., F.S.S., T. R. Sim, D.Sc, Prof. J. A. Wilkinson, M.A., F.C.S. ;
Hon. General Secretaries, H. E. Wood, M.Sc, F.R.Met.S., F.R.A.S.,
C. F. Juritz, M.A., D.Sc, F.I.C. ; Hon. General Treasurer. J. A. Foote,
F.G.S., F.E.I.S.; Hon. Editor of Publications, Prof. H. B. Fantham,
M.A., D.Sc, F.Z.S.

Election of Council Members for 1920-1921.— The following were
elected Members of Council for the year 1920-1921, the retiring President
Dr. I. B. Pole Evans, being also ex officio a Member of Council for the
year: —

I. Cape Province. — (1) Cape Penlnnda: Prof. L. Crawford, M.A.,
D.Sc, F.R.S.E., Dr. O. J. Currie, M.B., M.R.C.S., Rev. W. Flint,
D.D., J. Lunt, D.Sc, F.I.C, C. W. Mallv, M.Sc, F.E.S., A. H. Reid,
F.R.I.B.A., Prof. D. Thodav, M.A. (2) East London : E. Hill, M.R.C.S.,
L.R.C.P., D.P.H. (3) Kimherley: Miss M. Wilinan. (4) KinqwiUiams-
town: E. B. Dwyer, B.A.. J. Leighton, F.R.H.S. (5) Port Elizabeth:
Rev. J. R. L. Kingon, M.A., F.R.S.E. (6) SteUenbosch : Prbf. E. J.
Goddaid, B.A., D.Sc, Miss Alta Johnson, Ph.D.

II. Traxsva.\l (1) Witwatersrand: C. Aburrow, M.I.C.E., M.S.A.,

N. O. Curry, J. H. Dobson, D.S.O., M.Sc, E. Farrar, J. Gray, F.I.C,
J. A. Foote, F.G.S., F.E.I.S., W. Ingham, M.I.C.E., M.I.M.E., R. T. A.
Innes, F.R.A.S., F.R.S.E.. J. McCrae, Ph.D., F.I.C, E. T. Mellor,
D.Sc, M.I.M.M., F.G.S., J. Mitchell, .J. Moir, M.A„ D.Sc. F.I.C, Prof.
J. Orr, O.B.E., B.Sc, Annie Porter, D.Sc, F.L.S., W. Reid, F.R.I.B.A.,
(2) ]'reti,rm: Ethel M. Doidge. M.A., D.Sc. F.L.S.. B. de C
Marchand, B.A., D.Sc, E. P. Phillips, M.A., D.Sc, Sir Arnold Theiler,
K.C.M.G.. D.Sc

III. Orange Free St.\te.— Prof. T. F. Drever, B.A., Ph.D., F. W.
Storey, B.Sc, F.C.S.

IV. N.atal.— (1) Durban: J. Kirkman. J. P.. B. M. Narbeth, B.Sc.
(2) Pietermaritzburg: Prof. J. W. Bews, M.A.. D.Sc, Prof. E. Warren,
D.Sc.

V. Rhodesia. — (1) Bulawauo: Rev. E. Goetz, S.J. (2) Salisbury:
H. B. Maufe, B.A., F.G.S.

VI. Mozambique. — S. Seruya.

There are still a few vacancies, and elections to fill them will be
made by the Council.

Creation of Office of Honorary Librarian.— Prof. J. A. W^ilkinson
moved, in accordance with notice, that a new office of Honorary Librarian
be created, that the person elected he given a seat on the Council, and
that the Constitution be altered accordingly. If Members decided on
this course, he fuither proposed that Dr. Annie Porter, D.Sc, F.L.S.,
be appointed Honorary Librarian. Dr. Porter, at the request of the
Council, had been in charge of the Association's Library for some
months past.

The motion was secor.ded by Mrs. Thoday, supported by
Prof. Macfadyen, and carried unanimously.

Annual Session, 1921.— Dr. I. B. Pole Evans stated that an invita-
tion had been received from the Mayor of Durban, through Mr. B. M.

XXll PROCEEDIXGS OF AXXUAL MEJ:TING.

Narbeth, for the Association to liold it^s Annual General Meeting in 1921
at that city, and he propased that the invitation be accepted.
This was agreed to unanimously.

President, 1922. — Dr. I. B. Pole Evans proposed that Dr. A. AV.
Rogers, M.A., F.R.S., be asked to accept the Presidency of the Associa-
tion for the year 1922. This was agreed to unanimously, and Dr. Rogers
accepted.

Proposed Increase of Annual Subscription. — In the absence of
Prof. C E. Moss, and for the purpose of discussion, Prof. J. A. \Vilkinson
proposed that the meeting now proceed to consider the advisability of
increasing the annual subscription to 30s.

Mr. E. J. Laschinger seconded the proposal.

Prof. H. B. Fantham emphasised the need of more funds for the
publication of the Journal on account of tlie increased cost of materials
and labour. The Journal during the coming vear would cost at least
£1,000, probably £1,200.

Mr. B. M. Narbeth strongly opposed any increase in the annual
subscription on the grou'id that it would restrict the activities of the
Asociation by a reduction in the number of Members. He was of the
opinion tliat tlie additional money required to meet the cost of the
Journal could be raised by other means.

Dr. A. W. Rogers hoped that the Journal, v.liich served a very
useful purpose in disseminating scientific knowledge, would not be
greatly reduced or curtailed on account of the lack of funds.

The question of printing advertisements with the Journal was
mentioned as a possible source of revenue, but it seemed to ))e considered
by some Members that little profit would accrue after paying commission
and printing, unless a large numljer of advertisements could be obtained.

The possibility of increasing the annual subscription to 25s. was
also discussed.

Dr. A. J. Orenstein proposed that, in view of the increased cost of
the Journal, the matter be referred to the new Council for consideration
and definite action, if tliis were constitutional.

Mr. H. E. Vv'^cod seconded this motion, which was carried.

In the course of the discussion, Miss Steedman suggested that the
Government be approached for an increased grant. Mr. F. Eyles
suggested that the Rhodesia n Government be also approached for a
grant towards the expense of pu1)li.shing the Journal. Mrs. Thoday
recommended that agriculturalists and machinery merchants be
approached for donations for this purpose.

The meeting agreed that these recommendations be referred to the
Council.

Wireless Telegraphy. — Mi-. H. E. Wood sul)mitted the following
motion : —

" That the Government be requested to erect forthwith a wireless
telegraph station of sufficient power to receive and transmit
messages to Europe and North America, and that copies of this
resolution be sent to the Prime Minister, the Minister for
Industries and the Daily Press."

This was agreed to unanimously.

Votes of Thanks. — On the motion of Mr. C. W. Mally, it was
unanimorsly resolved that the liearty thanks of the Association should
be accorded to : —

(1) The Administrator and Ladv Chr.Dlin for their kindly interest
in the Association and for the Garden Party given in honour of its
Members.

(2) His Worship the Mayor and Town Council and Citizens of
Bulawavo for their cordial welcome to the Association, for the evening
rece7)tion. and for the general facilities afforded to the Members.

rROCEEDIXGS OF ANNUAL MEETING. - XXIU

(3) Tlic members of tlie Local Reception Committee for their
excellent arrangements for the meetinp; and for their untiring efforts
on behalf of every visiting Member of the Association.

(4) The Ladies of Bulawayo for their kind hospitality in providing
tea.

(5) The Governing Bodies" or Committees of many local institutions,
especially the Bulawayo Club, the Eveline School, the Pulilic Library
and the St. George's School.

(6) All those who provided transport for the exciirsions to the Khami
Ruins, the Cement ^Yorks and the World's View.

(7) The Boy Scouts for many favour;; to members.

(8) The Press for their efforts in bringing the work of the Association
prominently before the public.

(9) Mr. D. Niven, Secretary to the Reception Committee, for his
kindly activities in preparation for and during the visit of the
Association.

A hearty vote of thanks was unanimously accorded the retiring
President, Dr. I. B. Pole Evans, for his services during the past year. -

REPORT OF THE COUNCIL FOR THE YEAR ENDING

30th June, 1920.

1. Obituary : Your Council has lo leport, with great regret, the deaths
of the following members : — Sir Hamilton Goold-Adams, G.C.M.G.,
President of the Association 1909; Mr. Maurice S. Evans, C.M.G., President
of Section D in 1916 ; the Hon. Justice Jackson, who has taken a deep
interest in the Association for several years and was nominated as President
of Section E this year; also Mr. Jas. Bisset; the Rev. Jas. Campbell;
Dr. J. M. Coutts; Dr. J. Schlesinger Delmore ; Mr. H. G. Flanagan, F.L.S. ;
Mr. Hennen Jennings; Mr. C. D. Leslie; Senator the Hon. S. Marks and
Mr. F. S. Watermeyer.

2. Membership : Since the last report 143 new members have joined the
Association, 10 have died, and 14 have been removed from ihe registea* by
resignation or by resolution of the Council. The nett increase in membership
has therefore been 119.

The following comparative table, as from the 1st July in each year,
shows the various Provinces from which members are drawn :—

1919.

1920.

Transvaal

410

474

Cape Province

281

294

Orange Free State

Natal

Rhodesia

Mozambique

South-West Africa

Protectorata •

Abroad

Unknown

863 982

3. Change of Headquarters : In accordance with the resolution passed
at the Annual General Meeting of members at Kingwilliamstown last year,
the Headcjuarters of the Association were removed to Johannesburg. Office
and Library accommodation was generously provided by the administration
of the Public Library in their building, which is centrally situated in Kerk
Street, at the nominal rental of £2 10s. per month, and your Council desires
to place on record its gratitude for this benefaction.

4. The Journal : Unfortunately, the publication of Volume XV. of the
Johannesburg 1918 Meeting, was not completed until the end of November,
1919. Under the Editorship of Dr. .Juritz. the first number of Volume XVI.,
containing papers read at the Kingwilliamstown 1919 Meeting, was published
at the beginning of January, 1920, and the second number of that volume
at the beginning of April, 1920. Dr. Juritz at this time resigned the
Editorship, and the thanks (jf the Council were tendered to him for liis

XXIY EErORT OF COUNCIL .

services. The duties of Editor were undertaken by Dr. H. B. Fantham.
A third number of Volume XVI. appeared at the end of April, under the
designation of October-Djcember, 1919. A fourth number called January-
March, 1920, did not appear until the end of June, owing to a month's
delay in the printer's office, after the page proofs were passed. At the
present time, the galley proofs of the remaining Kingwilliamstown papers,
to form an April-July, 1920, number, are being corrected. Owing to the
great delay, it has been found impracticable to submit galley proofs of the
forthcoming issue to some of the authors, though this step was taken with
great reluctance. An index is in preparation.

In view of the high cost of printing and the paper shortage, it is
strongly recommended that either r.n annual volume be issued or quarterly
numbers. It is intended to endeavour to secure advertisements, but
commission will probably have to be paid to obtain them, and the cost of
printing them will be heavy. Even with the aid of advertisements, in view
of tlie increased cost of postage, the Editor is unable to recommend
for the present the continuance of monthly parts, which have nearl}- always
been behind their date of publication; further, such irregular publication
does not commend itself to advertisers. Money could also be saved by
condensing or omitting some of the matter usuaily printed at the beginning
of a new volume.

5. Library : The Library, as received from Capetown, was unfortunately
not in a satisfactory condition. The Journals were not arranged, nor was
it possible to find some of the books and periodicaJs listed. On the other
hand, a large bulk of old correspondence and circulars of meetings held
many years ago, was received. An enormous weight, amounting to several
tons, of the Journals of the Association, both bound volumes and separate
monthly parts, was also received. It would appear that far too many copies
of the Journal were printed in the past, except in the case of the Meetings
of 1908 and 1909. This collection of old papers and the excess number of
Science Journals involved the Association in much needless expense for
removal, and they are occupying space in the Library which could be more
usefully filled by journals and publications obtained in exchange. Attempts
are being made to utilise this excess of old literature of the Association in
obtaining further exchanges, but in these days of costly printing and a
world shortage of paper, it is very difficult to obtain new exchanges.

It appears that little has been done in the way of binding volumes in
the Association's Library for a long tim.'! past, : nd loose numbers are
deteriorating and getting lost. Money is urgently needed for binding.

6. Assistant General Secretary : Owing to the change of Headquarters
of the Association from Capetown to Johannesburg, as decided by the
resolution passed at the Annual General Meeting of members held at
Kingwilliamstown, the post of Assistant General Secretary became vacant by
the "resignation of Mr. J. P. Starke, who had held the office since the
resignation of Mr. H. Tucker, mentioned in last year's report. The Council
decided to advertise the post, and as a result 5\Ir. INI. K. Carpenter was
chosen out of 108 applicants, and he took up the:' duties of Irhe poet on
1st September, 1919.

7. Affiliation to British Association : No reply has yet been received
regarding this matter mentioned in last year's report.

8. Donations ; The thanks of the Association are due to the Hon. The
Minister of Mines and Industries for the renewal of the grant of £150 for
the year ending 30th June, 1919, towards defraying the expenses of
publishing the Association's Journal, and £50 in aid of the expenses incurred
in connection with the Annual General Meeting. A further grant of £250
was made for the year ending June, 1920, of which £150 has already been
received. In addition to the above, your Council is pleased to be able to
record its thanks to the Witwatersrand Council of Education for a grant of
£100, and to Mr. W. Ingham for a donation of £50 towards defraying the
expenses of removal of the library from Capetown to Johannesburg.

9. South Africa Medal and Grant, 1920 : On the recommendation of
the South Africa Medal Committee consisting of Professor H. B. Fantham
(Chairman), Sir Arnold Theiler, Principal Sir Carruthers Beattie, Professor
L. Crawford, Dr. I. B. Pole-Evans, Dr. H. H. Green, Professor P. Leslie.

RErORT OF COU-XCIL. XXV

Mr. C. P. Lounsbury, Professor J. Orr, Dr. i^nnie Porter, Dr. A.
W. Roberts and Professor J. A. Wilkinson, your Council has awarded the
South Africa Medal, together with a grant of £50, to Professor Ernest
Warren, D.Sc, F.Z.S., Director of the Natal Museum, Pietermaritzburg,
and Professor of Zoology in the Natal University College' (see p. xxx).

10. Closeb, Union and joint Housing of Learned Societies : It is
gratifying to be able to report that the scheme, the principle of which was
approved by members at the last Annual General Meeting, has attained
fruition, a suitable building in Johannesburg having been secured by the
generosity of the Transvaal Chamber of Mines for this purpose. As resolved.
Professors Orr and Watkin represented this Association on the Committee
dealing with this question, and it is hoped that the Association will become
a foundation member. This matter, which is of great importance, will be
discussed at the Annual General Meeting of members.

11. Zoological Survey : With respect to the resolutions mentioned in
last year's report, a conference on this matter was held in Pretoria in
January, representatives of the Clniversities, Museums, and Government
Scientihc Departments of the Union and Rhodesia being present at the
invitation of the Hon. The Minister of INIines and Industries, who opened
the proceedings. Dr. Gilchrist was elected Chairman, and the report of the
conference waS; by the Minister's request, forwarded to the Advisory Board
of Industries and Science, which has not yet reported. Your Council feels
that the time has now arrived to take further steps in this matter.

12. Reconstruction of the Union Senate : Messrs. R. T. A. Innes
and J. A. Foote were appointed a committee to communicate to the Press
an article embodying the whole course of action taken by the Association
concerning the constitution of the Senate, fiom the inception of the idea by
51 r. Watkins, of Kimberley, up to the present.

13. International Research Council : As no steps had been taken by
any Institution of Learned Societies in the Union to collaborate with the
International Research Council formed in Europe for the international
co-operation and promotion of research, your Council resolved that the
Government of the Union be recommended to become a member of this
International Council, and that the Association be grouped with it. A copy
of this resolution was addressed to the Hon. The Minister of Education,
but so far no reply has been received.

14. The New Council : On the basis of membership provided for in the
Constitution of the Association, Section VI. (d), the number of members of
Council assigned for the representation of each centre during the ensuing
twelve months should be distributed a^ follows : —

Cupe Province :

Cape Peninsula ... ... ... ... 7

East London ... ... .. ... 1

Kimberley ... ... ... ... 2

Kingwilliamstown ... ... . . ... 1

Port Elizabeth ... ... ... ... 2

Stellenbosch ... ... ... ... ... 2

Transvaal :

W'itwatersrand ... ... ... ... 17

Pretoria ... ... ... ... ... 4

Potchefstroom ... ... ... ... ... 1

Transvaal Outside ... ... ... ... 1

Orange Free State :

Bloemfontein .. ... ... ... ... 2

A^atal :

Maritzburg ... ... ... ... ... 2

Durban ... ... ... ... ... 2

Natal Outside ... ... ... ... 1

Rhodesia :

Bulawayo ... ... ., ... ... 1

Salisbury ... .. ... ... ... 1

Mozambique ... ... ... ... ... ... 1

XXVI

REPORT OF THE HONORARY TREASURER FOR THE YEAR
ENDING MAY 31. 1920.

In view of the serious nature of the finances of the Association, the Council
has requested me to pUice the following facts before the members.

The only really permanent and regular source of income which the
AsBociation possesses is that which is derived from members' annual
subscriptions. At present these amount to about £900.

The chief item of exi^puditure is that of printing and publishing the
Journal. If the JouuN.vr, iiad appeared regularly once per month, the cost
this year would have been at least £1.200.

The cost of paper, of printing, of producing illustrations, and of liinding
has increased enormously of late; and there is no prospect of any marked
reduction coming about for some time to come. On the contrary, there is
every likelihood of further increases.

Th(B Government has recently increased its postal letter charges by 50 per
cent., and this entails more office exjDenses.

The Council recently appointed a sub-committee to consider the almost
precarious condition of the finances of the Association, and the following
methods of reducing expenditure and of increasing revenue were considered : —

1. Beducing the Size of tltc Journal.- — Tt was felt that to reduce the size
of the Journal at present would be a questionable policy, as the Journal
represents the best means of retaining our present memliers and of attracting
new members.

2. Inserting Advertisements in the Journal. — Tt was decided to endeavour
to obtain advertisements for insertion in the Journal as soon as regular issues
could be guaranteed, and it was hoped that this could be done next year.

3. Increasing the Number of Members. — All members of Council were
specially urged to do their utmost to oI)tain new members. The result of this
appeal, however, has not been so satisfactory as it might have been.

4. Securing an Increased Grant from the Government. — The Minister of
Education was approached, and, as a result, the Government's grant to the
Association has been increased from £150 to £250.

5. Obtaining Private Donations. — The amount secured under this heading
now amounts to £175.

6. Increasing the Amount Fayable b]i Life Memhcrs. — The consideration
of this matter was left over for the present, but the matter should be considered
at an early date, as the payments made now by life members are much too low.

7. Increasing the Annual Subscriiition . — After much discussion, the Council
felt they had no other course oi^en to them than to request the members at the
Annual General Meeting, to be held at Bulawayo in July next, to agree to an
increase in the annual subscription from twenty to thirty shillings.

It should be mentioned that other Societies (e.g., the British Association
for the Advancement of Science, the Linnean Society of London, and the
British Ecological Society) have already found it necessary to increase their
annual subscription. In addition, the Linnean Society has, for the present,
ceased to issue its Transactions. Other Societies (('.;/., the Royal Geographical
Society) have reduced the size of their Journals. Economies hare been effected
in connection with most Journals unconnected with Societies, or the price of
such Journals has been increased.

The above-mentioned Societies Avere self-supporting before the cost of
labour and of commodities generally reached their present high level, and it
is even more essential for our Association, which is not self-supporting, to
consider, and to consider seriously, how it can reduce its expenses and augment
its income.

C. E. MOSS,

Hon. General Treasurer.

June 25, 1920.

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XXX

THIRTEENTH AWAUD OF THE SOUTH AFllICA
MEDAL AND GRANT.

{Fund raised by Meinhers of the Britisli Association in com-
viemoration of tlieir visit to South Africa in 1905.)

After the conclusion of the Presidential Address in the
large hall of the Grand Hotel, Bulawayo, on Wednesday,
July 14, 1920, the President, Dr. I. B. Pole Evans, presented
the South Africa Medal, together with a grant of £50, to
Prof. Eknest Waehen, D.Sc, Director of the Natal Museum
and Head of the Department of Zoology in the Natal TTniversity
College, Pietermaritzburg. In making the presentation, the
President said:' —

Dr. Warren was educated at University College, London,
where he studied from 1891 to 1894. He graduated first in
First Class Honours, qualifying for the Scholarship at the
London University B.Sc. examination in 1894. He was
appointed Demonstrator in Zoology at the College under the
late Professor W. F. R. Weldon. In 1898 he obtained the
degree of Doctor of Science at London University for a thesis
on the variability of the human skeleton. In 1899 lie became
Assistant Lecturer and Museum Curator at University College,
and in the same year was elected Fellow of the College. In
1903 he was appointed Director of the Natal Government
Museum, and in 1908 he was elected a Fellow of the Royal
Society of ^South Africa. He was appointed Professor of
Zoology in the Natal University College in~^1910.

Dr. AVarren has especially worked on biometrics, Coelen-
terata and breeding. Some of his chief researches may be
briefly mentioned: —

Dr. Warren undertook an extensive statistical investigation on the
variability and inter-relationships of the skeleton of an ancient
homogeneons human race from Naqada, Egypt, the remains of which
were excavated by Professor Flinders Petrie. The very numerons
measurements obtained were treated by the modern statistical methods
introduced by Professor Karl Pearson. It was demonstrated that the
dispersion of the variations about the mean could not be represented
by the normal curve of errors, but the theoretical curves which fitted
the observations were distinctly skew and had a limited range. The
variation in certain dimensions of the body of a population of a species
of crab was siinilarly treated. In order to determine the nature of the
variability and strength of inheritance in parthenogenetic generations,
breeding experiments were undertaken with Baphiiin and Ajihis. On
theoretical grounds. Weismann believed that the members of a
partlienogenetic family exhi1)ited little variability. It was conclusively
shown, however, that very considerable variation occurred and the
strength of inlieritance between the parthenogenetic mother and
offspring Avas practically the same as in sexual reproduction.

During the last few years, Dr. "Warren undertook certain breeding
experiments with nasturtiums and foxgloves. The experiments indicate
that Mendelian factors must not be regarded as fixed inimutable units,
but that they are variable in nature and can be transmitted as such to
the next generation.

An investigation on the nature of the horny teeth of lampreys and
hagfishes showed that these structures are not to be regarded as

SOUTH Al'KICA MEDAL. XXXI

degenerate calcified teeth, but rather as primitive, purely ectodermal
striictures. They mav be considered as the first stage in the evolution
of the ordinary calcified teeth of vertebrates. Dr. ^Yarren also showed
that the maxillary gland .of the free-swimming Nauplius larva of a
freshwater Crustacean, Leptodora hyaJina. was purely ectodermal in
origin and thus may be homologised embryologically with the nephridia
of Cheetopoda.

Since his appointment to the Natal Museum, in 1903, Dr. Warren
has founded and edited a well-illustrated scientific .iournal. the " Annals
of the Natal Museum," in which, in addition to contril)utions by himself,
important papers have appeared on South African biological research.

Considerable attention has lioen given by Dr. "Warren to the Hydroid
fauna of the South African coast. Many new species have been described,
and true parasitism among the Hydroids was demonstrated for the first
time.

Of a more popular character. Dr. Warren has written articles on
"Mammals and Birds of Natal," '' Soutli African Birds of Economic
Value," and various museum reports and catalogues.

The following- is a list of Dr. Warren's published papers : —

1. " Variation in rortiuiiis dcpuiator.'' Proc. Boyal Soc, London

(1896).

2. '• An investigation on the vnriabilitv of the human skeleton." Phil.

Trans. Poyal Soc, London (1898).

3. '• An abnoi-mality in Bona tempomria." Anat. Anzeiger (1898).

4. " An observation on inheritance in parthenogenesis." Proc. Porjal

Soc, London (1899).

5. " On the reaction of Daphnia magna (Straus) to certain changes in

its environment." Quart. Joirrn. Micro. Science (1900).

6. " A preliminary account of the development of the free-swimming

Nauplius of Leptodora hijalina Lillj." Proc. Poyal Soc,
London (1901).

7. " On the teeth of Myj'inc and Pet roimizon.''' Quart. Journ. Micro.

Science (1902),

8. *' On the anatomy and development of the Fluke, Vistomuin.

cirrigerum v. Baer." Quart. Journ. Micro. Science (1903).

9. " Preliminary attempt to ascertain the relationship between the

size of cell and the size of body in Daplinia magna Straus."
Jiionietrila, London, vol. ii, pt. 3 (1903).

10. " On Jiertraniid hirhnioni sp. n. a Myxosporidium occurring in a

South African Rotifer." Annah XataJ Museum, vol. i. pt. 1
(1906).

11. '• On Tuhularia solitaria sp. n. a Hydroid from the Natal Coast."

Annals Xatcd Museum, vol. i, pt. 1 (1906).

12. " On Hedocordyle cooperi sp. n. a Hydroid from the Natal Coast."

Anncds Natcd Muscu7n, vol. i, pt. 1 (1906).

13. " Note on Conroluta roscoffensis Graff collected on the Natal Coast."

Arneds Xatcd Museum, vol. i, pt. 1 (1906).

14. " Note on the abnormal hoofs of a Sheep." Anncds Xatal Museum,

vol. i, pt. 1 (1906).

15. '' On Parawrightia rohusta sp. n. a Hydroid from the Natal Coast ;

and also an account of a supposed Schizopl) yte occurring in
the gonophores." Anncds Xatal Museum, vol. i, pt. 2 (1907).

16. '■ Note on the variation in the arrangement of the capitate

tentacles in the Hydroid Iledocordyle cooperi.'" Annals Xatal
Museum, vol. i, pt. 2 (1907).

17. " Note on the larva of a Fly {Sarcophaga sp.) occurring in the

Human Intestine." Anncds Xatcd Museum, vol. i (1907).

18. " On a collection of Hvdroids mostly from the Natal Coast."

Annals Xatal Museum, vol. i, pt! 3 (1908).

19. " On Lafcea dispolians sp. n. a Hydroid parasite on Sertnla ria

hidens Bale." Annals Xatal Museum, vol. ii, pt. 1 (1909).

20. " Notes on the life-histories of Natal Termites, based on the

observations of the late Mr. G. D. Haviland." Annals Xatal
Museum, vol. ii, pt. 1 (1910).

XXXn SOUTH AFEICA MEDAL.

21. " Some statistical observations on Termites, mainlv based on the

work of the late Mr. G. D. Haviland." Blomeirika, London,
vol. No. 4 (1909).

22. " On a black, hairless duiker and dog and a bulldog-headed calf."

Annals, Xatal Museum, vol. ii, pt. 2 (1910).

23. " Mammals and birds of Natal." Article in Natal Province

Descriptive Guide and Official Hand-l)ook, 1911.

24. " On some specxiens of fossil woods in the Natal Museum." Annals

Natal Museum, vol. ii, pt. 3 (1912).

25. " A case of H.vbridism among Cockatoos." Annals Xatal Museum

vol. iii, pt. 1 (1914).

26. " On the development of the Planula in a certain species of

Plumularian Hydroid." Annals Xntal Museum, vol. iii, pt. 1
(1914).

27. •' Note on the occurrence in South Africa of a Termitophilous Beetle

of the genus Crjwtoea.'" Annals Xatal Museum, vol. iii, pt. 1
(1914). "

28. " The parthenogenetic tendency in the Moth Melanocera menippe

(Westwood)." Annals Xatal Museum, vol. iii. pt. 2 (1915).

29. •' A further note on Hybrid Cockatoos." Annals Xatal Museum

vol. iii. pt. 2 (1915).

30. " On II]i<] r'lelithjis hoycei. a Hydroid parasite on fishes." Annals

Durban Museum, vol. i, pt. 3 (1916).

31. " A i^reliminary report on some breeding experiments with Fox-
gloves." Jiiometiika, London, vol. xi. No. 4 (1917).

On the anatomy of a new South African Hydroid, Bimcria rigida
sp. n." Annals Xatal Museum, vol. iv, pt. 1 (1918).

33. " Observations on cellular degeneration and the formation of

pigment in certain Hydroids." Annals of Xatal Museuvi,
vol. iv, pt. 1 (1918).

34. " The Pure Line Hypothesis and the inheritance of small varia-

tions." S.A. Journ. Seience, vol. xv, pp. 535-567 (1918).

Previous Recipients.

1908. C rah a m st a u-n.— Arnold Tlieiler, C.M.G., V.M.D., Bacteriologist to

the Transvaal Government, Pretoria.

1909. ]{lne mf oiitei n.— Harry Bolus, D.Sc, F.L.S., of Sherwood, Kenil-

worth. Cape Division.

1910. ('ai>etou-n.— John Carruthers Beattie, D.Sc, F.R.S.E., Professor

of Physics, South African College, Capetown.

1911. 7^//r/icayo.— Louis Peringuey, D.Sc^, F.E.S., F.Z.S., Director of

the South African Museum, Capetown.

1912. ]',nt Elizabeth.— Alexander William Roberts, D.Sc, F.R.A.S.,

F.R.S.E., of Lovedale Observatory, C.P.

1913. Loureiico Mareiues. — Arthur William Rogers, M.A.. Sc.D., F.G.S.,

Assistant Director of tlie Union Geological Survey, Capetown.

1914. Kimhe rle I/.— Rudolph Marloth, M.A., Ph.D., Capetown.

1915. Pretoria. — Charles Pugsley Lounsbury, B.Sc, F.E.S., Chief of

the Division of Entomology, Union Department of Agriculture,
Pretoria.

1916. Maritzhunj.—Thomafi Robertson Sim, F.L.S., F.R.H.S., foimerly

Conservator of Forests for Natal.

1917. Stellenbaseh.— John Dow Fisher GdchrLst, M.A., D.Sc, Ph.D.,

F.L.S., C.M.Z.S., Professor of Zoologj-, South African College,
Capetown.

1918. Juliannesbunj. — Robert Thorburn Ayton Innes, F.R.S.E.,

F.R.A.S., Union Astronomer, Johannesburg.

1919. Kinuu-illiamstou-n. — James Moir, M.A., D.Sc, F.I.C., Government

Mining Chemist, Johannesburg.

ASSOCIATION LIBRARY.

The following publications are filed at the Association's Room in the
Public Library, Johannesburg.

General Science.

Royal Society of Edinburgh : Proceedings.
Royal Society of South Africa : Trarsactions.
Royal Society of South Australia : Memoirs.
Royal Society of South Australia : Transactions.
Royal Society of Victoria : Proceedings.
Royal Society of Canada : Proceedings and Transactions.
Royal Society of Tasmania : Papers and Proceedings.
Royal Society of Queensland : Proceedings.
Royal Dublin Society : Scientific Proceedings.
Royal Institution of Great Britain : Proceedings.
Royal Philosophical Society of Glasgow : Proceedings.
Royal Society gf Arts : Journal.
Michigan Academy of Science : Reports.
-Chicago Academy of Sciences :
Bulletins

Special Publications.
Reale Academia dei Lincei, Rome : Atti.
Kungl. Svenska Vetenskapsakademien :
Handlingar.
Arsbok.
Koninklijke Akademie van Wetfnschappen, 'Amsterdam :
Proceedings of the Section of Sciences.
Verhandelingen.
Real Academia de Cicncias de Madrid : Revista.
British Association for the Advancement of Science : Reports.
Australasian Association for the Advancement of Science : Reports.
American Association for the Advancement of Science : Proceedings.
Indian Association for the Cultivation of Science :
Proceedings.
Reports.
Bulletins.
Societa Italiana por il progresso delle Scienze : Atti.
Association Frangaise pour I'avancement des Sciences : Conferences.
Cambridge Philosophical Society:
Transactions.
Proceedings.
Manchester Literary and Philosophical Society : ^Memoirs and Proceedings.
American Philosophical Society : Proceedings.
University of California :
Bulletins.
Memoirs.
University of Virginia : Philosophical Society Bulletins.
Tohoku Imperial University : Science Reports.
New York Academy of Sciences : Annals.
American Academy of Arts and Sciences : Proceedings.
Tonnecticut Academy of Arts and Sciences : Transactions.
Meddelanden fran K. Vetenskapsakademien Nobelinstitut.
California Academy of Sciences : Proceedings.
Academy of Science of St. Louis : Transactions.
Academy of Natural Sciences of Philadelphia : Proceedings.
American Journal of Science.
Ohio Journal of Science.

Nova Scotian Institute of Science : Proceedings and Transactions.
Revue Generale des Sciences.

Archives Neerlandaises des sciences exactes et natnrelles.
Annaes scientiiicos da Academia polytechnica do Porto.

^XXIV ASSOCIATIO-V LIBRARY.

Pihodesia Scientific Association :

Proceedings.

Annual Reports.
Societe de physique et d'histoire natureile de Geneve :

Memoires

Comptes rendus.
Det Kongelige Norske Videnskapers Selskaps Skrifter.
Kongelige Danske Videnskabernes Selskab : Uversigt.
Vierteljahrsschrift der naturforschenden Gesellschaft, Zurich.
Imperial Institute : Bulletins.

New Zealand Institute : Transactions and Proceedings.
Annual Report of the Smithsonian Institute.
Annual Report of the Smithsonian Institution (United States National

Museum).
South African Museum :

Annals.

Annual Reports.
Transvaal jNIuseum : Annuals.
Natal Museum : Annals.
Queensland Museum :

Annals.

Memoirs.
Field Museum of Natural History Publications.
University of Pennsylvania Museum .Torrnal.
Public Museum of Milwaukee : Bulletins.
Albany Museum :

Annual Reports.

Records.
Knowledge.
Science.

Franklin Institute : Journal.
University of Minnesota : Current Problems.

Chemistry. ^Metallurgy, and Geology.

Chemical, Metallurgical, and Mining Society of South Africa : Journal.
Kungl. Svenska Vetenskapsakademien : Arkiv for Kemi, Mineralogi, och

Geologi.
Geological Society of South Africa : Transactions.
Geological Society of Tokyo : Journal.
Geological Survey of New South Wales : Reports.

Memoirs.

Mineral Resources.
Geological Institution of the University of Upsala : Bulletins.
Geological Society, London : Abstracts of Proceedings
Bulletins of the Wj'oming State Geologist.
United States Geological Survey :

Annual Reports.

Mineral Resources.

Bulletins.

Monographs.

Professional Papers.
Florida State Geological Survey : Annual Reports.
Servico geologico e mineralogico do Brasil : ]\Ionographias.
Union of South Africa Mines Department : Annual Reports.
Canada Department of Mines :

Museum Bulletins.

Memoirs of the Geological Survey.

Reports.
New South Wales Department of Mines : Annual Reports.
The Mineralogical Magazine.

Egyptian Ministry of Finance : Geological Reports.
Geological Survey of Western Australia :

Annual Progress Reports.

Bulletins.
Journal of Industrial and Engineering Chemistrv.

ASSOCIATION LIBEARY. XXXV

Journal of Chemical Technology.

The Chemical News.

University of Minnesota : Studies in Chemistry.

South African Association of Analytical Chemists : Proceedings.

Meteorology,

Royal Meteorological Society : Quarterly Journal.
Mount Weather Observatory : Bulletins.
Observatorio Campos Eodrigues :

Relatorio.

Resumo mensal.
Egyptian Ministry of Finance : Meteorological Reports.

Agriculture

Regia Scuola superiore agricoltura di Portici : Annali.
International Institute of Agriculture, Rome :

International Crop Report and Agricultural Statistics.

International Review of the Science and Practice of Agriculture.

Documentary Leaflets.

Statistical Notes on the Cereals.
Massachusetts Agricultural Experiment Station :

Annual Reports.

Bulletins.
Maine Agricultural Experiment Station: Annual Reports.
Agricultural Gazette of New South Wales.

Department of Agriculture, New South Wales : Science Bulletins.
United States Department of Agriculture :

Experiment Station Record.

Year Book.
New York State College of Agriculture and Experiment Station :

Annual Reports.
Journal of Agricultural Research.
Rhodesia Agricultural Journal.

Revista de Agricultura, Comercio y Trabajo, Cuba.
Bulletin Agricole de I'Algerie-Tunisie-Maroc.
Station agronomique de la Guadeloupe : Bulletin.
Union of South Africa Agricultural Journal.

Biology and Physiology.

Bulletin de la Societe Imperiale des naturalistes de Moscou.
Kungl. Svenska Vetenskapsakademien :

Arkiv for Botanik.

Arkiv for Zoologi.
Journal of the Linnean Society, Botany.
Bulletin of the W^isconsin Natural History Society.
The Medical Journal of South Africa.
University of California : Publications in Botanv.
Linnean Society of New South Wales : Proceedii gs.
Missouri Botanical Garden :

Annual Reports.

Annals.
Bolus Herbarium : Annals.
Smithsonian Institution (United States National ^Museum) : Contributions

from the United States National Herbarium.
Royal Botanic Gardens, Kew : Bulletins.

Union of South Africa : Reports of tlie Director of Veterinary Research.
The Australian Zoologist.

LTniversitv of INIichigan, Museum of Zoology :
^liscellaneous Publications.
Occasional Papers.
Lloyd Library :

Bibliographical contributions.

Mycolf)a:ical Notes.
South African Biological Society : Bulletins.

XXXVl ASSOCIATIOX LIBRAE Y.

Entomology.

Bulletin of Entomological Research.
Review of Applied Entomology.

Bacteriology.
Abstracts of Bacteriology.

Astronomy, Mathematics and Physics.

Royal Astronomical Society

Memoirs.

Monthly Notic3S.
Journal of the Eoyal Astronomical Society of Canada.
Harvard College Astronomical Observatory :

Circulars.

Annals.

Annual Reports.
Leyden Sterrenwacht : Annalen.
Union Observatory Circulars.
Cape Observatory :

Annals.

Reports.

Cape Astrographic Zones.
Observatoire Royal de Belgique ; annuaire astronomique.
Khedivial Observatory, Helwan, Egypt : Bulletins.
Kodaikanal Obsei-vatory : Bulletins.

Kodaikanal and Madras Observatories : Annual Reports.
British Astronomical Association.

Journal.

Memoirs.
Lick Observatory : Bulletins.
Nizamiah Observatory : Reports.
Astronomical Society of India :

Journal.

Monthly Notice's.
United States Naval Observatory Publications.
American Ephemeris and Nautical Almanac.
Western Australian Astronomical Society : Proceedings.
Kungl. Svenska Vetenskapsakademien : Arkiv for Matematik, Astronnmi

och Fysik.
London Mathematical Society : Proceedings.
Tohoku Mathematical Journal.
National Physical Laboratory, ^Middlesex :

Collected Researches.

Reports.
University of Minnesota : Studie.'! in the Physical Sciences and Mathematics.
Universidad Nacional de la Plata : Contribucion al estudio de las Ciencias

fisicas y matematicas.
Physical Society of London : Proceedings.

Education \L, Political Economy and .Sociology.
United Empire.
South Africa.

Ohio State University Bulletin.
International Institute of Agriculture, Rome : International Review of

Agricultural Economics.
Royal Dublin Society : Economic Proceedings.
Athenfeum subject index to Periodicals.
Municipal Journal of South Afnca.
Universitv of Minne.sota :

Studies in Economics.

Studies in Public Health.

Studies in the Social Sciences.

Geoge.aphy, Oceanography and Hydrography.
Societa Italiana per il progress© delle Scienze : Comitato talassografico :

BoUetinos.

Memorias.

ASSOCIATION LIBRARY,

XXXV II

The Geographical Journal.

The Geographical Review.

United States Geological Survey : Water Supply Papers.

Egyptian Ministry of Finance : Survey Department Papers.

Instituto di geografia fisica e vulcanologica della R. Universita di Catania ;

Pubblicazioni.
United States Department of Commerce, Coast and Geodetic Survey :

Special Publications.

Annual Reports.

Engineering.

Proceedings of the American Institute of Electrical Engineers.

Journal of the South African Institution of Engineers.

Transactions of the South African Institute of Electrical Engineers.

South African Society of Civil Engineers : Proceedings.

South African Engineering.

University of Minnesota : Studies in Engineering.

Technology.

Patents for Inventions : Abridgments of Specifications.
The Illustrated Official Patents Journal.
South African Journal of Industries.

Anthropology and Ethnology.
Journal of the African Society.
University of Minnesota : Studies in Language and Literature.

Archeology.
Bulletins of the Archaeological Survev of Nubia.

XXXVUl

OFFICEKS AXD COUNCIL, 1920-21.

Honorary President:

1[IS MAJESTY THE KING.

President:

Prof. J. E. DuEKDEN, M.Sc. Ph.D.

Ex-President:

B. Pole Evans, M.A., D.Sc.

Vice-Presidents:

Prof. G. E. Cory, M.A.
Prof. R. Leslie, M.A.

T. R. Sim, D.Sp.

Prof. J. A. WiLK.NSON,

M.A.

Hon. General Secretaries:

H. E. Wood. M.Sc.

Union Observatory,

Johannesburg.

Hon General Treasurer:

J. A. FooTE. F.O.S.,

Commeifial High School,

Johannesburg.

Hon. Librarian:

An.nie Porter, D.Sc,

S.A. Institure for Medical Research.

Johannesburg.

C. F. JiiRiTZ. M.A.. D.Sc.

Agricultural Chemical Research

Laboratory, Capetown.

Hon. Editor of Publications:

Prof. H. B. Faniham, M.A., D.Sc.
University College,

Johannesburg.

Assistant General Secretary:

H. A. G. Jefereys,

P.O. Box 6394. Johannesburg.
(Telegraphic Address : " Science.")

Ordinary Members of Council:

I.-

-CAPE PROVINCE.

('((/)(■ Peninsula.
Prof. L. Crawford, M.A., D.Sc.
O. J. Currie. M.B.. M.R.C.S.
Rev. W. Flint, D.D.
J. LuNT, D.Sc.
C. W. Mally, M.Sc.
A. H. Reid, F.R.I.B.A.
Prof. D. Thoday, M.A.

E(it:t London.
E. Hill, M.R C.S. L.R.C.P., D.P.H.

Kimberlcij.
Miss M. Wilman.

Kingirillid m ^toicn.
E. B. Dwyi;r, B.A.
J. Leighion, F.R.H.S.

Port Elizahcth.
Rev. J. R. L. KiNGON. M.A.

StcUen^iosch.
Prof. E. J. GoDDARD B.A., D.Sc
Miss Alia Johnson. Ph.B.

II.-TRANSVAAL.

Witiratcrsrand.
C. Aburrow. M.I.C.E.

P. CAZ.ALET, M.I.M.M.

E. A. E. Collins.

N. O. Curry.

J. H. Dobson. D.S.O., M.Sc

E. Farrar.

J. Gray. F.I.C.

v.. Ingham. M.I.C.E., M.I.M.E.

R. T. A. INNES. F.R.S.E., F.R.A.S.

J. McCrae. Ph.D.. F.I.C.

E. T. Mellor, D.Sc

J. Mitchell.

J. MoiR, M.A., D.Sc.

Endoirmrnt Fund.

Principal Sir J. C. Beattie, D.Sc
J. W. Jagger, F.S.S., M.L.A.
W. RUNCIMAN, M.L.A.

Advocate G. T. Morice, K.C, B.A.

A. J. Orenstein, M.D.

Prof. J. Orr. O.B.E., B.Sc, M.I.C.E.
Walter Reid, F.R.I.B.A.

Pretoria.
Miss Ethel Doidge, M.A.. D.Sc.

B. DE C. Marchand, B.A.. D.Sc.
E. P. Phillips, M.A., D.Sc.

Sir Arnold Theiler, K.C.M.G., D.Sc.

F. G. Tyers,

Potchefstroom.
M.A.

Transvaal- Outside.

A. W. Rogers, Sc.D., F.R.S.

III.— ORANGE FREE STATE.
Blocmfontein.
Prof. T. F. Dreyer, B.A., Ph.D.
F. W. Storey, B.Sc.

IV.— NATAL.

Durban.

J. KiRKMAN, J. P.

B. M. Narbeth, B.Sc.

Pietc rm a ritzh u rg.
Prof. J. W. Bews, M.A., D.Sc.
Prof. E. Warren, D.Sc.

V.-RHODESIA.

Balairayo.
Rev. E. Goetz, S.J., M.A.

Salisbury.
H. B. Maufe. B.A.

VI.— MOZAMBIQUE.

S. Seruya.

Trustees:

.S..4. Medal Fund.

J. DE V. Roos. B.A.. LL.B.

W. Thomson, M.A.. B.Sc. LL.D.

W. J. ViLJOEN, M.A., Ph.D.

THE VELD: ITS EESOURCES AND DANGERS.*

I. B. Pole Evans, M.A., D.Sc, F.L.S.,

I'lIKSIDKNT,

Chief, DlvisiO)i of Boianij if PUnit Puthologij und Diicctur of ilic
Botanical Survey, Ui}io)i of SoiitJi Afriea.

With Plates I— XXVIII, and 1 Map.

Presidential Addresi^ deJicercd Julij 14, ll>2n

As is customary on occasions like this I have several short
and time-honoured digressions to make before coming to the
subject of my address First of all it is. my painful duty to refer
to the loss which the country has sustained, since we last met,
in the death of two distinguished South Africans. One of these
was a past President of this Association, Sir Hamilton
Goold-Adams — formerly Governor * of the Orange Free State —
who took the chair at the meetings of this?, Association at
Bloemfontein in 1909. Sir Hamilton was keenly interested in
science and all its applications, and anyone who reads his
presidential address, delivered just over ten years ago, cannot help
being forcibly impressed by the wisdom of his words and the
urgent need which then existed for their application.

Then in the death of General Botha, not only South Africa,
but the world at large has sufferi'd a very grievous loss. Although
the first Union Premier was not a member of this Association he
took a most active part in the scientific development of the
country, and as one who speaks from personal experience, having
been privileged to serve under him, I can say without fear of
contradiction that he ha* been largely responsible for the rapid
agricultural development of the Union through the unstinted and
encouraging support which he always rendered his technical
advisers. He gave more than careful and sympathetic
consideration to any reasonable proposals for the advancement of
the country's prosperity. Although he is regarded by the majority
only as a great politician, in reality he was nnbued with the true
scientific spirit, and like Science herself took no cognisance of
race, nationality or party where questions of truth, knowledge and
the world's welfare were concerned. His was a marvellous
personality, he was everyone's friend. Ill can South Africa and
Science in general afford to lose s.o noble a statesman.

Secondly, I wish to convey to the members of this Association
my very great appreciation of the honoau" which they have done

* Illustrated by lantern slides from the author's photographs.

2 rRESIDENX's ADDRESS.

me in electing me to the Presidential Chair, and 1 trust to their
kindlj' forbearance in overlooking any shortcomings m my attempt
to fill worthily so responsible a position.

Finally, it is with unbounded pleasure that I extend to you,
Mr. Chairman, and to the citizens of Bulawayo our deep
appreciation of the compliment you have paid us in inviting us
to return tO' this city when so short a period has elapsed since our
last visit. South Africa is essentially a country of surprises, and
1 feel is destined to become one of rapid progress. I am sure,
therefore, that after we have availed ourselves of your cordial
hospitality, those of us who were here some nine years ago will
leave your "land of ancient ruins" more impressed than ever
with its surging progress, its vast potentialities and the enormous
possibilities which exist for the application of science in all its
phases.

As regards this Association the period since we last met here
has been one of steady progress, and its objects are being slowly
but surely achieved. In this connection I can not do better tlian
refer you to the able review of the Association's history and
activities given by Prof. John Orr in his Presidential Address at
Stellenbosch some three years ago. I cannot, however, refrain
from drawing particular attention to the remarkable growth in
the nuinber of papers which in the past few years have dealt with
some aspect of biology. This m.ay be taken as a sign of the
times, and might be quoted as an encouraging symptom, showing
that South Africa is fully alive to the importance of the study
of the biological sciences.

In looking through the list of our past Presidents, I find that
Botany has only once before been honoured with the Presidential
Chair. This was some six years ago, at Ivimberley, when our
distinguished botanist, Dr. Marloth, presided over the meeting
and was at the same time awarded the Society's medal for his
services to Botanical Science. Dr. Marloth took as the subject
of his address — " Some Problems of Botanical Research in South
Africa" — and his opening sentences were as follows: —

" I shall, for the sake of convenience, deal first with
such questions as are specially connected with the material
welfare of the country. It is too often overlooked that there
is nothing of greater importance to us in a country than its
vegetation, that the vegetation ;>f a country is tlie basis of
all life, and withovit :t neither animal nor man could live
there, unless maintained by artificial means and imports."

Well may we pause and ask ourselves how many of us realise
to the full the significance of these words. Those of us who toil
in the Public Service know to our cost the views held by the
average pedantic otficiab. who regards the study of botany as an
expensive hobby, to be looked upon with condescending tolerance
rather than as a vital necessity of an agricultural country and as
such demanding every support and encouragement. If some of
our oflficials are still diill and antiquated in this respect, we can

riiESIUEXT S AIJDRESS. O

congratulate ourselves that our landowners, legislators, and
labourers are alive to its vast importance and in recent years have
taken steps tO' provide facilities for the study of the vegetation
of the country. South Africa has during the last few years
attained so worthy a place in the ranks of scientific progress that
a well-known scientific publication recently referred to " the
enlightenment of outlook in matters connected with the bearing
of scientific knowledge on practical affairs, which experience has
taught us to expect on the part of the Government of the Union
of bouth Africa."

Marloth in his address alluded to the many problems awaiting
investigation, pointed out the difficulties under which the early
botanists laboured and drew attention to the backwardness of
South Africa as compared with other countries with regard to
facilities provided by the State for botanical research. He was,
however, suthciently alert to detect a silver lining to the cloud,
and mentioned, among other things, the recent establishment of
the National Gardens at Kirstenbosch, and the provision of graats
for research by the Union Government.

Although it is only six years since his address was delivered,
considerable progress has been made in the interval, and I
propose briefly to take up the subject where Marloth left it, and
give a short resume of what has been done since those days.
First and foremost, the Government of the Union of South Africa
has established a Botanical Survey for the purposes of which the
Union has been divided into definite areas. The survey of each
area, is being carried out under the supervision of an experienced
botanist, and funds are pro'vided by the State to give facilities
for research and survey to those working in co-operation with the
botanists in charge. This is a great step in advance of former
times and is one of which those botanists who worked together in
loyal co-operation have every reason to be proud. It is also
pleasing to report that the progress already achieved is more than
gratifying and assuring.

While the State has been carrying out its obligations to the
country, I think I shall have no' difficulty in convincing you that
the workers — few though they are — have not been backward in
doing their part.

During the period under review Marloth has continued his
magnificent work on the flora of South Africa, Bews has made
an exhaustive study of the vegetation of Natal, Pearson has
botanically explored South-West Africa, and Schonland has
published a Memoir on the flora of Uitenhage and Port Elizabeth.
Mrs. Bolus is engaged on a study of the flora of the Cape
Peninsula, Phillips has made a botanical survey of Basutoland,
French Hoek and the Great Winterhoek, and Hepburn has
published a paper on the flora of Herschel.

In addition to the description of botanical regions detailed
above a number of monographs on genera and families of
phanerogamic plants have been published, or are in course of

4 rKKSIDENT S A1)])KKSS.

preparation. Schonland has worked up one of the most important
iamilies of succulents, the Crassulaccac, and has revised the genus
Rhus and is making a study of the Cypcraceae. Mrs. Bolus is
studying the Mcsembiyanthonuiiis, while Pillans, another worker
in the South Western area, is busy with the Restiaccae. Phillips
has added to our knowledge of the S.A. Proteaceae and has pub-
lished monographs on the genera Calpvrnia, Cyphia and Borbonia;
in collaboration with Kotze he has reviewed the genus Faurea,
and Pteronia in collaboration with Hutchinson. Miss Verdoorn,
one of the assistants in the National Herbarium, has worked on the
Transvaal Primnlines and the genus Fagara. From the economic
standpoint one of the most important pieces of work is the veld
burning experiments which Pliillips has in hand at Groeiikloof,
near Pretoria, and on which he has published a preliminary
report. Also' of great importance from an economic standpoint
is the work which is being carried out by Miss Stent on indigenous
grasses and their distribution throughout the Union and on the
plants poisonous to stock.

In addition tO' the workers mentioned above who are making
a study of the distribution and classification of plants, there are
a large number of enthusiastic and careful collectors who have
rendered valuable assistance and who have donated their
collections to public institutions. One of the foremost of these
is Mr. E. E. Galpin, who has presented his unique herbarium of
Transvaal and Cape plants to the National Herbarium and is now
making further collections and studying the vegetation of the
Waterberg District of the Transvaal. Amongst numerous other
collectors might be mentioned Madame Dieterlen whose
Basutoland plants form an invaluable addition to the National
Herbarium, and ]Madame Borle and the Rev. Junod who are
making exhaustive collections in Portuguese East Africa. Dr.
Eattray, Miss Guthrie, and J. D. Keet have made their
contributions from the Cape Province, Pierce is collecting in
Swaziland, IMogg is specialising in areas, where cattle diseases are
prevalent, E. G. Bryant, Mrs. Jones, and Miss McCallum are
keenly interested in Transvaal plants, Potgieter and Putterill
have done useful work in the Free State, and Archdeacon Rogers
is well known as an enthusiastic and intelligent collector. Mr.
F'red Eyles has added very considerably to O'ur knowledge of the
flora of Rhodesia and has published a valuable list of the plants
known to occur in that country.

Although the bulk of the work accomplished has been in
connection with the phanerogamic flora, the study of the
cryptograms has. not been altogether neglected. Sim is making a
study of the mosses and hepatics and has published the first
section of his monograph on the subject. A study of the fungi
of the country is greatly facilitated by the unique and invaluable
collection in the cryptogamic section of the National Herbarium,
which is assuming vast proportions under the care of Miss
Bottomley. I have continued my study of the rust fungi, having
published a paper on the rusts affecting the Compositae, and in
collaboration witli jNIiss Boftomlev have written on the genera

PKKSIJ)KXT S ADDRESS. O

Dililocjjstif; and Brooiucia and have compiled a list of the fungi
collected by Miss Pegler at Kentani. Miss Pegler has been one
of the keenest and most enthusiastic of the collectors who have
contributed valuable specimens to the cryptogamic lieii)aiium ;
others who' have made important contributions are Cruden, also
in the Eastern Province, Eyles and Swynnerton in Ehodesia,
Junod in Portuguese East Africa and Potts in the Free State.

Van der Bijl has made a study of the Polyporaceae. Several
papers have been published dealing particularly with the economic
aspect of this group and their influence on the forest vegetation,
and a contribution to our knowledge of the distribution and
classification of the group will be laid before the present meeting.

Dr. Ethel Doidge is devoting lier attention to certain groups
of the Ascomycetes and has published several papers dealing with
the South African species of Enjsiphaceae, Perisporiaceae and
Microthyriaceae.

I should not omit to mention, with deep regret, that during
this period our ranks have been depleted by the death of that
strenuous and able botanist, Pearson, of that careful and
enthusiastic collector, H. G. Flanagan, and of W. Tyson, who has
made large and valuable collections of marine Algae. We have
alsO' lost during the past year Maurice Evans, whose name will
always be associated with that of Medley Wood in Natal. On
the other hand we wish to welcome to our midst such well-known
colleagues as Professors Moss, Thoday and Compton, and Mrs.
Thoday (M. G. Sykes).

I must no'W proceed to' the subject of my address. To one
whose duties are of a wide and varying character the choice of a
subject must alwaj's be somewhat bewildering. For from the
nature of things where the subjects are numerous the knowledge
of each can but be superficial. My duties include the supervision
of the Botanical Svu-vey, advice on all matters of a botanical
nature, and the investigation, prevention, control, and
eradication of plant diseases within the Union. It is
obvious that much of this work carries me into the
veld, and I have therefore had exceptional opportu-
nities ot making observations on the veld throughout
South Africa during the past 15 years. Many oi these journeys
have been of a very hurried nature, but by means of the series of
photographs which I have accumulated, and some of which I
hope to put on the screen, I have obtained a general knowledge
of the veld conditions in some of the less known parts of the
country. I propose therefore to give briefly some account of: —

The Veld : Its Eesources and Dangers.

It is hardly necessary to attempt to explain to a South
African audience the meaning of the word " veld," but in order
to avoid misapprehension I may say that by the word " veld " I
mean merely the nat iral vegetation of the country. The word
therefore implies not only the plant growth of any locality, but
also has reference to' the habitat in which the plants grow. The

teesident's addeess.

study of the veld is not new, it has received considerable attention
at the hands of the botanists and travellers from the earliest
times. Some 17 years ago- Marloth gave this i\ssociation an
admirable account of these early explorers, including such men as
Burchell, Drege and Rehmann, and in that magnificently
illustrated work " Das Kapland " published in 1908, he reviewed
in detail the valuable additions to our knowledge of the veld
which have been made by Bolus, Medley Wood, and Sim; and
at the same time places on record a vast accumulation of facts
embodying his own detailed observations.

The main types of vegetation throughout the world are largely
determined by rainfall and climate, and as both of these are
influenced by the topography of the country any attempt to
classify the different types of veld must take all these facts into
consideration. I therefore consulted my colleague Dr. Rogers,
Director of the Geological Survey, who at once kindly furnished
me with a map and an account of the chief physical features of
South Africa. He recognises three main physical features. —

I. The Interior Plateau.
II. The Great Escarpment.
III. The country between the Great Escarpment and
the sea.

I. — The Interior Plateau.

In the Interior Plateau Rogers recognised ten main regions : —

1. The High Veld.

2. The Middle Veld.

3. The Upper Karroo.

4. The Basuto Highland.

5. The Limpopo' Highland.

6. The Bushveld.

7. The Kalahari and Bushmanland.

8. The Kaap Plateau.

9. The Namaqua Highland.

10. The Low Country (including much country below
the escarpment).

The country below the escarpment he divides into four
regions : —

1. The Great Karroo.

2. The South-Eastern Region.

3. The Folded Belt.

4. Coastal Belt.

These divisions were, of course, made from a consideration of
their geological formation, altitude and past geological history.
If, however, they are examined from the point of view
of the vegetation it- will be found that they form a very satisfactory
basis for the division of the country into plant regions, and many
-of the divisions correspond very closely with vegetation maps of

PRESIJJKNT S AI)])RKSS.

South Africa published by Bolus, ]\Iarloth and myself. I propose
now to give a brief characterisation of each botanical region to
show that the main types of vegetation occurring in South Africa
are intimately associated with the physical features of the
country, and shall then deal with each region in somewhat
greater detail. (See map on page 9.)

1. The Coast Veld. — Identical in extent with portions of
Dr. Eogers' coast belt, a region of drowned valleys and sandy
dunes which are covered with dense impenetrable bush, tall
grasses and palms. Isolated evergreen forests are frequent.

2. The Lo2c Veld or low country. — A region of low relief, of
wide open river valleys with perennial streams and deep alluvial
soils, which are covered with gigantic thorn and other deciduous
trees beneath which a rank growth of grass persists.

3. The Eastern Grass Veld. — Including the South-eastern
region, the Great Escarpment and the Basuto Highlands, a region
of terraced landscapes and deep valleys with perennial streams.
The soil is well covered with a grassy turf in which scattered
thom trees occur in the more open country and evergreen forests
in the sheltered kloofs^.

4. The Bushveld. — A region of flat low-lying country with
perennial streams and deep soils. It is covered witli grass, hut
well overgrown with deciduous bush and trees.

5. The Middle or Banhen Veld. — A region of gently sloping
hills, from which more or less straight belts or escarpments of
harder rock project'. The hill slopes are covered with grass, while
the rocky belts are clothed with stunted deciduous trees and
sclerophyllous bush.

6. The High Veld. — A region of vast rolling tablelands, of
horizontal strata and deep soils which are covered with a dense
grassy turf and devoid of indigenous trees and bush ; well supplied
with perennial streams.

7. Tlie Fictershurg Highveld. — An undulating plateau of
deep sandy soil, covered with grass and scattered bush.

8. Tlie Waterherg Sandveld. — A mountainous tract of
country, devoid of perennial streams, and with shallow, sandy
soil which is covered with grass. On the hill slopes there are
scattered deciduous trees and sclerophyllous bush.

9. The Griqualand West Thorn Veld. — A region of long, open
river valleys — the chief of which are the valleys of the Dry Harts,
the Harts and Vaal Rivers — with deep alluvial soil and gravels
which support- a park-like growth of thoi-n trees and tufted grasses.

10. The Kaap Plateau B^isli Veld. — A region composed of an
extensive dolomite and limestone plateau, devodd of rivers but
well supplied with pans which are usually dry. The soil is
shallow, and covered with bush, xerophytic shrub, shrublets and
grass.

11. The Vaal Kameeldoorn Veld of the Asbestos Mountains.
— A region of undulating country, stony and rooky hills, sandy

» PRESIDENT S ADDRESS.

plains and dry river valleys. The hills are covered with scrub
in which the Ijstervark bos (Lebcckia macracantlia) and Vaal
bos {Torclionanthus camplioratus) predominate. On the sandy
plains there are grass and Vaal Kameeldoorn, while the low-
lying valleys support a growth of " bralc " and xeropbytic
shrublets.

12. TJie Kalahari Sand Veld. — A region of undulating sandy
plains and dunes, dry river beds and internal drainage. In some
places the plains support only a growth of brak plants, on others
grass and thorn trees, while the dunes are covered with coarse
grass and isolated Witgat trees.

13. The Damaraland Thorn Veld. — A region of mountainous
country with a dry and arid appearance. The vegetation is
composed mainly of thorn bush and succulents, with a scanty
clothing of grass.

14. The Kavieeldoorn Veld of Scuth Damaraland. — A region
of vast deep sandy plains which support a park-like growtli of
gigantic thorn trees, below which low thorn scrub and scanty
grass subsist.

15. The South Western Veld. — A region of mountainous
character with a great variety of soil and climate, in which the
vegetation is composed mainly of sclerophyllous bush and
shrublets, with an abundance of bulbous and sedge-like plants
(Restiads).

16. The Karroo. — A region of low-lying relief in the north,
but somewhat broken in the south by the Cape ranges,
characterised by dry river beds, shallow soils and rock-exposed
surfaces. The vegetation is composed mainly of succulents,
bulbous and tuberous plants.

17. The Upper Karroo. — A region of wide plains broken by
table-topped hills and spitzkops, with dry river valleys, shallow-
soils and rocky surfaces. The vegetation is composed of
low-growing and scattered xerophytic shrublets.

18. The Kokerboom Veld of Na7}iaqualand and BusJimanland.
—A region of vast arid plateaux and plains, dry river beds and
bare stony or sandy surfaces. The vegetation is scanty and
consists of isolated tufts of grass, stunted bushes and shrublets
on the plateaux and plains, and the Kokerboom (Aloe dicJiotoma)
and Giftboom (Euphorbia virosa) on the rocky hills.

19. The Namib or Western Littoral Belt. — A region of
drifting and shifting sand dunes, of gravel plains and barren rock
surfaces. The vegetation is extremely scanty and consists of a
few grasses and succulents on the dunes and gravel plains, of
xerophytic shrubs and succulents on the rock surfaces, of the
Narras (Acanthosicyos horrida) and Tamarisk (Tamarix articnlata)
on the submerged river mouths and of the Aggenys Euphorbia
(E. gregaria) in the open valleys.

PRP;.Sir)K.VT S AIIDRKSS.

-Map showing Distribution of Types of Veld in South Africa.

10 president's addkess.

I.— The Coast Veld {Plate I).

Fringing the shore and covering the littoral dunes from Algca
Bay to our northern boundary is a type of veld more luxuriant
and tropical in character than that seen in any other part of
South Africa.

This is due to the fact that the rainfall along this coast belt
is heavier than elsewhere, the greater portion of it falling during
the summer months. The temperature along the coast is
comparatively uniform and sub-tropical; frosts seldom, if ever,
occur.

This type of veld extends from the sea-level to an altitude O'f
about 1,000 feet, and is comiposed mainly of dense bush and
evergreen forest patches. Growing just at and above high water
mark in the loose sand is the Scaevola lobelia and Ipomaea hiloba
association, and between this and the dense bush the sand is often
covered with Gazania uniflora, Cyperus naialensis, Cyanchum
ohtusifolhim, Passerina ericoides, Samolus porosus, Osteospermuni
moniliferum, Dimorphotheca fruiicosa, Strelitzia augusta, Phoenix
reclinata, Hyplianc crinita, Braclujlana discolor and Carissa
grandiflora.

The Coastal bush ranges from 10 to 30 ft. in height, and
forms a dense almost impenetrable growth, in which such trees
as the Eed Milkwood (Mimusops caffra), the Thorn Pear {Scolopia
Zeyheri), the White Pear (Apodytes dimidiata), the Wild Coffee
{Kraussia lanceolata), the Kaffir Boom {Erythrina caffra), the
Bitter Blaar {Brachyloena elliptica), the Kaffir Plum
(Harpepliyllum caffrum), the Saffraan (Elaeodcndron croce^im),
Schmidelia erosa, Euclea natalensis are woven together by
climbing plants such as Vitis capensis, Entada natalensis, Dregea
fiorihinida, Heliniiii ovatus, Sciitia ConDuersouH , FlageUarin
guiniensis and Greuna lasiocarpa. Closely associated with this
bush, but usually growing on the inland side and in more open
country, is the tlat-crown Alhizzia faxfigiata which is typical oi
this buish veld.

Wherever lagoons occur along the coast the mangroves
(Avicennia officinalis, Rliizopliora mucronata, and Bruguiera
gymnorrhiza) are characteristic of the mud swamps, while
Hibiscus tiliaceiis fringes the edge of the river estuaries.

There are several important forests in this East Coast Veld.
Chief amongst these are the forests in the neighbourhood of East
London, which are peculiar in that they consist in places of almO'St
pure associations of Cape Box {Bu-rus MacOirani), the Saffraan
(Elaeodcndron croccum), the Sneezewood {Ptacroxylon utile) and
Umbiza (Umbiza Listeriana).

The Manubi Forest, which is situated a little further north
along the coast, contains most of the trees common to the forests
of the Transkei and in addition yields fine specimens of
Umzimbeet (Millctia caffra). Cape JMahogany (Trichilia evietica)
and Essenho'Ut (Ehebergia capensis).

Still further north the Egossa forest occupies a coastal belt
of about 20 miles in Pondoland, north of Port St. John, and is
about two miles in width. Conspicuous trees in the Egossa are

rilKSIiJENl's ADDRESS. 11

the Beukeuliout (Faurca McNaiightonii), the Cape ^Mahogany
[Trichilia oiictica), tlie Umzimbeet (MiUctiii caffra), the.
Umkunye (MiUetia SiitlierJandi), the Bastard White Ironwood
(Cyclostemon arqutus) and the Cape Ebor.y (Heyivoodia lucens).
In spite of the high rainfall in this, region, it is not devoid of
succulents, and several interesting and typical species are found
there. The chief amongst these in the southern portion are two
species of Euphorbia {E. grandidcns, E. tetiagona) and Aloe
africana. Euphorbia ingens and Aloe Thraskii occur in the north.

The chief economic products of the Coast Veld are: —

1. Timber from the Cape Box, Sneezewood, Saffraan, Vlier,
Unitiza, \Yhite ^lilkwood, Kaffir Plum, White Ironwood, Cape
Mahogany, Umzimbeet, Wild Chestnut, Red Currant, Hard Pear,
and Cape Ebony.

2. Tanning materials from the mangroves : — Avicennia
officinalis, Ehizopiiora mucronata, Bniguicra gijmnorrhiza and
Ceriops Candolleana.

3. Fibre weaving materials fro^m the palms Phoenix reclinata
and Hyphcene criniia, and also from Urcra tenax and the so-called
Wild Banana, Strelitzia aiigusta.

4. Rubber from Landolphia Kirliii and Eitpliorbia Tirucalli.

5. Oil from Telfaria ped-ita and TrichiUa emetica.

2.— The Low Veld (Plates II, III).

The Low Veld comprises the country situated in the north-
eastern comer of the area under review. It inckides part of the
northern and north-eastern Transvaal, the southern corner of
Portuguese East Africa, the eastern portion of Swaziland, and
the greater part of Zululand. The Tugela River forms the
southern boundary, while the Limpopo must be taken as its
northern limit so far as this address is concerned.

On the whole the Low Veld consists mainly of flat low-lying
country, which ranges from an altitude of 400 ft. tO' 2,000 ft.
above sea level. It is well supplied with perennial streams and
rivers, amongst which the most important are the Tugela, the
Umhlatusi, the Umfolosi, the Pongola, the Maputa, the
Umbelusi, the Komati, the OHfants, the Letaba and the Limpopo
with their tributaries.

Between the two boundaries just mentioned, the Low Veld,
except for a narrow coastal strip, stretches from the Indian Ocean
on the east to the foothills of the Great Escarpment formed by
the Drakensberg Range on the west. In the extreme iiorth,
where the Limpopo Valley has worn through the range, the Low
Veld extends for some little distance behind the Escarpment, as
far as the valley of the Crocodile River.

The larger portion lying between the Great Escarpment and
the Indian Ocean is traversed almost throughout its. entire length
by the Lebombo Range, a low-lying range of mountains which
run almost due south and north.

Apart from this range of mountains the general unifonnity
of the country is seldom broken, except here and there by a few

12 rRKSIJ)ENT S ADDEKSS.

out-cropping kopjes usually composed of massive boulders of
granite. The rainfall in this area varies very considerably and
may be from 70 inches in the eastern portion to 15 inches in the
extreme western.

The general aspect of the veld is park-like, that is to say, \i)
is covered witJi tree.s which vary m height from 30 tO' 50 ft., but
which are sufficiently far apart to allow means of existence for a
dense growth of grass, undershrubs and herbs. Along the river
valleys the vegetation is much more luxuriant in character.

Inland lakes, pans, and lagoons are also not uncommon in
this area.

The greater part of the vegetation in the Low Veld can be
described as a Thorn Veld, in which the Knoppiesdoorn {Acacia
pallens) is one of the most characteristic and dominant trees,
especially in the dry open country. Other common trees typical
of the Low Veld are: — The Maroola {Sclerocarya caffra), the
Tambootie {Excoecaria africana), the Jakhalsbossie (Diospyros
mespiliformis), the Hardekool {Combretu>n porphyrolepis), the
Waterhout (Syzygiinn rordatum), the Van Wyk's bout
(Bolusanthus speciosiis) the Boerboom [Scliotia hrachypetah),
the Huilbos {Peltuphonim africanum), the Silckelbos
(Dichrostachys nutans), the Haaken-steek (Acacia spirocarpoides),
the Fever tree (Acacia xanthopliJoea), the ^Nlingerhout (Adina
Galpini), the liuikpcul (Acacia arabica var. kraiissiana),
Loncliocarpus inossa)nbiccnsis and Androstacliys Johnsoni.

On the deep alluvial flats in Portuguese East Africa the
Mahogany tree (Afzelia quanzensis), the Rooi Essehout (Trichilia
cmetica), the Sausage-tree (KigeJia pinnata) the Hardepeer
[Stryclniofi Henningsii) and Brachystegia appendiculata occur
more frequently.

At liigher altitudes just below the foothills of the
Drakensberg the Kajatenhout (Pterocarpus erinaceus) and
Bastard Kameel Doom (Acacia lasiopetala) are common, the
former often becoming the most abundant tree in the veld. With
these two the Grijsappelboom (Parinarium mobala) is frequently
associated.

On the Olifaiits. Eiver, Croton Gubonga is plentiful along the
banks, while Terminalia pruinoides and Balsa modendron
Africanu)}) dominate the bush in the drier valleys.

In the Limpopo Valley in the Northern Transvaal the
Baobab (Adansoriia digitata) and Mopane (Copaifera mopane) are
characteristic of the Low Veld.

The Low Veld is undoubtedly the most fertile tract of
country in South Africa. Its variety of soils and sub-ti'opical or
tropical climate render it eminently suitable for agricultural
purposes.

Sugar is the main crop cultivated in the southern portion,
while much of the land towards the north is suitable for ranching
and the cultivation of fibre and oil crops.

The natural resources in this area include much valuable
timber, wliicli is yielded by sucli trees as the Kajatenhout —
Piciornrpiis rrinaccus, the ^Mahogany Afzelia quanzensis

piiesidknt's address. 13

Mull., the Ebony Diospyros mespiliformis Hochst. , the Kooi
Essehout TricJiilia emetica Valii., the ^Nlingerhout Adina Golpinii
Oliv., the White Pear Apochjtes dimidiata E. Mey., and the
bastard ironwood Cijclostemon arcfUHtus Muell. Eirst-rate timber
for poles and mine props can be obtained from the Knoppiesdoco,
Acacia pollens, or from Acacia Welivitschii and Acacia rostrata.

Tanning materials are obtainable from at leaiSt three different
kinds of Mangrove, viz. : — Rhizophora mucronata Lam.,
Bruguiera gymnorrhiza Lam., and Ceriops Ca^idolleana Arn.
Trees of Acacia Bcnthami are extremely plentiful throughout the
area and yield an abundance of pods w^hich serve as a valuable
article for tanning purposes and also as a cattle food.

Fibres are obtained from the bark of the trees Ficus utilis
Sim, and Seciiridaca loiigipcdiDiculata Fres., and from the stems
of Hibiscus cainuthiniis and otlier members of the order
Malvaceae.

The tall grasses in this region furnish material which is
eminently suitable for paper-making.

The fruits of Trichilia emetica Vahl., Ximenia americana
Linn., and XantJwxyluni capense Sim., all yield a high percentage
of oil.

Landolphia Kirkii, Dyer, which occurs from the Umhlatusi
in Natal to the Limpopo, yields excellent rubber, while gums of
good quality might well be obtained from the different species of
Acacia, Comhretum, and Commiphora.

3.— The Eastern Grass Veld {Plates F, VI).

Lying between the coast veld and the Great Escarpment,
fro^m an altitude of 1,000 ft. upwards, is a fairly extensive tract of
terraced country, well covered with grass, which may be termed
the Eastern Grass Veld.

The Sundays River may be taken as its southern l)oundary,
while its northern limit extends to the Tugela River Valley and
is cO'Utinued thence along the north-eastern slopes and foothills
of the Drakensberg.

The country on the whole is much dissected by streams and
rivers which rise on the Great Escarpment and flow direct to the
Indian Ocean. In the south the veld produces many plants
which are typical of the Cape, the Karroo' and the Karroo boschjes
veld, while in the north many tropical forms occur.

The average rainfall throughout the region is between 25 and
40 inches, most of which fallsi during the summer months, and
as both rainfall and temperatvu'e increase northwards, the
vegetation becomes correspondingly more luxuriant.

The Eastern Grass Veld may be sub-divided into a lower and
upper region — The Thorn Veld and the Berg Veld respectively-

The Thorn Veld occupies the country between the coast veld
and the foothills O'f the escarpment up to an altitude of 4,000 ft.,
while the Berg Veld comprises the vegetation on the eastern
slopes of the escarpment from 4,000 ft. upwards. The former is
frequently referred to as " sweet veld," while the latter is spoken
of as " sour veld. "

14 president's A])])11ESS.

The dominant grasses in the Thorn Veld are Eragrostis plana,
Sporobolus indicus, Theyneda triandra, Andropogon hirtus, A.
pcrtusus, A. uDiplcctens, and .4. Schoenanfltus.

The thorn bush which gives the country a park-hke
appearance is chiefly the sweet thorn {Acacia Karroo). Other
common trees and bushes occurring in the open grass veld are
Acacia caffra, A. Benthami, Dichrostachys nutans, Celasfrus
bnxijolius, Elirctia lioffcidofica, Trichilia Diegeana, PtacroxyJo)i
utile, Zizyphus mucronata, Erythrina caffra, Cussonia spicata,
and Sclcrucanja caffra.

In the sheltered i^loofs on the south-eastern slopes of the
thorn veld thick bush frequently occurs. Of the larger trees in
this bush the chief are Covibrcturn Kravssii, Calodcndron capense,
Xynialos monospora, Celtis kraussiana, Pygaenm africanum,
Ficus natalensis, Podocarp'tis Thvnhergii, and Rhus longifolia.

Typical and conspicuous succulents in the southern portion
of the thorn veld, are the Spekboom (Portulacaria afra), the
Naabooms (Euphorbia grandidens and E. tetragona), and the
Alwijn {Aloe ferox), while the Naaboom {Euphorbia' Tirucalli),
Aloe Marlofliii, Aloe candelabriDn and Aloe lufcns'nre cliaracteiistic
of the northern portion.

The Berg Veld or " Sour Veld " including the Basuto
Highlands is characterised by the presence of scattered Protea
bush in the grass, and yellow-wood forests in the sheltered kloofs.
The chief grasses in the " sour veld " are the Eooi Grass
(Themcda triandra), Andropogon ccresiaeformis, Tristachya
leucothrix, Trachypogon polymorphus and Harpechloa capensis.

Taller grasses in moist situations are the Tambootie Grasses
i Andropogon nardus var. marginatus and .1. fiUpendulus).

Towards the top of the escarpment the grasses tend to grow
more in tufts and tussocks than below.

Closely associated with the Proteas in the escarpment are
the tree ferns {Cyathea Drcgii) and Kaffir bread trees
(Encephalartos ghellinchii) .

The chief trees composing the yellow-wood forests are
Podocarpus elongata, P. Thunbergii, Olea laurifoUa, Myrsine
vielanophleos, Rhus Icevigata and KiggeJaria dregeana.

In addition to the yellow-wood bush or forest, one of the most
conspicuous plant associations in the Berg Veld is the Oudehout
[Leucosidea sericea) sci*ub which occurs throughout the
Drakensberg range.

The Eastern Grass Veld embraces the most important forests
in South Africa, viz,, those that are situated on the slopes of
the Kaga Berg, the Great Winterberg, and the Amatola Mountains
and their foothills. They include the Katberg, Amatola and
Perie forests.

These forests are good examples of mixed forests, although
the larger portion of the trees are composed of the common and
the true Yellow-woods {Podocarpus elongata and Podocarpus
Thunbergii), the latter occurring in the higher regions, the former
on the lower slopes of the forest.

trksidext's address. 15

Other common timber trees in these forests are the Black
Ironwood {Olea JaurifoJia), the Assegai (Curtisia faginea), the
White Pear (Apodytes dimidiata), the White Ironwood {Toddalia
lanceolata), the Eed Currant [Rlius IcEvigaia), the Lemon Wood
(Xymalos monospora), the Thorn Pear {Scolopia Miindtn), the
Eed Els (Ciinonia capensis), the Red Milkwood (Minusops
obovata) and 8neezewood (Fiaeroxylon utile).

Next in size and importance in this area are the forests of
the Transkei, Griqualand East and Pondoland. Chief amongst
these ai'B the Zuurberg Forests. Tliey occupy a large belt ot
country on the Transkeian Zuurberg Rai-ge. The forest is very
similar in co-mposition to that on the Amatolas, except that the
Black Stinkwood {Ocotea bullata) is here more frequent.

The forests of Natal and the Transvaal are alsO' confined to
the higher slopes of the Drakensberg and differ little in
composition from those of the Transkei and Pondoland.

In some of the Transvaal forests the Cabbage Tree
{Anthoclcista zambcsiaca) frequently occurs, but it is more
abundant in the Low Veld forests of Swaziland.

The Eastern Grass Veld is rich in natural resources. Many
valuable timber trees occur in the forests, including the Common
and Real Yellow-woods, the Black Ironwood, the Assegai Wood,
the White Pear, the White Ironwood, the Red Cun-ant, the
Sneezewood, the Black Stinkwood, and the Cabbage Tree.

Tlje " Sweet Veld "' is eminently suitable lor pasturage, and
amongst the pasture grasses occurring in this region may be
mentioned: — Eragrostis plana, Eiagrostis curvula^ var. valida,
Themeda triandra, Panicum laevifoliwm, Tricholaena rosea and
T. setifolia, Setaria sulcata, Pennisetum unisetum, Pennisetum
Tliunbergii, Pennisetutn sphacelatutn, Pennisetum typhoideum
and Sporobolus indicus.

There are also' a number of grasses suitable for paper-making,
including the turpentine grass (Cymbopogon excavatus), the
lemou-scented grass (Cymbopogon naidus validus), Andropogon
liirtus, Andropogon Scliocnantlius, A. Drcgeanus, and Themeda
triandra.

Aloe ferox. Aloe Marlotliii and Aloe candelabrum are valuable
as medicinal plants.

A number of plants in the eastern thorn veld have been
found to be poisonous to slocli, the chief of these are Crotalaria
globifera and Crotalaria dura the cause of Jagtziekte, Matricaria
7iigellae folia causing bovine staggers, the Natal Slangkop, Urginea
niacrocenfra, and the blue and yellow tulps.

4.— The Bush Veld (Plates VII, VIII).

The Bush Veld occupies a narrow strip of country which
traverses the centre of the Transvaal. It is roughly about 300
miles long and 80 miles broad.

On the north it is bounded by the Waterberg and Pietersburg
plateaux, on the south by the Banken Veld and on the east by
the angle of the Great Escarpment, while on the west and north-
west it merges into the Kalahari and the Low Veld of the

lU phesidext's ajjukess.

Lim'popo Valley. On the whole it is a low-lying tract of country,
which has an elevation of 2,500 to 4,000 ft., although in the
eastern portion the elevation varies considerably and is some
6,y00 It. on the Lulu range, while at the junction of the
Steelpoort and Olif ant's Eiver it is only 1,800 ft. above sea level.

The eastern portion consists of broken and hilly country,
while the centre is flat and undulating. In the west the general
uniformity of the land surface has been interfered with by past
volcanic activity of the Pilansberg.

The rainfall varies considerably in this area, and is erratic
in its distribution. In the low-lying valleys to the east it is
extremely scanty, over the central portion it ranges from 20 to
30 inches per annum, and becoines rather less to the west. The-
soils thro'Ughout are mostl}' deep and sandy, but large areas are
also composed of black "turf" soil, which is typical of this
region.

The " turf " usually only supports grass and thorn bush,
whereas grass, trees and bush cover the sandy soils. Bush veld is
characterised by a fairly uniform growth of bush, which ranges
from 15 tO' 30 ft. in height. As a rule there is considerable space
betwee-n the trees and bushes, but the country is of such a nature
that without a compass it is extremely difficult to find one's way
or bearings when surrounded by bush on all sides. The character
and composition of the bush varies considerably. Thom trees
dominate the veld throughout, but in the broken country to the
east arborescent Nabooins (Euphorbia ingens and E. Couperi) are
the most characteristic trees. The thorn trees consist chiefly of
the Haak-en-steek {Acacia spirocarpoides), the Kameeldoorn (.4.
Giraffae), the Haakdoorn (.4. detinens), the Doornboom (.4.
Karroo), the Aapiesdoorn (.4. Burhci), the Kaffir Wacht-een-bietje
(^4. caffra), the Ruikpeul [A. Benthami), Acacia hebeclada, the
Sikkelbos (DicJirostaclnjs niitaiis) and the Huilbos (Pcltoplionini
africanum).

Other typical trees are the Wilde Sering (Burkea africana),
the Beukenhout (Faurea saligna), the Vaalboom (Terminalia
sericea), the Maroola (Sclerocarya caffra), the Wonderboom
(Boscia Rchuianniana), the Drolpeer (Doinbcya dcusifiora), the
Olijvehout (Olea verrucosa), the Red Ivory (Rhamnvs Zeyheri),
the Guarri (E^iclea nndidata), the Oliepitten {Pappea capensis),
the Zuurpruim (Ximenia americana), the Respies (Heeria
panicuJata,), the Eooibosch (Couibrctum Guenzii and ('. Zcylicri),
the Kiepersol (Cussonia panicidata, C. spicata and C. natalensis) ,
the Blinkhlaar wacht-een-bietje (Zizy pints mucronata), the
Vaalbos {Tarchonanthus camphoratus), Odina discolor, Kirkia
Wihnsii, and Ochna pulchra.

Typical succulents in this area, apart from the Xaabooms-
{Euphorbia ingens and E. Cooperi), are Eupliorbia Tirucalli, Aloe
Marlothii, Aloe Wickensii, Aloe Pienaarii, Aloe globnligemma.
Aloe Greatheadii, Aloe Davyana, Aloe castanea, and Aloe
transvaalensis.

In the western portion of the Bush Veld, in addition to the
thorn trees mentioned above, several species ol Kareeboom (Rhus
lancea, R. Gueinzii and R. incana) are conspicuous in the veld.

prksidext's address. 17

The comniun grasses of the Bush Veld are Thcmcda friandra,
Elionurus argente^is, Panicum obscurens, Chioris virgata, Chloris
petraea, Panicum Jaevifoliuni, Cymbopogon nardus, Cymbopogon
pliirinodis, Crossotropis grandiglumis, Andropogon hirtus,
Andropogon liirtifiorus, Eragiostis superba, Eragrostis brizoides,
Eragrostis curvula, Eragrostis chloromclas, Trachypogon
poJyniorplius, Urchjfru))t sqiiarrosuiii , Tristacli ya Icvcotlirix,
Triraphin rcliDUDi ni , Cyiubopogoii Rii preciifii, Tristnclnjd
rchmanni, Cyntbopogon auctua, Pcnuisction ccnchrvidcs.

In the Bush Veld timber is obtained from the Aapiesdooni,
the Wilde Sering, the Beukenhout, the Maroola, the Vaalboom,
the Drol l^eer, and the Red Ivory.

The Berg Bastj the Elandsboontjes, the Doornboom, and the
Huikpeul yield tanning materials.

Fibre is obtained from the Wilde Stok Eoos, and from
Triiuiifcttu rlioDiboidcu, Sida rhoinbijolia and Sanscvicria Dcserti.

The seeds of the Zuurpruini (Ximenia cafjra) and the
Oliepitten (Pappea capensis) are rich in oil.

Excellent grazing and pssturage for stock is provided by the
Rooi Grass (Themeda triandra), Sorghum versicolor, Tricholaena
rosea, Tricholaena setifolia, Andropogon amplectens, Panicum
laevijolium.

Paper-maliing material is furnished by the Dek Grass
[Andropogon Jiirtiflorus), Cymbopogon Buchanani, Cymbopogon
Dregeanus, Trachypogon polymorphus, Cymbopogon Ruprechtii,
Tristachya Rehmanni and Cymbopogon aiictus, and valuable
gums may be obtained from Combretum erythrophyllum , and
Co)nbretum Zcyhcri.

5. — The Banken Veld {Plate IX).

In the broken hilly country between the Bush Veld and
High Veld is a type of veld which is commonly known as Banken
Veld or Banken scenery. It consists mainly of grass covered
slopes on which stunted deciduous trees and sclerophyllous bush
occur on the rocky outcrops or " banken."

The grasses include many of those which are common to both
Bush Veld and High Veld, while the trees and bush consist
mainly of the Rooibosch (Combretum Zeyheri), the Wilde Sering
(Burkea africana), the Kaflfir Wacht-een-bietje (Acacia cafjra), the
Kiepersol (Cussonia spicata, C. paniculata and C. natalensis),
the Witstinkhout Boom (Celtis rhamnifolia), the Guarri (Euclea
lanceolata), the Witte salie (Nuxia congesta), the Klipels
(Plcctronia Mundtiana), the Suikerbos (Protea abyssinica and P.
Jiirta), the Blinkblaar (Rhamnns prunoides), the Olie Pitten
(Pappca capensis), the Boog (Croton gratissimiis), the Karee
(Rhus lancca), the MIspel (Vangueria infansfa), the Praamdoorn
(Fagara capensis), the Klapper (Strychnos pungens), the
Stamvruchte (Chrysophylhim m.agaUsmontanuvi), and the Wild
Apricot (Landolphia capensis).

The common succulents include Aloe Marlothii, Aloe
Davyana, Aloe transvaalensis, and Aloe Pretoriensis, the Honde
■oov (Cotyledon orbicnlata), Kalanchoe thyrsiflora. Euphorbia
Bchinzii and Senccio orbicularis.

18 PEESIDEXt's ADDRESvS.

On the whole, the Banken Veld affords poor grazing and
pasturage for stock, and the trees and bushes are as a rule too
small and stunted to be of much value for timber In some
places ElepJiantorrhiza Bm'kei is fairly plentiful and the bark ia
eagerly sought after for local tanning purposes. The Bergbast
(Osyris abyssinica) and the Elandsboontje {Elephantorrhiza
Burchellii) are also common and are used for tanning.

The Banken Veld abounds in one of the most deadly stock
poisons kno'wn in South Africa, the Gift-blaar {Dichapetalum
cymosum), which nearly every spring causes considerable loss
amongst cattle.

Other poisonous plants include the Gift-bol {Buphanc ioxi-
caria), and the Hondeoor (Cofu'lcdon orhiciila-ta).

G. — The High Veld (Plate X).

The High Veld includes, the southern portion of the Transvaal
and practically the whole of the Orange Free State. It is bounded
on the north by the Banken Veld, on the east by the
Drakensberg Kange, on the south by the Upper Karroo, and on
the west by the Valleys of the Vaal and Harts Eivers. It is a
high-lying tableland whose average height above sea level is
between 4,000 and 5,000 ft., with a gentle slope to the west.

The rainfall varies from 35 inches in the eastern portion to
25 or 20 in the western.

Throughout the greater portion of the area the underlying
rocks are parallel with the surface, while the soil is mostly deep
and of a loamy nature.

The surface is covered with grass, which forms a distinct turf,
except towards the western and southern boundaries, where it
becomes more open and the grass forms tufts and is often
associated with small shrublets. Indigenous trees are entirely
absent in this area, except on broken or rocky ground, and along
the sides of the streams.

The dominant grass covering the veld is the Rooi Gras
(Themeda triandra), other common grasses are Andropogon cere-
siaeformis, Andropogon amplectens, A. kirtiflorus, A. schirensis>
Axonopns semialatus, Cymhopogon elegans, Digitaria eriantha, D.
tricholaenoides, Panicum yiatalense, P. serratum, Eragrostis
hrizoides, E. clialcantlia, Cynodon Dactylon, Tristachya Ecli-
manni, Harpccldoa capcnsis and Panicum laevifolium.

Common shrublets and herbaceous plants which grow
amongst the grass are the Elandsboontje (ElcphantorrJiiza
BurcJielUi), Vigna angustifoJia, Rhus discolor, Pentanisia
variabilis, Acalypha dcpressinervis, Pachycarpus scJiinzianus,
Vangueria pygfnaca, Pacliystiqrna Zeyheri, Gerbera discolor, G.
piloselloides, Berkheya setifera, Gazania pygmaea, Arctotis
scaposa, Senecio latifolius, 8. serra, 8. coronatus, Dimorphotheca
spcctahilis, Heliclirysum floccosuni , Vernonia hraiissiif V.
monocephala, V. natalensis, 8cabiosa Columbaria, Becium
obovatum, Clerodendron triphyllum, Ipomaea GreenstocMi,
Gnidia 7nicrocephala, Erythrina Zeyheri.

prksi])ent's address. 19

Tuberous and bulbous plants common amongst the grass
include Brachystehxa foetidum, Raphionacme divaricata,
Euphorbia truncata, Eulophia rohusta, Bupliane toxicaria.
Gladiolus rigidifoliiis, Hypoxia costata and Hatcorthia tenuifolia.

The common trees along the streams and rivers are the
Doornboom (Acacia liairoo), the Wilgeboom {Salix capmsis), and
the Vaterlands wilg {Comhretnm cnjthrophyWum).

The High Veld affords excellent grazing and pasturage for
all kinds of stock. The chief pasture grasses are the Rooa Gras
{Thcmeda triandra), Digitaria criantha, Panicum natalensc,
Panicwm Jcevifolium, Panicum serratum, Tricholaena rosea,
Triciiolaena sctifolia, and Cijnodnn dactylon. Other valuable
fodder plants include Trifoliuni afiicanu)n and Ipomaea
Greenstockii.

The chief poisonous plants of the High Veld are the TuIpSi
(Homeria pallida) and Moraca spp., which are poisonous chiefly
to cattle, and Pachystigma pygmaca, which, during certain
seasons, causes heavy mortality amongst sheep.

Overstocking on the High Veld invariably results in the veld
becoming overrun with Stocbe cinerea, which crowds out the
pasture grasses.

7 AND 8. — The Waterberg Sand Veld (Plate IV) and
The Pietersburg High Veld.

The Limpopo Highlands as delimited by Rogers include the
high-lying country which lies to the north and east of the northern
extension of the Drakensberg. They comprise the Waterberg,
Pietersburg, and Zoutpansberg plateaux, with their surrounding
country. Three distinct plant regions are recognisable : (1) A
western portion, which may be called the Waterberg Sand Veld,
occupied mainly by the Waterberg plateau is, on the whole, hilly
and rugged country with scanty and sandy soil. The sandy
valley's are mostly covered with grass, in which Elionurus
argenteus, Eragrostis superba, and tall species of Andropogon are
common, while the dominant trees are the Beukenhout [Faurea
saligna) and Suikerbos (Protea abyssinica) on the stiff close-
grained soils and the Vaal boom [Terrninalia scricea) on the deep,
loose, sandy soils. The deadl}' Giftblaar (Dichapetalum.
cymosum) is extremely plentiful in this region and is nearly
always, associated with the Wilde Sering.

(2) An eastern portion, comprising the Pietersburg plateau,
and which may be termed the Pietersburg High Veld, consists
chiefly of flat rolling country, which resembles typical High Veld
scenery, and on which the Eooi Grass (Themcda triandra)
dominates. To the south the plateau slopes away to the
Busli Veld, and as soon as the altitude drops to 3,000 ft., grass and
vegetation gives way to bush.

To the north the grassveld of the Pietersburg plateau merges-
into the thorn veld of the low country of the Limpopo Valley. It
is characterised by the dominance of Acacia pallens, A.
spirocarpoides, A. karroo and Combretnm porpliyrolepis.

20 president's address.

(3) The northern portion of the Zoutpansberg phiteau, which
is composed of parallel ranges of sandstone, lies at a lower altitude
than the Water berg and Pietensburg plateaux. The vegetation is
similar to that of the Low Veld, and from a ph^^togeographical
point of view may be included in the Jatter region.

0. — The Griqualaxd West Thoux Veld (Plate XI).

In the centre of the inland plateau and bounded on the south
by the Orange Eiver, on the west by the Kalahari, and on the
east by the High Veld, is a somewhat triangular block of country
which is usually included under the term " The Kaap Plateau."
Botanically this region is perhaps less known than any other part
of tlie inland plateau, but from what little information is available,
its affinities undoubtedly lie with the western portion of the
plateau rather than with the eastern.

The whole area falls naturally into three distinct types of
veld. The eastern portion consists of long, open river valleys (the
valleys of the Dry Harts, Harts and Vaal Piivers), with deep
alluvial soils and gravels, which are covered with a park-like
growth of thorn trees and tufted grasses. This I shall describe as
the Griqualand West Thorn Veld.

The central portion, the Kaap Plateau proper, consists of an
extensive dolomite and limestone plateau of shallow soils which
are covered with bush, xerophytic shrubs and shrublets. This I
shall refer to as the Kaap Plateau Bush Veld.

Between the Kaap Plateau Bush Veld and the Kalahari is a
tract of undulating veld composed of stony and rocky hills, sandy
plains and dry river valleys. The hills are covered with bush and
scrub, the sandy plains with grass and the Vaal Kameel Thorn,
^hile the low-lying valleys contain many brak and xerophytic
shrublets. This tract of country I have included under the title
" The Vaal Kameel Veld of the Asbestos Mountains."

The Griqualand West Thorn Veld includes the valleys of the
Orange, Vaal, Harts and Dry Harts Pvivers lying in the districts
of Herbert, Kimberley, Barkly West, Bloemhof, Taungs, and
Vryburg.

The veld isi park-like throughout. This type of scenery is
produced by various thorn trees growing amongst Karroo bush and
grass in the south, but chiefly amongst grass only in the north.

The common thorn trees are the Haak-en-steek {Acacia:
spirocarpoides), the Kameeldoorn (Acacia Girafjae), the Doorn-
boom (Acacia Karroo), the Haakdoorn (Acacia dcfincns) and the
TerassibO'S (Acacia stohnifcra).

Other typical trees, bushes, and shrublets found in this veld
are the Witgats (Boscia albitrunca and Boscia transvaalenfiis),
the Vaal Bos (Tarchonanthus camphoratus), the Blauwbosch
(Roycna pallens), the Driedoorn (Rhigozum triciiotoynum), the
Zuur-karree (Rlivs ciliata), the Eozijntjebosch (Greicia cana), the
Bitterbossie (CJirysocoma teniafolia), the Schaap Bos (Penfzia
incana), and the Harpuis-bos (Euryops multifidvs).

Typical and dominant grasses are Sclnnidtia hidbosa, Cldoris
virgata, Eragrostis Iclimanniana, Aristida adsccnsionis, Eragrostis

rRESIIJENT's A])1)11KSS. 21

tnincata, Panicum Marlothii, Themeda triandra, Eragrostis
demidata, AnthepJiora pubescens, Fingerlnithia africana, Panicum
Hohibii, Eragrostis superba, Aristida congesta, A. brevifolia, A.
Burkei, A. uniplumis, A. stipiformis, A. niolUssima, Pogonarthia
falcata, Tragus koelerioides, and Chrysopogon serridafus.

Other characteristic plants occurring in this region are the
Wilde Kalabas (Hibiscus urens), the Wild Senna [Cassia obovata),
the Cape Slangkop (Ornithoglossum glaucuiii), the Slangkop
(Urginea Burkei), the Dubbeltjedoorn (Tribvlus terrestris and T.
zcyheri), the Stijfziekte Bos (CrotaJaria Burkeana), the Gousblom
(Gazania uni flora), the Pakkiesblom [Herinannia brachypetala),
the Duiveitjea (Pretrea zanguebarica), the Kriedoon (Lycium
tetrandrutn), and the Vomeerbossie (Geigeria passerinoides).

Tulps are extremely plentiful and often give the veld a blue
or yellow hue due to Moraea polystachya and Homeria pallida.

The chief succulents are Aloe grandldentata and Aloe
Schlecteri var. Orpcniae.

The pasture and hay grasses of the Griqualand West Thorn
Veld are practically the same as those found on the Kaap plateau.
One of the most important poisonous plants is Ornithoglossum
glaucutn, the Cape Slangkop. Lebeckia psiloloba is suspected of
poisonous properties, and Tribulus terrestris, under certain
conditions, produces Geel dik-kop in sheep.

In the tliorn veld of the Harts River Valley, Acacia Giraffac
is plentiful and the pods of this tree provide an excellent stock
food.

10. — The Kaap Plateau Bushveld (Plates XII, XIII).

The Kaap Plateau Bushveld occupies the wide limestone
plain which stretches froan a little south of Griquatown to the
north of Vryburg. On the east it is bounded by the escarpment
of the Campbell Rand, which overlooks the valleys of the Vaal
and the Harts Rivers, and on the west by the Asbestos and
Kuruman Hills.

The whole area is remarkably flat, and is characterised by the
presence of numerous pans, whose floors are composed of
tufaceous limestone. The surface of the ground is hard and
uneven and consists very largely of dolomite outcrop. Here and
there, however, soil of a sandy nature occurs.

The plateau throughout is covered by bush or scrub which
ranges in height from 6 to 15 ft. This bush is composed mainly
of the Olijvehout (Olea verrucosa), the Zuurkaree (Rhus
tridactxjla) , the Haakdoorn (Acacia detinens) and the Vaalbos
(Tarchonanthus camphoratus). The Haakdoorn is dominant in
the south, the Olijvehout and Zuurkaree in the central portion,
and the Vaalbos in the north.

Karroo bush, composed of L'Jiiy.socoina tcnuifoUa and Pentzia
incana, is mainly associated with the Haakdoorn, the Olijvehout
and the Zuurkaree on tlie shallow dolomite outcrops, while grass
veld is more commonly associated with the Vaalbos where the
Boil is sandy and deeper.

22 pkksiukm's address.

The dominant grasses are the Eooi Gras (Themeda triandra),
Eragrostis Ichmanniana, and Aristida spp.

Often associated with Olijvehout and the Zuurkaree are large
trees of the Kareeboom (Elms vi^ninaUs) and the Bhnkblaar
wacht-een-bietje (Zizyplms mucronafa).

The blue tulp (Moraea polystachya var. hrevicaidis) is
extremely common throughout the plateau, as well as the Trans-
vaal Slangkop Urginea Burhci. The latter is iiearly related to' the
European plant producing " squills " and may be of equal
medicinal value. Crotalaria Burkeana is prevalent in this region,
and is the cause of Stijf-ziekte in cattle. The Vormeer-bosje
[Geigeria passcrinoidcs) is another well-known jooisonous plant in
this area.

The most important timber trees are the Wild Olive ( Olea
verrucosa), the Transvaal Beukenhout {Faurea saligna), and the
Transvaal Kajatenhout {PeltupJtuium africanum). Large tracts
of country are covered with Euryops multifidus, a plant which is
becoming a pest to stock farmers, as it is crowding out the pasture
grasses, but which yields a resin which might be exploited
commercially.

The principal pasture and hay grasses in this region are
Eragrostis lehmanniana, ScJimidtia hiilbosa, Themeda triandra,
Eragrostis brizoides, E. cbtusa, E. superba, E. chalcantha,
Chrysopogon serrulatus, AntJiepJiura pubescens, Digitaria eriantha
and Fingerhiithia africana.

11. — The V.^al Kameel Veld of the Asbestos ]\Iountaixs
{PJafcs XIV, XT').

The Vaal Kameel Veld of the Asbestos Mountains includes
the strip of country from the Asbestos Mountains and Kuruman
hills on the east to the Laugeberg and Kalahari in the west. The
Asbestos ^fountains, are low-lying and rounded hills which rise
about 1,000 ft. above the surrounding country. The surface soil
on the hills is reddish and is covered with small flat loose stones.
Along the foothills of the mountains there is frequently a belt of
deep I'ed sand. Between the Asbestos and Langeberg ranges the
soil is also mostly deep red sand, but in the northern j^ortion of
this area there is a small limestone plain similar to that on the
Kaap Plateau. This also lias numerous pans, and the veld closely
resembles that on the Kaap Plateau in composition and scenery.

The Asbestos hills are covered with scrub which varies in
height from 3 tO' 10 ft. The scrub is composed mainly of the
Ijstervarkbos (Lebeckia macracantha), the Vaalbos (Tarchon-
anthus camphoratus), the Zuurkaree {Rhus tridactyla), the
Olijvehout (Olea verrucosa), the Haakdoorn (Acacia detinens), the
Terassibos (Acacia stolonifera), the Blinkblaar wacht-een-bietje
{Zizyphus mncronata), the Klapper Bos (Xipnnnia capcnsis) and
the Driedoorn (Rhigozum trichotomnm and B. oJwvaiuiii).

Other common plants occurring on these hills are the Bitter
KarroO' (Clirysocoma tenuifolia), the Schaapbos (Pentzia incana),
the Wild Senna (Cassia obovata). tlie Vormc'erbo.''sie (Gcigeria
passerinoides), the Cape Slangkop (OniitJioglossiim glaucum), and
Sesamiini capense.

president's address. 23

The sandy beltsi along the foothills are, after rain, covered
with a luxuriant growth of grass, which is composed mainly of
Eragrostis lehmanniana, E. supcrba, Anthephora pubescens and
Aristida spp. Scattered through this sandy grass veld are
numerous trees of the Vaal Kameel thorn (Acacia haernatoxylou)
which range in height from 10 tO' 15 ft., and often give the veld
a dull glaucous grey appearance.

In the plains and valleys Karroo bush (Clirysoco)na tenuifolia
and Pentzia incana) and shrublets of Hai-puis (Euryops mulfifldus)
and Kapokbo'ssie (Eriocephalus pubescens) dominate the veld,
while scattered trees of Kameeldoom {Acacia Giraffae), Vaal
Kameel (A. hacmatoxylon), Haakdoorn {Acacia dctincns), Witgat
{Boscia albitrunca), Vaalbos {Tarchonanfhus camphoratus),
Blinkblaar wacht-een-bietje (ZizypJiiis mucronata), and Kriedoorn
{Lyciinn spp.) occur throughout.

Towards the north of the limestone plateau almost park-like
scenery is produced by bushes or t)'ees of the Olijvehout, the
Zuurkaree, the Haakdoorn and the Vaalbos. Grass is almost
entirely absent from the limestone plateau, where its place is
taken by Karroo bush. On the western edge of the plateau large
Witgat trees {Boscia albitrunca) form a conspicuous feature in the
veld.

The low-lying portions of the sandy veld between the Asbestos
Mountains and the Langeberg range are characterised by the
prevalence and abundance of bi'ak plants, while grass only occurs
on the well drained sandy slopes.

The vegetation on the Langeberg range differs from that of
the Asbestos, in that it is covered with bush or scrub from abont
6 to 10 ft. high, in which bushes of Croton gratissimum dominate.
Associated with this are bushes of RIius tridactyla, Grewia flavaf
and Tarchonanthus campJioratiis, in fact the Vaalbosch
(Tarchonanthus camphoratus) often dominates the vegetation on
the top of the range, while Croton gratissimus is dominant on the
mountain slopes.

A great variety of grasses occur on the Langeberg, chief
amongst which are: — Digitaria eriantha, Panicuni maximum,
Chloris petraea, Panicum nigropedatum , Sporobolus fimbriatxis,
Enneapogon tnollis, Pennisetum cencJiroidcs, Hctcropogori
contortus, Eragrostis gummifiua and Aristida spp.

12. — The Kalah.JiKi Sand Veld {Plate XVI).

North of the Orange Eiver and separating the South-West
Protectorate from the Union of South Africa is a large stretch
of sandy country lying at an altitude of 2,000 to 3,000 ft. It
includes the greater portion of the districts of Gordonia, Kuruman
and Vryburg. This area is the southern portion of the great
Kalahari region, and as it just falls within the scope of this
review, I shall refer to it as the Kalahari Sand Veld. It is
covered with deep sand throughout, which is in the greater part
of the area throavn up into long dunes which lie in a west-north-
west direction.

24 prksij^ext's addrkss.

Unlike the adjoining region of Bushmanland, the vegetation
here is much more pronounced and conspicuous ; instead of small
stunted shrubs, the Kalahari often supports a growth of well-
developed trees, amongst which the Camel Thorn dominates, and
under which a luxuriant growth of various grasses is usually
found.

The majority of the dunes are covered with coarse grass, —
the Pijpgras, — amongst which scattered " Witgat " trees {Boscia
rehmannlana, B. albitninca and B. Pcclniclii) are dotted about.
Some of the more common grasses in this veld are Eragrostis
superba, Eragrostis denudata, Eragrostis pallens, Aristida
uniplumis, Aristida. stipiformis, Aristida mollissinia, ScJiniidtia
bulbosa and Anthephora pubescens, while the low-lying sandy
plains with internal drainage support only a scanty growth of
brak plants, such as the Brak bos {Atriplex Halirnns), the Brak
Ganna [Salota aphylla), the Kapokbossie {Eriocephalus
miibeUatus) and tlie Harpuis bos {Euryops vinjtifidns).

The fact of the presence of numerous brak plants in this
region has an important bearing on Prof. Schwarz's Kalahari
scheme. Even if it were possible to irrigate the Kalahari, this
ground would be useless for agricultural purposes, as wheat and
similar crops will not grow in a brak soil.

One of the most characteristic plants of certain parts of this
sand veld is the Tsamma (Citrullus vulgaris), a melon which
furnishes a valuable stock food in times of drought.

13.— The Dam.\ralaxd Thorn Yeld {Plate XVII).

In the north-west corner of the inland plateau dealt with
within the scope of tliis address are situated the Highlands of
Central Damaraland, which consist of rugged mountainous
country with an average rainfall of 15 inches.

The vegetation is fairly uniform throughout and may be
described as the Damaraland Thorn Veld.

It is essentially a thorn scrub made up of bushes and trees
which range from 10 to 20 ft. in height and is composed of
Haakdoom (Acacia detinens), Acacia Maras, Acacia heteracantha,
A. dulcis, the Sikkelbos (Dichrostachys nutans), the VaalbO'S
(Tarchonanthus camphor atus), the Witgat (Boscia Pechuelii) and
Combretum apiculatuni.

Common succulents in this scrub, especially on the steep
hill slopes, are Aloe rubrolutca , A. hcreroensis and Senecio
longiflorus.

In the dry river valleys the trees attain a great size, and
consist chiefly of the Kameeldoom (Acacia Giraffac), the Doorn-
boom (A. karroo), the Blinkblaar-wacht-een-bietje (Zizyphus
niucronafa), Combretum primigenum and Acacia Jiebeclada. On
the open sandy flats the Stinkbosch (Boscia foetida), Kriedoorn
(Lyciu7n spp.) and Cataphractes Alexandri often dominate the
veld.

Towards the east the thorn scrub merges into tlie Kalnliari,
where the Haakdoorn becomes the dominant bush.

ri{KSI])ENT S ADDRESS. 40

14. — The Cameel Thorn Veld of Southern Damaraland
(Plate XVIII).

Occupying a comparatively small tract of country in Southern
Damaraland, a type of veld is found very different from that which
occurs in the adjoining region to- the south, in Great Namaqualand.

Instead of low xerophytic bush and scrub, a distinct park-like
or even forest type of scenery prevails. This type of veld.
coincides very closely with that part of the country which is
commonly known as Bastardland. It consists of deep sandy
flats well covered with high trees and grass. The dominant tree
is the Kameeldoorn (Acacia Giraffae), which is responsible for
giving the country the appearance of being densely wooded.
Other common thorn trees and bushes in this, veld are the
Doornboom (Acacia Karroo), the Haakdoom (Acacia dctincns),
the Terassi Bos (Acacia stolonifera), and Acacia hebeclada and the
Kriedoorn (Lyciitm sp.)

The grass is mainly Aristida ciliata and other species of the
same genus. On the southern outskirts of this Camel Thorn
Veld, where the soil is a little shallower, the veld is composed of
grass in which stunted Haakdoorn bushes and large Witgat
(Boscia albitrunca and B. Transvaalensis) trees are scattered
about.

15. — The Cape Veld ou South Western Veld (Phtic XIX).

Occupying a narrow angular strip of country in the extreme
south-west corner of the Capei Province is a type of veld unlike
that in any other part of South Africa. To botanist> the region
has long been known as the South Western Region of the Cape
Province. For the purposes of this address I shall refer to it as
'• The Cape Veld."

It is the best known botanically of all the types of veld in
South Africa, and has been very fully described by such able
botanists as Bolus and Marloth, so that it will not be necessary
for me tO' do more than describe in the briefest manner its most
salient features.

Its north-western arm extends as far as the Bokkeveld
Mountains, with outliers on the Kamiesberg, while its eastern
extension reaches to the Sundays Eiver Valley and includes the
forests of George and Knysna . On the north it is bounded by the
Karroo, although islands of typical Cape Veld occur in the Karroo
along the tops of the mountain ranges such as Zwartebergen,
Wittebergen, etc.

The country on the whole is very mountainous, the mountains
being rugged and bare.

On the mountain slopes, valleys and sandy flats, the veld is.
composed of stunted bushes and shrubs which range in height
from 3 to 6 ft. The dominant and most typical bush throughout
the region is the Rhenoster Bush (Ehjtropappus rhinocerotis). '

The average annual rainfall is about 29 inches, most of which
falls during the winter months.

Along the coast the common plants are SaJicornia friiticosa,
ChenoJea diffusa, Statice scabra. Grasses are very few in number,
the mo■^t typical are Stenotapininn gJabrum and Eragrostis

26 pr]:sii)kxt's address.

glabiata. Further inland on the sand dunes, common grasses
and sedges include Eragiostis cijperoides, Sporobolus pungens,
Agropyrum disticJinm and Scirpus nodosus. Common stunted
shrubs and bushes occupying the dunes are the Waxberry {Myrica
cordifoUa), the Dronkbossie [Cliymococca empetroides), the
Duinebossie {Mundtia spinosa) and the Kraaiebossie (Rhus
crenata).

Typical of the low bush or scrub on the sandy flats are the
Kersebos (Euclea raceniosa), the Schaapbostee (Psoralea
hracheata), the Suikerbossies (Protea ■mellifera and P.
scolymoccphala), tlie Kreupelhout {Leucospcrmnm conocarpmn),
the Blombos (Metalasia muricata), the Gouty Geranium
(Pelargonium gibbosum), the Bozemriet {Picstio eleochnris),
Carex arenaria, Eragrostis spinosa, Eragrostis cyperoides, and
Amniophila arundinacea.

In the inland valleysi and plains where the Ehenoster Bush
(Elytropappits rhinocerotis) dominates the veld, the Kapokbossie
{Erioccphalus umbcjlatus), the Herpuisbos (Euryops tennifi><imus),
the Doornbos (Metalasia muricata), the Slangbosi (Stoebe
cinerea), the Cape Sumach (Colpoon compressum) the Langeleden
(Polygala myrtifolia), and the Bosijzerhout (Dodonea TJiun-
bergiana) are alsO' frequent.

Typical plants occurring in vlei ground are the Palmiet
(Prionium serratum), the Varkblom (Zantedeschia aethiopica) and
the grass (Pennisetum viacrourum).

On the mountain slopes composing what is commonly referred
to as the Macehis, are the Silver trees {Lcucadcndro)i argcntcuni),
the Suikerbossies [Protea mellifera, P. lepidocarpodcndron and P.
neriifolia), the Olijvehout [Olea verrucosa), the Krentebos {Rhus
tomentosa), the J\Iirting (Myrsine africana), the Waaboom
(Protea grandiflora), the Kreupelhout (Lencospermnm
conocarpuvi), the Tolbo'^ {Lc{iicadendron plumosum), the Rooi
Stompie (Mimetes lyrigera), the Bakbos {Passerina filijormis),
the Wilde Malfa [Pelargonium cjiciiUatum) and Aspnlathus
chenopoda.

The forests of George, Knysna, and Humansdorp lie within
the So'Uth-Weistern or Cape Veld. They flank the Outeniqua. and
Zitzikamma Mountains and form a continuous' belt which is
roughly 100 miles long by 10 miles broad. The forests are
composed mainly of Black Stinkwood [Ocotea bullata), the
Yellow-woods {Podocarpus elongata and P. Thunbergii), the Rooi
Els (Cunonia capensis), the Black Ironwood (Olea laurifolia), the
Vlier (Nuxia fioribunda), the Assegaiwood (Curtisia faginca), the
Witte Els (PlatylophMs trifoliatus), the White Pear (Apodytes
dimidiata), the Kersehout (Pterocclasfrus variabilis), the Kamas-
sihout (Gonioma Kamassi) and tlic Coahvood (Tjachnostylis
capensis).

They are distinguished from the eastern forests by the
abundance of the Keurboom (Virgilia capoif^is), wliich is typical of
the South-Western Veld. The Zitzikamma forests are also
characterised by an abundance of the Stokroos {Sparmannia-
africana) which yields a valuable fibre.

PRESIDENT S ADDRESS. ^(

The remnants of a larger forest, which was apparently
Bimilar in composition to that of the Knysna, still exist on the
rocky slopes of the Langeberg near Swellendam.

On the west coast the ClanwilHam Cedars [Widdringionia
juniperoides) occur on the Cedar Berg Mountains. These
mountains also produce the well-known Buchu {Barosma
betulina) of commerce.

Among the poisonous plants in this region may be mentioned
Lessertia annularis, the Klimop {Cynanchum capense), the
Chinkerchee {Omitliogalion ili ijrsoidcs), various species of blue and
yellow tulps (Moraca and Hoincrla spp.),. and several introduced
plants. One of these, Datura stramonium, which has established
itself as a weed almost all over the country, is a valuable drug
plant.

Elytropappus rhinoccrotis is a very common and usurping
weed of the grazing veld, its inroads being largely due to
overstocking and burning the veld.

16.— The Kapjioo {Plates XX, XXI ).

The Karroo embraces the low-lying stretch of country which
lies immediately south of the southern portion of the Great
Escarpment.

The valleys of the Sundays Eiver in the east and the
Olifants Eiver on the west may be taken as approximately its
eastern and western limits. To the south it is intersected and
bounded by the Cape Ranges. It varies considerably in altitude
from 1,000 ft. in the central portion to 4,000 ft. above sea level
in the west.

The average annual rainfall also varies from under 5 inches
in the west to 15 inches in the central and eastern portions. In
the west the greater part of the rain falls during the winter
months, whereas the summer rainfall increases from the central
portion eastwards.

The Karroo is a country of shallow soils and rock-strewn
surfaces, consequently, when rain does occur, the ruu-nff is
extremely rapid.

The country is devoid of trees except along the dry river
courses, where a few t]iorn trees and kameelhooms usually occur.
Grass is also almost entirely absent.

The vegetation is largely composed of succulents, xerophytic
shrubs and shrublets.

The Karroo may be divided into four main regions: (1) The
Great Karroo or Central Karroo; (2) The Western or Ceres Karroo:
(3) The Little Karroo, and (4) The Eobertson Karroo.

The Great or Central Karroo includes the Ghoup,
Moordenaars Karroo, and the Eastern Karroo.

The vegetation in the Ghoup is composed mainly of small
bushes and shrublets, amongst which Rhigozuni obovafum usually
dominates, with it are commonly associated Lycium arenicolum ,
several species of Pelargoyiiuvi {P. munitum., P. carnosuyyt^ and
P. crithmifolium) and the Bushman's Candle (Sarcocaulon
Burmanni). The Karroo bush, Pentzia virgata, and the Kraal
Bosch (Galenia africana) are also often dominant over large areas.

^b PRESIDENT S ADDRESS.

In Moordenaars Karroo, shrubby Mesembrianthemums (M.
spinosum and related species) practically dominate the vegetation.

The Eastern Karroo^ is characterised by the presence of Aloe
ferox, Pentzia virgata, and an abundance of a number of succulent
species of Euphorbia, amongst which the Noorse {E. coerulescens)
is often the dominant plant, as in the Jansenvillet district and
Sundays Biver Valley.

Whenever the soil is inclined to be brackish, the Ganna bosch
{Salsola aphylla and S Zeyheri) takes possession of the veld.

The vegetation in the central portion of the Great Karroo' is
composed mainly of succulent Mesemhrianthemums which take
on a more or less cushion -like form of growth. These include
Mesemhrianthemum calamifornie, M. felhium, etc.

The Western or Ceres Karroo includes the Bokkeveld and
Tanqua Karroos, which are the driest parts of this region. The
Kraalbos (Galenia africana) and the Geel Melkbos {Euphorbia
-mauritanica) cover extensive areas and entirely dominate the veld.

The Little Karroo comprises the country surrounding
Ladismith and Oudtshoom. To the north it is bounded by the
JZwarte Berg range and on the south by the Lange Berg and
Outeniquas Mountains.

The vegetation in the Little Karroo is more pronounced and
more varied than the Great Karroo. It harbours a number of the
most interesting plants found m South Africa. In the western
portion, which includes the valley of the Touws River, one of the
distinguishing features of the veld is the presence of the Guarri
Bush (Euclea undulata) both on the plains and on the hill slopes.
Closely associated with the Guarri Veld are bushes and trees of
the Wilde Pruimen {Pappea capensis) and the Boer-boon (ScJiotia-
speciosa). In addition to this tree and bush growth the veld is
covered on the flats with an extensive growth of shrubby Vijge-
bossies (Mesernbrianthemum spp.), Gannabos (SaJsnIa aphylla),
Kraalbosch (Galenja africana), and Witbossie (Pteronia pallens).

On the hill slopes the vegetation is much more varied. The
most typical plant associations include the Botei'boom (Cotyledon
fascicular is), Plakkies (Crassula portulacea), the Geel Melkbos
(Euphorbia- mauritanica), the Rooi Alwijn (Aloe microstigma),
Crassula perfossa and Sarcocaulon spp.

The vegetation on the plains and valleys in the eastern portion
of the Little Karroo is of much the same type as that in the west,
but the Vijgebo'ssies (Mesembrianthemuyn spp.) more often than
not entirely dominate the veld, while the Bitter Alwiin (Aloe
ferox) and the Spekboom (Portulacaria afra) become more and
more prominent on the hill slopes towards the east.

Situated just beyond the south-west corner of the Little
Karroo is a small island of Karroo Veld commonly known as the
Boschjes Veld. This is now usually referred to as the Robertson
Karroo.

Its original name at once indicates the general nature of the
vegetation which is here more luxuriant than in other parts of the
Karroo. The bushes are composed chiefly of the Guarri (Euclea
undulata), the Bos-ijzerhout (Dodonaea Thunbergiana), the
Boer-boon (Schotia speciosa), and the Num-num iCarissa

peesiijent's address. 29

Arduina), while the succulents are represented by the Boterboom
{Cotyledon fascicularis), the Honde Oor {Cotyledon orbiculata),
the Plakldes {Crassula portulacea), the Geel Melkbos
{Euphorbia mauritanica}, and Vijgebossies {Mesembrianthemmn
blandiini and M. junceum).

On the more open ground ihe Kraalbos {Galenia africcuia)
and the Karroo-bossies {Pentzia incana and Chrysocoma
tenuijolia) dominate.

The northern part of the whole region is naturally invaded
here and there by typical Upper Karroo plants amongst which the
Doornvijgbos (Mesembrianthemum spinosuvt) is perhaps the most
prevalent; on the other hand, the southern borders of the Karroo-
are frequently encroached upon by plants from the Cape region,
especially is this the case with the hill-tops, which carry typical
Cape vegetation, while the hill slopes and high-lying plains are
frequently covered with the Ehenoster bush ' {Elytropappus
rhinocerotis).

17. — The Upper Karroo {Plate XXII).

In this region Kogers includes the south-west portion of the
Orange Free IState, the valley of the Vaal River south of Barkly
West and that part of the Cape Province between the Great
Escarpment on the south and Bushmanland and the Orange Eiver
on the north. Bolus adopted a very similar area for his Upper
Region. Marloth divided this area into a southern portion, the
Karroid Plateau, a north-west portion known as Bushmanland,
and a south-eastern portion, a part of the Bush Veld.

For purposes of a; plant survey, two' distinct areas can be
recognised; the southern portion, the Upper Karroo, the greater
part of which lies at an altitude of 4,000 to 5,000 feet, and which
is bounded on the north by the Langebergen, the Kubiskow
Range and the Karreebei'gen ; and a northern portion, which is
known as Bushmanland, which I prefer to include with the
Kokerboom Veld of Namaqualand.

The Upper Karroo is made up mostly of rocks of Karroo
sediments; it is a monotonous country, but broken with hills, and
the surface of the soil is covered with loose stones and bonlders.
The vegetation consists of short shrublets, not more than about
18 inches high, and these are chiefly Karroo Bush and shrubby
Mesembrianthem u ms.

18. — The Kokerboom Veld of Nam.\qualand and Bushmanland
{Plates XXIII— XXV).

Occupying the greater portion of the western edge of the
interior plateau is a large tract ol variable country which may be
described as " The Kokerboom Veld of Namaqualand," in which
the Kokerboom, Aloe dicJiotoma, is the most characteristic plant.

In the south it includes the rocky country in the neighbour-
hood of the Kamiesberg, the mountains of Ijittle Namaqualand.
the Richtersveld, the Valley of the Orange River as far east as
Prieeka, and practically the whole of Great Namaqualand north
of the Orange River, which lies between the Escarpment on the
west and the Kalahari region on the east. Apart from the

30 PRESIDKXT's A1)])RESS.

mountainous districts in the south-west corner, and the Valley of
the Orange liiver, the country is one of lable-landscapes and vast
plateaux and plains. Semi-desert conditions prevail throughout,
and with the exception of the Orange and part of its chief
tributary, the Great Fish Fdver, the river beds and water-courses
are dry throughout the greater part of the year.

The rainfall over practically the whole area is under 10 inches,
most of which falls during the winter mouths.

The region as a whole may be described as one of vast arid
and stony wastes.

The rocky mountains in the south-west corner of the region,
except for the presence of the Kokerboom and a few succulents,
are almost bare and destitute of vegetation.

The high plateaux to the east of the western escarpment are
covered with grass, which is mostly short, of a tufted habit, and
does not form a unifomi covering, but leaves bare spaces between
the individual plants. The chief grasses on these high plateaux
are Aristida dregeana, Aristrida obtusa, and Aristida subacaulis.

As companions to che grass are isolated bushes of Driedoorn
(Rhigozum trichotonvLtn) and a few succulents such as the
Bushman's Candle Saictcaulon Buniia^Dii) and Euphorbia
7iamibensis.

Further east, on the sandy plains, lying at the foothills of the
high plateaux, a rather different type of grass flora is frequently
met with. Here the plains are covered with the Toa Grass
{Aristida. brevifolia) which has a much more tufted or even bushy
habit.

The greater portion of the country to the east, which lies at
an elevation of 3,000 to 4,000 ft. above sea level and consists
mostly of vast undulating and stony plains, only broken here and
there by the presence of dolorite kopjes, is clothed with a scanty
covering of xerophytic shrubs, the chief of which are Parlcinsonia
africana, the Haakdoorn (Acacia detincus), the Nonnie Bosch
{Boscia foefida), Catapliractcs Alcxandii, the Driedoorn
(Rhigozum irichotonnnn), ZijgopJujllum }norgsana, Hermannia
spinosa, and the Ngaap {Houdia Gordoni).

The latter is one of the most characteristic succulents on the
flat sandy plains m Great Namaqualand.

Further east, where the plains of Great Xainaqualand merge
intO' the Kalahari region, and the area is one of internal drainage,
there are vast extensive flats, which only support a growth of
Ganna (Salsola aphijlla) bush, indicating tlie brackish nature of tlie
soil. In the low-lying valleys, which are below 3,000 ft. in
altitude, the Aggennys Euphorbia bush {E. gregaria) is nearly
always dominant, and is usually associated with bushes, shrubs,
and shrublets of Parkinsonia africana, Acacia detinens, Boscia
fortida, Cataphractcs Alcxandri. Bhigoznm tricliotoimim and
Pteronia glauca. Various species of Aristida grass also occur
here.

In the Orange Eiver Valley the character of vegetation is
more pronounced than elsewhere. Along the edge of the river
the dominant trees and shrubs are SaJix capensis, Zizyphus

riiKSIlJEXT's ADDRESS. 31

7nncronata, Euclca Fueudcbcnus, Comhretum erytJirophyllum,
Acacia karroo, A. Giraffae, Rhus viminalis, Royena pallens,
Tamarix articulata, and 'Sicotiana glauca, while Phragmites
co'inynunis is cornmon.

On the rocky slopes in the river valley, the Kokerboom (Aloe
dichotonia), the Gift-boom (Euphorbia virosa) and the peculiar
Pachy podium namaquanum occur.

In the gentle valleys leading to the river the Aggennys
Euphorbia is dominant, ar.d the Kraalbos (Galenia ajricana) is
very plentiful.

Along the dry river beds and valleys in the interior the vege-
tation is composed mainly of the Camel Thorn (Acacia giraffae),
the Sweet Thorn {Acacia A'orroo), the Black Ebony (Euclea pseu-
debenus), the Oliepitten (Pappea capensis), the Nonnie Bosch
(Boscia foetida), the Haakdoorn (Acacia detinens), the Tamarisk
(Tamarix articulata), Zygophyllum prismatocarputn, Z. simplex,
Z. viicrocarpum, Z. cylindrifolium, Lycium namaqucnse, Galenia
africana, and Salsola aphylla.

Physiographers usually regard Bushmanland and the Kalahari
as one region.

Bushmanland is one of the most arid parts of the inland
plateau, its annual rainfall is less than 5 inches, part of which
falls during the winter months, whereas the annual rainfall on
the Kalahari varies from 10 to 20 ins., most of which falls during
the summer months. In consequence there is a considerable
difference in the general aspect of the vegetation found in these
two areas, and for this reason they may well be treated separately.

Bushmanland is bounded on the west by the southern
■extension of the Namaqualand Highlands, which includes the
Kameesberg and the mountains of Little Namaqualand, on the
north by the valley of the Orange River, on the east by the Kaap
Plateau and Kaap Valley, and on the south by the Upper Region.

It is essentially a country of sandy plains, undulating and
featureless.

In the central jjorticni there are numerous salt-water pans,
while isolated rocky hills of the " Inselberg " type occur here and
there. The average height of the country varies from 2,000 to
3,500 ft., towards the north the surface slopes fairly uniformly
towards the Orange River. The vegetation throughout is sparse
and scanty, and consists mainly of shrubs and shrublets which do
not exceed 3 ft. in height.

After rain the Toa grass and Bushman grass are plentiful.

The dominant shrub on the red sandy plains is the Driedoorn
(Rhigoznm trichotomnm); with this are associated stunted bushes
of Parkinsonia africana, Hermannia pulchella, Hcrmnnnia
grandiflora, Cataphractes Alexandri, Boscia foetida, Cadaba
juncea, Zygophyllum spp., and Baiihinia garipensis.

Common succulents on the rocky outcrops, are Aloe
dichotorna ; and Sarcocaulon B^trmanni and Hoodia Gordoni on
the sandy plains.

The chief grasses are Aristida adsccnsionis Linn., ^4. vestita,
Thunb., .4. ciliata, A. namnqucvsis, A. obtusa Del., Erngrostis
^piiwsa Trin., and Enneapogon scabcr, Lehm.

32 pr];.si])ext's addkkss.

19. — The Western Littoral or Xamib (Plates XXVIXXVIII).

Ill striking contrast to the vegetation on the east coast, that
on the west is more scanty and desert like than any other part of
the sub-continent. This desert region may be described as the
\\'estern Littoral or Namib. It reaches from the Olifants Eiver
in the south to beyond the limits of our northern boundary. It is
a narrow coastal belt, varying in width from 10 to 80 miles, the
broadest stretch being from Luderitz Bay to' Conception Bay.
It is a barren wind-swept desert composed mainly of vast hills
of yellowish sand, and lies west of the western portion of the
Great Escai-pment. The rainfall is extremely scanty and varies
from to 5 inches per anmmi.

Some five distinct zones of vegetation may be distinguished,.
viz. : that of the western slopes ol the Escarpment, the Gravel
Plains, the Sandv Dunes, the ilocky Hills, and the Seashore.

On the rocky slopes of the Escarpment the Kokerboom
(Aloe dichotuma), Eupliorbia virosa, and E. drcgcana are most
conspicuous, whilst along the foo-thills clumps of Euphorbia
bracliiata are coinmon, and associated with them are plants of
the Bushman's Candle (Sarcocaulon Burmanni) and Pelargonium
crassicaule, Augea capcnsis, Mesembrianthemtim micranthuni,.
Galciiia africana, and Euphorbia namibensis.

Below this the vast gravel plains are for miles and miles
almost destitute of vegetation, or support a more or less scanty
growth of Vogelstruis grass [Eragro^fis spinofta). In some
places the only plant on these plains is an annual Mesembrian-
ihemum, on others nothing but a lichen growth covers the small
pebbles. Towards the north only a few isolated plants of Acrva
desertonnn occur over vast stretches, while Welwitschia mirabilis
is found in a few localities and is usually associated with
Zygopliijllum Stapfii.

The sand dunes support a very scanty vegetation, which is
made up chiefly of isolated tufts of Vogelstruis grass (Eragrostia
spinosa), Eragrostis cyperoides, the Ganna bush Salsola Zeylieri,
Statice scabra and Mesembriantheinum Marlotliii.

On the rocky hills fringing the seashore the vegetation is
more varied, and is composed of many extremely interesting
forms, such as Mesembrianthemuni opticvm^ Mcsembrianthonum
sa.refauum, M. rliopalophyUutn ^ Trichoraulon cacfifornuty
and Euphorbia Jignosa : other common plants are Ectadium
virgatum, Ercm.otliamnus Marlofhianus, Dicoma fomenfosa,
Pitiiranthus aphiillus, Augea capensis, and Lebeckia muUiflora.

On' tlie seashore three plants are fairly common, viz. :
Salsola zeyheri, CJienolea diffusa and Salicornia natalensis.

The river valleys which traverse the Namib carry a very
typical vegetation. In the upper reaches of the valleys, especially
in the north, considerable tree growth occurs, in the dry river
beds the characteristic trees are the Anaboom (Acacia albida), the
Camel Thorn (Acacia giraffae), the Omumborumbonga (Com-
hretiDu primigCHUhi), the Cape Ebony (Eiiclea pseudebenus), the
Tamarisk (Tamarix articulata) and the Choris (Salvadora persica).

The low-lying valleys are practically dominated by vast
stretches ol nothing but the Aggennys Euphorbia (E. grcgaria).

tresident's ai)])ress. 33

Neaier the coast, where several of the rivers disappear under
the sand dunes, their underground courses can frequently be
detected by the presence of the Naras (Acantlwstcyos hoirida)
and the Tamarisk {Tamarix articulata) amongst the dunes. The
Tamarisk has not received the attention which it deserves from
an economic standpoint. It grows splendidly in the sand dunes
and also' in saline and alkaline soils, while it yields valuable
timber and a plentiful supply of " galls " very rich in tannin; it
also' is very resistant tO' heat and drought. In North Africa the
small fruits are much esteemed by the natives for medicinal
purposes on account of the amount of turpentine which they
contain.

In view of the facts set forth in this brief and all too sketchy
and incomplete account of the veld, it is obvious that South
Africa is first and foremost a pastoral country, and as such her
stock-raising potentialities are mainly dependent on the veld. The
greater portion of the natural grazing land throughout South
Africa is subject to extremes of climate, periods of drought and
harsh treatment at the hands of man, but in spite of all this its
recuperative poweris are untold.

The most outstanding and convincing of the facts which are
brought to light by the preliminary survey of the veld is the
need for its closer study, which should include amongst other
things the careful mapping of the chief types of plants and their
associated soils. One of the aims of the Botanical Survey of
South Africa, recently established by the Government of the
Union, will be the recording and mapping of these plants, while
it is hoped that the mapping of soils will be undertaken by the
long advocated Soil Survey. It is both pleasing and encouraging
to note that provision has been made on the Estimates ol
Expenditure now before the House of Assembly for the salary of
a Director of the Soil Survey.

If progress is to be made in the solution of the problems
before us the closest co-operation must exist between the botanist
and the chemist. For this purpose, permanent stations for veld
research should be established in each of the different botanical
regions, and this the Botanical Survey hopes, in the course of
time, to do. In his preface to Memoir No'. 1 of the Botanical
Survey, the Secretary for Agriculture wisely remarks: " As time
proceeds and as soon as the foundations are securely laid, it is
hoped that whole-time officers will be appointed in the different
areas, who will at first work under the direction of their more
experienced colleagues, and will then later on become proficient
and render valuable service on the Survey."

The ]\Iemoir referred to above has been the subject of a most
favourable review in a recent number of the Kov Bulletin, in
which the concluding paragraph is as follows: "" The publication
of so useful a memoir by the Government of the Union of South
Africa affords welcome evidence of the enlightened view held by
that Government of the value of science, and also indicates that
they realise fully the need of acquiring an intimate knowledge
of the resources of the country by the development and proper
application of scientific method."

34 peesidext'.s ajjukkss.

No one has demonstrated more clearly what can be
accomplished by the co-operation of workers in different fields of
research than Sir Arnold Theiler, the Director of Veterinary
Eesearch, with whom it has been my privilege tO' be associated
in several of his investigations dealing with what he once termed
" the unsolved stock diseases of South Africa." The cause of
such diseases as Jacht-ziekte, Stijfziekte, Geeldikkop, Gouwziekte
and Bovine Staggers was only discovered after a close study of
the flora and veld conditions of the areas where these diseases
occur. So convinced is Sir Arnold of the importance of the study
of the veld in connection with obscure plant poisons that he has
now speciall,y attached to his staff a botanist whose whole time
is devoted to this purpose.

If the veterinarian can make such progress with the aid of
the botanist, there is no reason why similar results should not
be attained by the botanist and chemist in the many problems of
the veld that await them. To quote a specific case : it is well
known that stock fatten more rapidly in the Vaal Kameel Doom
Veld in the winter than in any other part O'f South Africa, and
that they may remain in good condition for a long time if removed
from that region to another part of the country, but no' one can
explain the reason. The cause is p?'obably to be found in some
close connection between the warm sandy soil of this veld and
the physiology' of nutrition, but who^ can say, withovit the most
careful enquiry? These problems can only be elucidated by tlie
trained botanist working continuously on the spot, and working
in co-operation with the chemist. The investigation of such
questions is of enormous importance from an economic standpoint,
and when such problems are scientifically and systematically
attacked the veld will yield a hurd red fold its present resourc^^
and its dangers wilF correspondingly decrease and diminish.

In conclusion, I wish to acknowledge my indebtedness to
INIiss Sydney Stent, of the Division of Botany, who supplied me
with notes on the economic plants of the various regions of which
she is making a special study.

S.A. JOUHNAL OF SCIKNCE, VOL. XVII.

Photo, by I. B. Pole Evans.

Fig. 1. — Ipomcea Pes Caproe, Sccevola lobelia, Osteospermum moniliferum,,
Strelitzia, augusta, Phoenix reclinata, TDvmorpliotlieca fruticosa.
Hibiscus tiliaceus, Oarissa grandiflora, Mimvsops cafjra, Ptferoxylon
utile, Millettia Siitherlandii. — Fort St. John's, Cape Province.

'/t*."™-" •. 1-L"" ..,?2 f-SiJii.'. WA

Photo, by I. B. Pole Evans.

Fig. 2. — (' yiiihdpoijoii iKirdiis raltilus in foreground, Acacia scrulj on hill
slopes, Pauwolfia natalensis lining stream below, forest on left
composed of Ptceroxlon utile, Millettia Sutherlandii, Harpc phyllum
caffrum, Ekebcrgia capensis, Ci/clostcmon aruutits, Trichilia
Dregeana. — Port St. John'S; Cape Province.

COAST VELD.

!S.A. .iOUHNAL OF 811K.NCK, VOI>. XVIi.

rj.ATK II.

PlioT^o. by I. B. Pole .'-avails.

Fig. 3. — Acacia pallens, Sijzijujum cordatum, Kifji'lia innnata, Tiich'dia
cnnficd. Ficii.s spp. — KlasstMie Rivei' Selati. Trans\aal.

fflP^.i^» rf

Photo, by I. B. Pole Evans.

Fig. 4. — Acacia pallens, Acacia xanthoploea, Viospyios mr.sjnliformis,
Hclcrocoriid caffra, Odina dificolor. Acacia. Benfliaiiii, I'ic'iniis
communis in foreground. — Near Komati Poort, Transvaal.

LOW VELD.

S.A. .lOUKXAL OF SCIENCE, VOL. XVII

PLATE 111.

Photo, by I. B. Pole Evans.

Fig. 5. — Knoppiesdoorn {Acacia palleris), with the Van "Wijk's Hout
{Bolusanthus speciosns) on the left, Rooigras {Themeda triandra)
in foreground. — Hectorspruit, Transvaal.

Fig. 6. — Mahogany (Afzdki quaiir:i'tisis). and Ah
Portngnese East Africa.

LOW VELD.

Photo, by 1. B. Pole Evans.
ic Mil rhdh It. — Xinavane,

S.A. .lori'.NAL OF SC 1|;N( K. VOI>. XVII

pff >.:^'

%• ^'^^'

Photo, by I. B. Pole Evans.

Fig. 7. — Beiikeiihout (Fdunn foViijixi). Suiker bos (I'mtid (iln/.-isinirii).
Karee {l{hus <i iK'inzii). Rooi Gras {TJirnieihi fruniilnt) in fore-
ground. — Near Zand River Poort. Transvaal.

vlt.< ■ * n

Photo, by I. B. Pole Evans.

Fig. 8. — Xymphd'O sfrlldtci, Aruiidi m Ihi Kcl:}iinil. Ti/jiIki ra iicii.six. — Zand
River Poort, Tranf^vaal.

^VATERBERG SANDVELD.

S.A. JOUKXAL OF SCIENCE. VOL. XVII.

Fi<

i). — Thcmt'iJa friatuJrn, And idiKx/oii (■ciis'id jormh
near AVakkerstroom.

Photo, by I. B. Pole Evans.
On tlie Draken.sberg

Photo, by I. B. Pole Evans.

Fig. 10. — EmijrDsf'ia jilana in foreground with Acnc'ia karroo, I'rofea
I>oui>iii'IH(r on the hill shi]3e. forest compo.sed of rndocnrpiis
falcata. 1'. flounntn. Ocofcn luillnfii. Xi/ninlos niomisjiord, Cilfh
kraussiatin. Giro lauriJoUa.

EASTERN GRASSVELD.

S.A. .lOl'HXAL OF SCIENCE, VOL. XVII.

PLATK VI.

Photo, by I. B. Pole Evans.
Fi^. 11. — ruiJdcdrpiix rhinijata with Oha Jaurifolia behind. — In Pirie Forest.
EASTERN GRASSVELD.

Photo, by I. B. Pole Evans.
Fi<i. 12. — HaiprplniHuin ((ifiiuin witli Ithii-s In r'tijafd behind. — Piric Forest.
EASTERN C4RASSVELD.

S.A. ,T0U1?XAL OF SCIENCE, VOL. XVII.

I'LATP: VII.

♦■*%-^''

Ph..t<

lj\ I. H l'..k- Kviui-.

Fig. 13. — Acacia caffirt. Acacia siiirocarpoidcs, D'ich ra.sfach i/s nutans, OJca
rcrnicoya. Sclcrocar\ia caffra, Acacia Jiailci, Vclfajihoonn
af rica n\nn. Schofia f la nsvaalrnsis, Boscia I'chnia n ni, with Kirl.ia
IT ;7;/i.s(( ill foreground. — Near C'huiiie's Poort, Transvaal.

<M^^

* WM'^Af' Si «'

Photo, by I. B. Pole Evans.
Fig. 14. — Eupliorhia ('oopcri. I'lofon Ouhoiii/a. — Olifant's River. Transvaal.

BUSHVELD.

S.A. .lOUli.VAL OF SC'lKNfK, VOf.. XVII.

1'lath: VIII.

i'h.jtu. by J. li. Pule Evans.

lo. — Wilde Soriiifr (lUiihid (ifr'u-(inii). Arnciti karroo, .1. roJnisto,
A. spirocarpotdes, Dichrostachys irufaiis. — Springbok Flats,
Transvaal.

''i%'4'l

Photo, by I. B. Pole Evans.

Fig. 16. — Acacia npirocarpohJcs. A. Bnithaini, Thcmalo friamlra. — Springbok
Flats, Transvaal.

BUSHVELD.

S.A. JOIHXAL OF SCIENCE, VOL. XVII.

Pho*o. by I. B. Pole Evans.

Fig. 17. — Acacia caffra, A. eriadenia, Cussonia paniculata, Zizyphus
mucronata. Miindulca suberosa, ^'angue^^ia infausfa, Bhus lancea,
B. Gueinzii, Euclea vndidatn, Pavefta obovata, Dombcya dcnsiflora,
Aloe Marlothii. — AVaterval Boven, Transvaal.

Photo, by I. B. Pole Evans.

Fig. IS. — Protea abyssinica, Combrctum zej/heri, C. Gueinzii, Acacia caffra,
A. harroo, Zizyphvs mucronata. Euclea undulata, Pavctta obovata,
I>. Gueinzii, Eiulva undulata, Paretta obovata, Dombeya dcnsiflora,
Aloe Marlothii. — "Waterval Boven, Transvaal.

BANKEN VELD.

S.A. .lOUHNAL OF SCIKM'E, VOL. XVIl

I'lioto. by 1. B. Pole Evans.

Fig. 19. — TJiiiiuihi ti'id 11,1 lit (luriii.u ^laifli. — Kaalfoiitein, ntai- Johannes-
burg, Transvaal.

Photo, by I. B. Pole Evans.

Fig. 20. — Thcmeda trlaiulrn in November. — Kaalfontein, near Johannesburg,
Transvaal.

HIGHVELD.

S.A. JOURNAL OF SCIENCE. VOL. XVII.

PLATE XI.

^'%s*»'**.^*i?*"

^pf'^'^'^iif^i,

«*»} "

Photo, by I. B. Pole Evans.
Fio;. 21. — Acacia f<pic<icariiohIi:s. A. <fnaff<t . — Near Kimherley. Cape Province.

Photo, by I. B. Pole Evans.

Fig. 22. — Acacia drthiciis, A. sjiiiora riioidcs. — Near ^yillflsorton Road, Cape
Province.

GR.IQUAT.AM) WEST THORXVELD.

S.A. JOURNAL OF SCIENCE, VOL. XVII.

PLATE XII.

-■■'M- \ ■

Photo, by I. B. Pole Evans.

Fig. 23. — Acacia detinens, A. spirocarpoidcs, Tarchoiiaiithiis camphoratus,
L'hi(jozuiii trichotonnini. — Near Douglas, Cape Province.

JS''*

It:

-• .»*-;1^«?

•fivff*t^.%^'v

§*■•
^

Photo by I. B. Pole Evans.

Fij:;. 24. — Olra rcrrucosa, Ithiis tr'nldcf i/hi. Vciifzia incann. — Near Postmas-
biirg, Cape Province.

KAAP PLATEAU BUSHVELD.

S.A. .TOURNAL OF SCIENCE, VOL. XVII.

I'LATE XIII.

Photo, by 1. B. Pole Evans.

Fig. 25. — Bhus vhninalis, Olea verrucosa, Tarclionantlius camphoraius,
Themcda triandra. — Near Papkiiil, Cape Province.

Photo, by I. B. 'Pole Evans.

Fig. 26. — Acacia detinens, Olca verrucosa, lilivs frrdacf\ihi, I'lnfzui inrana. —
Near Postmasburg, Cape Province.

KAAP PLATEAU BUSHVELD.

>S.A. .lOUKNAL OF SC'IKNCK, VOL. XVTI.

PLATK XIV.

'* ^

*\'

'K' ■* *

^1- :<

«! \

**'_

A V

>H.

Fip; 2;

. — LeJu'ckia macrdnflta, I'riifzi
Griquatow 11. Capo Pioviiict".

Photo, by I. B. Pole Evans.
hican'i. — Oil Asbestos Mountains,

Photo, by I. B. Pole Evans.

Fig. 2S. — Tarchonantliiis camplunatus, Fcntz'ia iiicana. — On Asljcstos Moun-
tains. Postmasburg, Cape Province.

VAAL KAMEELDOOEX VF.LD OF ASBESTOS MOUNTAINS.

S.A. .TOURNAL OF SCIENCE, VOL. XVII.

PLATE XV.

Photo, by I. B. Pole Evans.

Fi^. 20. — Vaal Kameeldoorn {Acacia haniafoxylon) with I'cufzhi incana
helow. — Floiadale, Capo ProvinCo.

b^\

^'S-'

'^V-i:^---,:!^ ".rir.ii

Photo, by I. B. Pole Evans.

Fig. 30. — ('rotoii (jrat'issiiiiuin. Acaiia (jiraffa', JBoscia tra nsraaleiish. —
Langeberg Range, Diininurry. Cape Province.

VAAL KAMEELDOORN VELD OF ASBESTOS MOUNTAINS.

S.A. .TOIHNAL OF SC'TKNCK. VOL. XVII.

I'LVTK XVI.

*V -

is£n£*

■'^r^V"*'*'^^^'^^'' '

S''f.;^5^:1'-;;

Pliolo. l)y 1. 'B. Pole Evans.

Fig. 31. — Acdcia drtiiirn-'i, Crnioii yKiti^.siiii ii m, X j/iiki nin capcnsis, Aiacin
tjiraffcc, Bo-tciu tin ns coal entiis. — Western slopes of the Laiigeherj^
Range, Dunmurry, Cape Province.

Photo, by I. B. Pole Evans.
Fig. 32. — Salsoln aiiliyJIa. — Near Tsumis. South-West Africa.
K.\LAHAR[ SAND VELD.

S.A. .lOUHXAL OF SCIENCE. VOL. XVII.

PLATE XVII.

-jfe**a£i'«su.-:^^

Photo, by 1. H. Pole Evans.

Fig. 33. — Acacia clctinfiis, A. Mams, A. hetcracanllia, A. <hiJcis, Cumin rtum>
apiculafuin, Dichrof>tachys nuiarts, Boscia rechuelln, Tarchonanthvs
camphnratiis, Aloe rubro-lutca, Euclca iiiuliilata. — ^Near Wiiidhuk,
Soutli-West Africa.

Photo, by I. B. Pole Evans.

Fiy. 34. — Acacia lichrara iiflia. .1. dtilcis. ( 'oinhri'tii in- a piculafuiii. Aluc
rubiu-tutea. — Noar Wiiulliuk, South-West Africa.

DAMARALAND THORN VELD.

S.A. .lOUKNAL OF SCIKNCK. VOL. XVII.

'LATK XVIII.

I'iKito. by I. B. Pole Kvaiis
Fig. So. — Akii in i/inifid-, ],j/(iiiiii sp. — Heiclt". South-West Africa.

■ \' :'

-^'•awfa

-.*!**

Photo, by I. B. Pole Evans.
Fig. 3(1 — Acdtia [I'lrdffd', Li/ciuin sp. — Heide. Soutb-West Africa.
KAMEELDOORX VELD OF SOUTHERN DAMARALAND.

S.A. JOUKXAL OF SCIENC'l',, VOL. XVII.

TLATK XIX.

I'hclo. h.\ I. IS. \',Ae K\ans.
Fiji;. 37. — L'('sfi(j association. — Sir fjowry's Pass. Cape Province.

Photo, by I. B. Pole Evans.

Fig. 38. — Hf'lirh rysuin rrsfttinn. El iff ■ nim innts rhinnrrmtis. — Tahle Mountain,
Cape Province.

CAPE VELD CR SOITH-WESTERX VELD.

S.\. .lOlKNAL OF SCIKNCR, VOI-. XVII.

PLATK XX.

?«^

' ..''^

^^►.

-^'* _

■p ~

Photo, by I. B. Pole Evans.
Fiji'. .39. — J'Jiiilcti u nd uhiid, I'dpiiia ca [iciisis. Schotid ludch mii'tdlid. Tf< mniti
ixilli'ii.s. — 'l'ou\vslior;j:. Cnpt' Province.

»-.

Fi^. 40. — ('(ifiilcddii fasciniJaris, ('. ]]'iilHc]i ii. Kiul
Lainfisbui'g, Cape Province.

KARROO.

Photo, by I. B. Pole Evans.

II lid' iildfd . — Near

S.A. .70UKXAL OF SCIENCE, VOL. XVII.

PLATE XXI.

*■' m'ijt^

Fig. 41. — Euclca inululata, I'trionin pdllcn;
Province.

Photc. by I. B. Pole Evans.
-Near Laingsburg, Cape

Ph >to. by I. B. Pole Evans.

Fig. 42. — Euclca undiiJata, Pterouia imllriis Mesoiihiia iifliini ii m spp. — Near
Laingsburg, Cape Province.

KARROO.

S.A. .lOrUNAL OK SCIKNCK, VOI,. XVII.

I'LATK XXII.

I'lioto. by I. H. l'i)le Kvaiis.

Fi^'. 43. — Mcsriiiliiiii nflii III II III s|)]).. (liiJi' ii'iii iif I'ini All. — Ni^ar Sutherland.
Cape Pioviuce.

Photo, by J. B. Pole Kvans

Fi^- 44. — AifJi ni.solr II iiiil ijsi' jiliiihi s. !■! n ii ra ii<i</rii scoiiarius^ Kniii rusl is f run
ciitii. K. ithtusd. — Near Luckhoft'. Orange Free State.

UPI'ER KARROO.

S.A. JOrUNAL OF SCIENCK. VOL. XVII.

PLATK XXIII.

t j'^ *^«ft^»* j(^

1!0>»-''

i«li

Photo, by J. B. Pole Kvan^.
Fig. 45. — Itliigozum trichotominn. — Bushmanlaiid.

Photo, by I. B. Pole Evaus.
Fig. 46. — Aloe (licliofojna. — South-West Africa.
KOKERBOOM VELD OF NAMAQUALAND AND BUSHMANLAND.

S.A. .lOrUNM. OF SCIKM K, VOI,. XVIT.

IM.ATK XXIV.

^ . . •.-:

,»..,

iitfe

'''.'. k3^"-'

•--■?„

Phot 3 by I. B. Pole Evans.

Fiji. 47. — AJiic <ri(litifiiiii<i. Kii I'iiiiiliKi rtinsd, K. iircijarid. JJ . dicliotoiiifi . —
Betwi'on H(j)oo<!: and Klein Karas. Soiitli-West Africa.

%^*" ' .»

Photo, by I. B. Pole Evans
Fig. 4S. — ratk'nisonia afiicana, Zygophyllum spp.
KOKERBOOM VELD OF iNAMAQUALAND AND BUSHMANLAxND.

S.A. .lOURNAL OF SCIRXCE, VOL. XVIT.

PLATK XXV.

2^^j#«i%«^3

Photo, by 1. B. Pole Evans.

Fig. 49. — Aristida drcgcana, .1. obtusa, A. siibocauJis. — Near Aus, South-
West Africa.

Photo, by 1. H. I'obs l■^an^-
I'^io;. oO. — Arisfiihi hrcrifiJ'Ki . — Near Kuiliis, Soiith-West Afi-ica.
KOKERBOOM VELD OF NAMAQUALAND AND BUSHMANLAND.

S.A. .lOUr.NAL OF SClKNCi:. VOL. XVIl.

PLATE XXVI.

■«i4^

^*aii..

-miM'

Photo, by I. B. Polo Evans.
Fig. ol. — jl'JiijJitirbid ijrr(/(u-i(i . — Xt'ar Aukas, Soiitli-Wcst Africa.

#■_ «

Photo, by I. B. Pole Evans
Fig. 52. — L'ti/i/iarOia i/rri/nriii . — Near Auka.s, South-West Africa.
THE NAMIB.

S.A. .lOUIiNAIi OY St'IUNCl';, VOF,. XVU.

I'LAl'K XXVII.

Photo, by 1. B. Pole Evans.
Fig. 53. — Eraijruxtis sp'tnusa. — Near Garub, South-West Africa.

Photo, by I. B. Pole Evans.

Fig. 54. — ^Erru ch<trtui uiii, A<urlu ■<tolun'if\i-a. — Neax' Kossing, Soutii-West
Africa.

THE NAMIB.

S.A. .TOFKXAL OF St'lEXC'R, VOL. XVII.

TLATR XXVIir.

Photo, by I. B. Pole Evans.
Fig. 55. — Acanthosicyos horrida. — Walfish Bay.

Fig. 56. — Tnmnr'ix a iiif\tJnta.
THE NAMIB.

Photo, by I. B. Poli' Evan
-Walfisli Bay.

rKKSIIlENTIAL ADDRESS SECTION A. 35

EECEXT PRUGEESS IN ASTROXOMY.

By H. E. Wood, M.Sc, F.R.A.S., F.R.Met.S.

Union Ohservatorjj, Jolianneshur-fi .

Presidential Address to Section A, delivered Juhj 14, 1920.

I should like to commence my address by referring to
tlie fact that the present year marks a definite epoch in
the history of astronomy in South Africa. It is exactly
one hmidred years ago since the foundation of the Royal
Observatory at the Cape of Good Hope. The Commissioners
appointed by Act of Parliament " for more effectually
discovering the longitude at sea " first discussed the question
of the establishment of an Observatory at the Cape on
February 3, 1820. There was then no jiermanent astronomical
Observatory at the Cape, although the Abbe Lacaille had
spent two years at Capetown (1751-1753) and had made a
catalogue of southern stars. A bronze tablet erected by the
South African Philosophical Society — now the Royal Society
of South Africa — marks the site of Lacaille 's Observatory
in Strand Street.

On October 20, 1820, by an Order of His Supreme Majesty
in Council, the Royal Observatory at the Cape was definitely
established, and the first of His Majesty's Astronomers at
the Cape — the Rev. Fearon Fallows — was appointed on
October 26, 1820. There was considerable delay in erecting
the necessary buildings, and it was not until the beg'inning'
of 1829 that the Royal Observatory was an accomplished
fact. Since its inception the aim of this institution has been
constant — to be the standard Observatory of the Southern
Hemisphere, and to be for that hemisphere what Greenwich
Observatory is for the Northern Hemisphere.

The state of South Africa one hundred years ago was
very different from its state at the present time ; equally so
is there a very wide diff'erence between the state of astronomy
then and now. The distance of not a single star was known
then, and it stands to the credit of the second of His Majesty's
Astronomers at the Cape, Thomas Henderson, that he was
the first to measure successfully the distance of a star — the
star Alpha Centauri — although, partly on account of the
remoteness of the Cape from Europe in those days, he was
not the first to publish the distance of a star, being slightly
anticipated by the European astronomers Bessel and Struve.
At the present time the distances of many stars are known.
It was the chief work of Sir David Gill to measure the
distance of the Sun, which is the unit distance to which the
distances of the stars are referred, and also to measure
the distances of the brighter southern stars.

The great practical problem of astronomy is the measure-
ment of the distance of the stars. A knowledge of stellar
distances is required in all investigations into the structure

3G PEESIDEXTIAL ADDEESS SECTIOX A.

of the IJniverse. Early attempts to measure the distance
of a star, althoiig-h not successful in their actual object, led
to far-reaching discoveries. Bradley, in 1725, in atteniptino-
to find the distance of the star Gamma Draconis, discovered
aberration and nutation. Herschel discovered the existence
of binary stars, and, on investigating the apparent changes
in the positions of a few stars from tliose given in early star
catalogues, discovered the motion of the Sun, and made a
fortunate guess as to its direction of motion and velocity.
Ilis first determination depended upon the observations of
only seven stars, but does not differ very widely from tho
results of recent investigations, in which the ap])arent motions
of thousands of stars have been discussed. The application
of the spectroscope has confirmed the result, and has added
a direct determination of the solar velocity. Stars in a certain
direction in the sky appeared to be moving towards the Sun ;
others in the antipodes of the sky apj^eared to be receding
from us with the same velocity. This velocity has been deter-
mined to be 195 kilometres per second. It was soon realised
that one result of the Sun's motion through space was to
afford a new method of determining stellar distances applic-
able to distances so great that the ordinary direct method
failed. In one year the Sun, and with it the whole of tliQ
solar system, moves through space over a distance equal to
four times the distance between the Sun and the Earth, or
372 million miles. In ten years the distance moved is
forty times the Sun's distance, and the distance increases
directly with the time. Thus an indefinitely increasing base
line is obtained, whereas in the direct method of determining
a stellar parallax the base line cannot exceed 18G million
miles, or two units. If, then, an exact comparison can be
made between the relative positions of the stars at the present
time and their relative positions many years ago, there must
be certain differences due to the change in the point of view.
The nearer stars lying in directions at right angles to the
direction of the Sun's motion must be displaced with reference
to more distant stars in the same direction, and generally
the stars would appear to diverge from the apex of the Sun's
way and to converge towards the solar antajjex. If, now,
the stars were all at rest, it would be a very simple matter
to measure the distances of thousands and thousands of stars
by their displacements relatively to more distant stars, and
the number of stars whose distances could be measured and
the accuracy of the results obtained would increase as the
time increased. But analogy suggests that it is hardly likely
that our Sun alone is in motion and all the rest of the stars
are fixed in space, and investigation has proved that prac-
tically all the stars are in motion. If these motions were all
at random, it would still be possible to determine the
distances of groups of stars, for the random motions taken
over the group would neutralise one another, and the group
as a whole would be at rest. In this way Kapteijn, amongst
others, has statistically determined the distances of various
groups of stars. It had been suggested by Kobold, and later

PRKSI])ENTIAL ADDRESS— SECTION A. 37

became evident to Kapteiju in 1904, that the motions of the
stars conkl not be considered to be entirely at random, and
at the joint meeting of the British Association for the
Advancement of Science and the South African Association
for the Advancement of Science at Capetown in 1905, Kapteijn
announced tliat there Avere two preferential directions of
motion amongst the stars.. This statement can be explained
in a variety of ways. If the motions of the stars could be
plotted on a three-dimensional diagram, with vectors repre-
senting the velocity and direction of motion of each star,
the resultant surface would be an ellipsoid with one relatively
long axis. This long axis of the ellipsoid would represent
Kapteijn's preferential directions. More simply, it might be
considered that there are two directly opposed streams of
stars, which was the view taken by Kapteijn, who called
the two streams Drift I and Drift II. Drift I is directed
towards 90°, -12°, and Drift II towards 270°, -55°. These
directions are affected by the motion of our point of
observation — the Sun — and, if tliev are corrected for this,
the directions are found to be 94°^ +12°, and 274°, -12°,
opposite to one another and in the plane of the Galaxy — which
is a fact full of significance.

This discovery of systematic motions amongst the stars
has greatly complicated the question of determining stellar
parallaxes from proper motions, but has carried us much
further in investigations into the structure of the Universe.

The investigation of systematic motions amongst the
stars has occupied us at the Union Observatory for the past
three years, and the portion of work we have undertaken
is by no means completed yet. Ordinarily the process of
determining proper motions is a very slow one. Meridian
observations of star places are made at an Observatory and
published as a star catalogue for a certain ei^och. The work
is rejieated at the same or another Observatory at a later
date and a catalogue published for a later epoch. By bringing
the places of the stars to a common epoch, the difference
between the two places for the same star, after all possible
sources of error have been eliminated, is due to the propei^
motion of the star. This is a slow and tedious process, and
it is never advisable to determine a small quantity as a
difference between much greater quantities. Further, and
this is very important, only those stars are dealt with which
are bright enough to be observed Avitli meridian ii\struments.
The results would thus be incomplete, and only refer to the
brighter stars.

It is a dift'erent matter when star photographs are dealt
with. Suppose that two photographs have been taken Avith
the same telescope of the same region of the sky, and Avith
an interval of some years between them. These tAvo photo-
graphs can be optically superposed and minutely compared
AA'ith one another. If there were any motion common to all
the stars of the region, this could not be detected, because
the superposition of the tAvo plates would automatically
eliminate this. Such a common motion could be determined

I'KKSIJJKXTIAL A])])RK.SS SKCTIOX A.

only by reference to the meridian catalogue positions of
whatever stars there Arere on the plates Avliose position had
been determined by meridian telescopes at different epochs.
The detailed investig-ation of the jDlates is carried on at the
Union Observatory with the helj) of a stereo-comjDarator and
blink-microscope. This is a wonderful instrument, Avhich
enables corresponding i:»ortions of the two jslates to be com-
pared in rapid succession, and shows at a glance relative
disj^lacements amongst the stars of a small region. The same
result would be obtained, but with an enormous expense of
time and labour, by measuring the co-ordinates of each star
image on the two plates and comi^aring the measures for the
corresponding stars. Discrejjancies here would also show
relative displacements amongst the stars on the plate. But
whereas in this method every star must be measured to find
the few showing motion, the blink-microscope selects just
those few and practically ignores the rest, with the resiilt
that not only is the labour very much less, but also the
liability of error. In actual practice, something like one in
a hundred stars will show a small displacement with reference
to its immediate surroundings. It remains to inteiiDret
actually what this displacement means. Theoretically, if the
majority of the stars on the plate are at an infinite distance,
so that it can be assumed that their relative configuration
remains unaltered as seen from the extremities of a base line
as long as that over which the Sun would move in twenty-five
j-ears, i.e., 100 units (assuming twenty-five years to be the
interval of time between the taking of the two photographs),
then the displacement seen for any one star would indicate
its shift against the infinitely distant background. This shift
would be due to either or both of two causes — (1) the change
of viewpoint, i.e., the motion of the Sun, or (2) actual motion
in a fairly near star. Thus from either point of view the
blink-microscope would pick out the nearer members of the
stellar universe.

A larg-e number of plates taken with astrographic
telescopes for the purposes of the Carte-du-Ciel has been
examined at the Union Observatory with the blink-microscope.
Mr. Innes has examined pairs of plates of the Greenwich,
Melbourne and Sydney Zones, and, with myself, is examining
the whole of the' Cape Astrographic Zone. I have re-photo-
graphed practically the whole of the Cape Zone to secure new
plates to compare with those taken originally. The time
interval between the members of each pair of plates is about
one-quarter of a century. The work of examining the plates
is not yet completed, and there is the further great task of
analysing the results to be done. Already it is evident from
a preliminary survey of the portion of the work done that the
moving stars so picked out by the blink-microscope divide
themselves into two main classes. These are Kapteijn's
Drifts I and II, and the directions of motions of these
groups coincide fairly nearly with the directions predicted
from the generallv accepted positions of the apices of the
drifts. Further, the division into two classes is so sharp and

PRKSIJJKXriAL A])J>KKSS SKCTIOX A. 39

pronounced as to .suo<)'est that we are not dealino- with a
distribntion of steUar motions in one system such that the
veh^city surface is aji ellipsoid with one relatively long- axis,
but that we are actually dealing with two definite streams of
stars. The suggestion is made here tentatively, for further
work has to be done, that the results obtained support the
view that in the near vicinity of the Sun we have two star
clusters intermingling and passing through one another.
Further, the comparison between the blink-microscope
motions for bright stars, bright enough to figure in meridian
catalogues, with the catalogue results for the motion shows
the hypothesis that the background of stars is at a relatively
great distance to be fairly correct.

Much new work has been done recently in the deter-
mination of stellar parallaxes by indirect methods. These
indirect methods all depend upon the simple principle that
if you know the absolute magnitude of a star you can
determine its distance from us from an observation of its
apparent magnitude. If the lights of a town are seen from
a distant elevated point, the more distant street lamps
appear to be much fainter than the nearer ones, and, if it
is known that the same type of street lamp is in use
throughout the town, the distance of the far relatively to the
near ones can be deduced from the apparent brightness of
the two. If the distance of the near lamps is known, the
actual distance of the more distant lamps can be calcidated.
Hence, if a number of stars of the same absolute magnitude
can be recognised in the sky, the more distant ones will have
a relatively greater (fainter) magnitude than the near ones.
If the distance of the near ones has been determined by the
direct method of determining stellar parallaxes, then the
actual distances of the fainter and more distant ones can be
deduced from the relation between the apparent magnitudes.

There are various ways in which the absolute magnitude
of a star can be estimated. Adams and Kohlschutter, in
1917, detected differences in the relative intensity of certain
lines in stellar spectra depending upon the absolute magnitude
of the star. Consequently, by comparing spectra of stars
of the same type they can deduce the absolute magnitude of
the star, and then from its apparent magnitude its distance.
This is a wonderful extension of the work of the spectroscope,
which was used primarily to find the chemical constituticni
of a star, then its velocity, and now its distance.

There is a certain class of stars designated the helium
stars. There are many reasons for considering that such
stars are at the zenith of stellar evolution and are the hottest
stars. They are the most massive of the stars, and, further,
they all have approximately the same mass. Hence, if a
star is found by the spectroscope to be a helium star, its
distance can at once be deduced from its apparent brightness.
Thus the onlv limit to determining the distance of a helium
star is that ' imposed by the spectroscope — there must be
enough light to show the character of its spectrum.

40 PRESI1)E>-TIAL ADDRESS SECTION A,

By investigating all the known scattered helium stars,
Charlier finds that they form a bun-.shaped cluster haying-
dimensions of the order of 0,000 light years Ly 2,000 light
years, and that our Sun is about 500 light years aAvay from
the centre of this system. Helium stars are also shown by
the spectroscope to have very small velocities or to be nearly
stationary in space, so that when a displacement is found
for a helium star, this must be chiefly the reflex of the solar
motion, and so the distance of the star can be deduced from
this displacement.

It has been found possible with modern instruments of
exceedingly powerful light grasp to detect the presence of
helium stars in globular clusters. This enables the distance
and dimensions of the cluster to be at once deduced, on the
assumi:)tion that all helium stars are of the same (uder of
absolute magnitude. The conclusion is arrived at that such
a cluster as the Hercules cluster is no less than 100,000 light
years away, and is really a stellar system almost approaching
in dimensions to those attributed to the Milky Way. These
tremendous figures must be accepted Avith reserve until it
has been conclusively proved that the stars of these compact
clusters differ in no respects from non-cluster stars. The
chief use of such powerful instruments as the new 100-inch
reflector of the Mount AVilson Observatory will be to
investigate the spectra of the stars in such clusters, with a
view to increasing oiir knowledge of these very distant
sj'stems.

Much has been learnt from the study of the behavioui;
of variable stars. One particular class of variable star— -the
Cepheid variable — has recently attracted much attention.
It is now considered by many astronomers that the Cepheid
variable — in which the*^ rise to greatest light is fairly rapid
imd the fall more leisurely — is due to the pulsations of a
gaseous star obeying the Unvs of a perfect gas. From this
it has been deduced that the period of vibration of the mass
of gas varies directly as the density, and hence iipon the
absolute magnitude of the star. Many such variables have
been found in the smaller Magellanic Cloud, and have led
io an estimate of the distance of this sys-fem, viz.. (iO, 000 light
years. The law connecting the period of variation with the
absolute magnitude has been tested for all known Cepheid
variables, and has been found to be consistently true. Hence
the determination of the distance of a Cepheid variable is a
simple deduction from its period of variati(m and its apparent
mean magnitude. . .

One fruitful result of the spectroscopic examination of
stars, combined with an investigation into their absolute
mao>nitudes, has led to the discovery of two types of stars—
the oiants and the dwarfs— and has considerably inodihed
our Tdeas as to the order of stellar evolution. Briefly, the
stars can be divided into six principal spectral classes
{omitting some minor classes), viz., helium stars^ hydrogen
stars, calcium stars, solar stars, and stars with fluted spectra.
These are referred to as B-, A-, Y-, (i-, Iv- and M-type stars.

pr]-:sij:)F.>tial a])Dress — spxtiox a. 41

and the order of evolution was supposed to be in the direction
from the B-type stars to the M-type stars, although
Sir Norman Lockyer always maintained that there must be
stars of ascending- temperature as well as stars of descending-
temperature. The discovery of giant and dwarf stars supports
Sir jSiorman Lockyer's view, and gives us more explicit ideas^
of stellar evolution. A large mass of gas in an extremely
diffuse state may be a giant M, or red, star. Obeying the
laws of a perfect gas, it will shrink or increase in density
and rise in temperature, passing through the spectral classes
K, Q, F, A to the helium stage B when it has its maximum
temperature. Throughout this part of its history its absolute
magnitude remains the same, its diminishing surface area
balancing the increased emissivity due to higher temperatures.
At the helium stage the star's density has become so great
that the perfect gas law is no longer obeyed. The loss of
heat by radiation is now greater than that generated within
the star, which nov/ commences to fall in temperatvire. The
star now passes down the spectral scale in the order
A, F, G, X, and becomes once more a M-type star, but
now its density is great, i.e., it is a dwarf star. Thus, when
the M-type stars are classified according to absolute
magnitude, they fall into two distinct groups, with a con-
siderable difference of absolute magnitude between them.
There will be similar groups for the K, Gr, F and A classes,
with decreasing differences of magnitude between the classes,
but there w411 be only one class of B-type star. Not all stars
can reach the helium class — they are not sufficiently large
enough to develop the necessary high temperature. Our Sun,
comparatively a small star, is thought not to have risen above
the F-, or calcium-, type. The helium stars are considered
to be the largest of all stars, and to be probably all of,
roughly, the same size, of the order of about one thousand
times the Sun's mass. Professor Eddington has recently
studied the condition of stellar existence as a consequence
of the laws of perfect gases, and concludes that there is aj
definite limit to the mass of a star, bevond which it could
not exist as an entity. This limit is probably represented by
the helium-type stars.

There is an important relationship between spectral-type
and stellar radial velocity, the sig-nificance of which is not
yet thoroughly understood. Each spectral class has a certain
velocity, Avliich diminishes from the M-type to the B-type,
the slowly-moving helium stars. By some it is considered
that this represents equipartition of energy amongst the
stars, i.e., for all the stars the product of the mass and the
square of the velocity is constant, so that the massive B stars
have low velocity and the less massive M-stars greater
velocities. Considering the comparative emptiness of space
and the enormous distances between stars, it is very difficult
to see how equipartition of energy has come about. Such
a view would compare the distribution of stars in the
Universe and their movements Avith the motions of molecules
in a gas.

TRESIDEXTIAL ADDRESS SECTIOX A.

The enormous distances deduced for the globular clusters
IS very much exceeded by those found for the spiral nebula?
by these indirect methods. The spectroscope has shown that
the spiral nebulae have radial velocities very much greater
than those of the stars. This fact, combined with the absence
of any detectable cross or proper motion indicates their
distance to be very much greater than the stars. The
discovery of novae or new stars within certain of these
nebulae confirms this idea, and has led to estimates of their
distance. The theory is, that whatever celestial catastrophe
it is which gives rise to the outburst of a new star, the order
of magnitude is the same, whether the occurrence takes place
within a spiral nebula or within our own Milky Way. Hence,
from the apparent brightness of the new star in the nebula,
its distance can be estimated in terms of the distance of the
Milky Way.

Such ideas as these concerning- the existence of huge
stellar systems at inconceivably great distances, or " island
universes," are only tentatively accepted by astronomers.
They represent logical deductions from observed facts, but
the facts are still very meagre. Also, they involve extra-
polations from physical laws based upon experience of the
behaviour of matter under the conditions existing on this
Earth, and the curve of our experience may in its remoter
branches take some unforeseen direction. For instance,
certain facts connected with the Great Nebula in Orion can
only be explained by supposing that the mass of gas which
constitutes the nebula must have a density less than
one-millionth of that of ordinary air at sea-level, and yet in
some way or other this gas is incandescent. It must be
admitted that our knoAvledge of matter in this state is very
meagre.

Thus these ideas can only be accepted with caution until
the convergence of different lines of research approaching
from different directions and the steady accumulation of
unassailable facts puts them on a firmer foundation. If they
are wrong, they will fall to the groimd, but even a false
hypothesis has served a useful purpose in indicating methods
of research. In this region of astronomy the astronomer
waits somewhat upon the physicist and chemist to inform
him of the behaviour of matter under very varied conditions
of pressure and temperature.

PRKSIDKXTIAf. ADDRESS SKCTIOX ]?. 43

GEOLOGY IX RI]LATI()X TO MIXIXG.

By F. P. Mkxxell, F.G.S., M.I.]^r.M.

F residential Address to Section B, delirered Jul;) 15, 1920.

The original occupation of most of Scnitli Africa,
llliodesia excepted, lias been dne to the pioneer efforts of
the farmer, or, more correctly, the pastoralist, rather than
the miner. It cannot, however, be gainsaid that there is no
country which owes its material advancement in greater
degree to its mining- industry. It is difficult to picture what
Sovith Africa would be like without its gold and diamond
mines and the cities which their wealth has called into being.
There may, of course, be some controversy as to whether
pastoral simplicity woidd not have resulted in more ideal
conditions from the point of view of those economists who
follow Ruskin in declining- to regard the income alike of
the country and of the individual as the best test of real
progress.

We are not, however, concerned to-day, except indirectly,
with the economic or sociological aspects of this question.
AVe have met together as students of physical science, and
we have to consider the application of the science that we
profess to the problems which confront us, which have arisen
throug-li conditions that must be reckoned with whether or
no they have our concurrence or our approval.

Personally, though I missed the first pioneer activitj' —
the most interesting- period of all — it has been my privilege
to follow all the later developments of the country in whose
chief town we are holding our Annual Congress. At the time
of my arrival I do not think a single dividend had been
declared by a Rhodesian company, so that I have seen most
of the work of placing the mining- industry on a sound basis.
In some of the developments which have taken place I have
had an actual share, and in all of them I have taken a close-
interest, quite apart from the merely material considerations
involved. My province has, in fact, been that of the geologist
rather than the mining engineer, and it is from the geological
standpoint that I intend to discuss some of the problems
AA-hich confront, not only this country, but South Africa as
a whole at the present day.

All thoughtful people will, I think, admit that we are in
the throes of a great industrial revolution. I do not refer to
the position of labour, but to the larger problems of industrial
readjustment which now confront all civilised nations. The
conception of England as the workshop of the world, on
which Cobden largely based his successful Free Trade cam-
paign, can now be seen in its true perspective as constituting
a mere passing phase. The great war has undoubtedly done

44 PRESIDENTIAL ADDRESS SECTION B.

much to lielp on the realisation of this fact, but, even without
the war, its recognition was none the less inevitable, in spite
of the obstinate refusal of a large school of English economists
to face the situation. At the time when the Corn Laws
were repealed, England was believed to possess unassailable
supremacy in her iron and steel industry, so much so as to
be able to base other industries, such as the production of
cotton and woollen goods, upon that supremacy, combined
with her unrivalled position as a producer of coal. Yet it is
already thirty years since the United States wrested from
Britain the premier position in the iron industry. To-day
the American production is three times that of the Home
Country, and Germany, which passed ahead of Great Britain
in 1903, had even before the war increased the yield of its
furnaces to nearly double that of the British ironworks. We
have recently witnessed the successful establishment of blast
furnaces in Canada, in Australia, in India, and still more
recently in South Africa itself, where three separate concerns
are now in operation. It is easy to see that the day cannot
be far distant when the Empire will be self-supporting in the
iron and steel industry, except as regards certain special
departments, wherein the inherited skill and hard-won
experience of the British ironmaster and his workmen will
enable them to maintain their position for another generation
at least.

Our modern civilisation, it has been claimed, has as its
basis the successful utilisation of mineral products, and
especially of metals. I have cited the iron industry partly
for this reason, and partly because it was for so long regarded
as peculiarly British. It is clear, too, that if the newer
nations of the Empire become independent in that direction,
they will easily develop in others. It must also be remembered
that what has been said of Britain is applicable in large
measure to the rest of Europe. Some twelve years ago I
pointed out in my book, " The Miners' Guide," how imperfect
was the adjustment of the mining industry to modern con-
ditions. The centres of production often had then, and still
have in great degree, no relation whatever to the principal
sources of supply of several important metals. The aluminium
ores of France even now go across to America for treatment,
and those of British Guiana are going to Canada, while the
manganese ores of India also go half-way round the world
for treatment. The same applies to the asbestos and chromite
in which this country is so rich, and to other products, like
corundum, which is largely supplied by the Transvaal. The
enormous copper deposits of the Congo are still only scratched,
and the rich zinc ores of Northern Rhodesia are only just
being investigated, Mhile absurdly low-grade deposits of both
these metals are being actively worked in Germany and
elsewhere. The war has drawn attention in the most forcible
way to some of these anomalies, and there can be no doubt
that the Old World centres of civilisation will have to face
the passing of their supremacy in the metallurgical industries
to newer lands with larger areas and proportionately greater

rRESIDKNTIAL ADDRKSS— SECTION B. 45

natural resources. It is inevitable in the long- run that those
places with the larg-est deposits of each particular mineral
Avill develop into the greatest centres of production, unleas
they are wholly deficient in fuel or other sources of energy.
If this country has the great future before it which most
of us believe it has, we must show that its internal resources
are sufficient in kind and in amount to form the basis of those
industries which are necessary to make it to a great extent
independent of importation from overseas. Here the aid of
the economic geologist is of the utmost value. Personally,
I believe that the ITnion of South Africa can obtain from
within its borders supplies of almost everything that is
essential for its industrial development, and the same may
be said with equal confidence of Rhodesia. Though the latter
cannot claim to rival the gold returns of the Rand, it possesses
an almost unequalled variety of mineral products, actual or
potential. Already it leads the world in its output of chromite
and of the higher grades of asbestos, and the time cannot
be far distant when its enormoiis resources in coal, zinc, iron
and copper ores will be exploited as their output justifies.
These will, no doubt, have their development assisted by the
employment of one or other of the great sources of water
power Avhich exist at various points in the territory.

We must not, however, be led away into the tempting
pursuit of patting ourselves on the back, so to speak. It is
my intention rather to show what practical steps can be taken
to foster the development of the great supplies of the various
mineral products which we believe exist. In this connection
I shall confine myself chiefly to a consideration of the channels
into which the activities of the mining geologist can be
directed, and incjuire in Avhat way his services may be utilised
to most advantage.

It may at once be said that a considerable part of the
foundation has already been laid, though it is not altogether
complete, and requires a number of g^aps to be filled before
it can be utilised as a base for the superstructure we hope to
build. Nevertheless, during a period lacking- the excitement
of sensational new discoveries, the descriptive side of the
subject has made good progress, and we now have as a result
a fair knowledge of the mode of occurrence of a large number
of the more important mineral deposits in the country. At
the same time, a good deal still remains to be learnt, more
especially with regard to certain of the base metals on which
our future industrial ju'ogress so largely depends, and it is to
l)e hoped that contributions to this branch of the subject will
not be less numerous in the future. Mining eng-ineers can
do much to help on this department of geological work.
Points of great value can often be gathered from their reports,
and these would be still more useful if the writers would
make a practice of having- their rocks named by competent
authorities. It is very misleading- to have a rock referred
to as a " quartzite," for instance, when a petrolog-ist could
at once have pointed out that it was of igneous origin, and
the reports of the Geological Suiveys might be utilised to

40 rEK.SIJ)K-\'iIA]> ADDltKSS SKCTIOX 13.

give a general idea of tliQ geology much more frequeiitly
tliaii is the case. Another jjoint to Avhich reference maj- be
made is the necessity of discrimination between various types
of association in dealing with the relations between ore-bodies
and rocks. This concerns the mining geologist as much as
the engineer, who does not profess to be a geological expert.
Thus, there is a world of difference between the occurrence
of an ore-body in a rock and the mere presence in the vicinity
of some rock assumed to have a genetic connection with the
deposition of the ore.

This leads me into what is more especially the province
of the mining- geologist. In discussing the origin of ore-
bodies, it is clear that there are two perfectly distinct types
of genetic association. These are well illustrated by the ores
which are usually found in close association with acid and
basic igneous rocks respectively. There are, it is true, a
number of very important metals — gold, silver, copper, lead,
zinc, antimony, etc. — which appear to have no very well-
marked tendencj', excejDt over limited areas, to occur in
connection with one particular rock type rather than with
others. But with other minerals the case is different. There
are, in fact, two very well-defined groups of minerals, one of
which occurs almost exclusively in conjunction with basic
rocks like serpentine, while the other is almost invariably
associated with acid rocks like granite and its offshoots. The
basic group includes tlie metals platinum, chromium,
manganese, nickel and cobalt, as well as magnesite, talc,
asbestos, and also the diamond. The acid grouj^ comprises
such metals as tin, tungsten, bismuth, molybdenum, uranium,
tantalum, zirconium, cerium and thorium, together with
minerals like mica and, perhaps, graphite. Now, a little con-
sideration will show that some of the leading members of
these two groups differ radically in the manner of their
association with the rocks which appear to control their
occurrence. The minerals of the basic group are almost
invariably found inside the limits of the rock mass with which
we associate them. Platinum and chromite, for example, are
found in such rocks as serpentine and its allies, and these
rocks form both the matrix, or lodestuff', and the country of
the deposit. With some of the minerals of the acid group
the case is ciuite different. Tin and tungsten, for instance,
and notably the richest and most persistent deposits of those
metals, do' not occur as a rule in a granite matrix, or even
with granite as their country rock. They generally favour
a ciuartz-ore matrix, which seems to be connected with granitic
intrusions, as shown by the invariable presence of granite
in the near vicinity, but they frequently have sedimentaij
or metamorphic rocks forming the walls of the lode. This
obviously indicates a difference in the nature of their genetic
connection with the associated rock types, but, as a discussion
of the matter is likely to lead us into regions where con-
troversy is still acute,! do not propose to go further into it
here.

PKKSI])KXTIAL ADJJRESS SECTION ii. 47

At tliis point it seems desirable to emphasise the
necessity of caution in applj-ino- current theoretical con-
ceptions to particular occurrences which may be encountered,
for theories which are widely held to-day may become
discredited within a surprisingly short time as knowledge
advances. As an instance of how detailed investigation of
the facts may alter the views held as to the genesis of certain
ore deposits, I may cite the case of some of our Rhodesian
gold reefs. The theory that I myself formed, after making
a preliminary examination of several mining districts, was
that they were intimately connected with the intrusion of
the great granite masses which are so prominent a featiu'e
of Rhodesian geology, though I pointed out that there were
some which appeared to be of earlier and some of later date.
Several years after, Mr. Maufe drew attention to the close
association of many reefs with finer grained acid intrusive
rocks, though he did not clearly indicate whether they were
all of one age. It is quite probable that I had not allowed
enough weight to the influence of the smaller intrusions,
some of which certainly show every evidence of being-
genetically connected with the deposition of gold ores. That
it does not do, however, to dogmatise too freely on apparent
associations is well illustrated by what is now known of the
Sebakwe district. The reefs there include those of the largest
gold producer in the country, namely, the Cxlobe and Phoenix,
as well as the Gaika, Moss, and other smaller properties. These
are all situated along the margin of the granite, and might
well be claimed as typical examples of the theory of close
association with the intrusion of that rock. Closer examina-
tion, however, shows that the reefs cut across certain dykes
of the granophyre family, which mav be termed felsites, or
quartz-jjorphyries. The latter are clearly younger than the
granite, and it might, therefore, seem that the deposits belong
to the groujj of which the importance has been emphasised
by Mr. Maufe. The fierce light of publicity which shone
upon the Globe and Phoenix Mine during the great lawsuit
over the right to work under the John Bull claims has never-
theless had as one result the demonstration that there are
still younger igneous rocks which have to be taken into
account. These are a series of dykes ranging in composition
between dolorite and porphyrite, and usually much altered
with production of carbonates, though not affected by the
more intense agencies of metamorphism. These were first
noticed at the Gaika Mine, and later on in the Eennie-Tailyour
Concession, and I had been puzzled by the fact that they
occasionally carried gold. The observations at the Globe and
Phoenix showed that they cut both granite and quartz por-
phyries, but were nevertheless intersected by the reefs in that
mine. We thus see how more and more detailed knowledge
may gradually alter our opinions regarding the genesis of
particular ore deposits, though each one appeared in turn to
fit in admirably with the facts as far as they were established
at the time. It may be noted that association with the basic
dykes seems clearly indicated in this instance as the final

48 PRKSIJIEXTIAL ADJJRESS SECTION B.

solution of tlie problem, since there is a single intrusion,
entirely similar in every way to tlie otliers, wliicli cuts
throug-li the reefs near the seventeenth level, thus assig-ning
their formation to the period during which the dykes were
being- intruded.

What is really of most value in discussing ore deposits
is unquestionably detailed field work, influenced as little a.^
Ijossible by theoretical considerations. As an example may
be cited the close examination of the AVitwatersrand goldfield
carried out by Dr. Mellor. It is true that Dr. Mellor has
made certain theoretical deductions from his observations
which I have publicly dissented from. It is for this very
reason, and also on account of the attacks recently made
upon the official interpretation of the Rand's g-eological
structure, that I specially desire to emphasise the importance
of such a detailed scrutiny of these great gold deposits. We
may not be at all inclined to agree with the conception of
the Rand gold as being of alluvial origin, but there can be
no two opinions on the part of any unbiased observer
regarding the value of the held work itself. It may not be
out of place to add that people would do well to think twice
before accepting the ideas of a school who do not object to
be described as " unorthodox geologists." In particular,
attention may be drawn to tlie absolutely unequivocal declara-
tion recently made by Dr. Rogers that the reefs of the East
Rand can be followed without any break right through the
point where a fault is postulated by the unorthodox, which
is absolutely necessary to substantiate certain of the
hypotheses which they have advanced.

I do not at all suggest that it is desirable to fetter the
mining geologist in any way. By all means let him theorise.
jSTevertheless, it cannot be gainsaid that his theories are worse
than useless if they cause him to overlook any important fact.
To be perfectly frank, I am strongly of ojiinion that the chief
function of the mining geologist lies in the correct inter-
l)retation of structural features. Thus, in the study of ore
deposition, the nature of the fractures that have determined
the position of the ore-body is of the first importance, if it is
related to fracturing, or, on the other hand, the fact that a'
particular occurrence has not been so determined is equally
important. Another problem which it is necessary to solve
is the relation, if any, which exists between the ore-body,
or the richer portions thereof, to adjacent roeks or rock
structures. This may involve a nice discrimination between
the essential and the accidental features in the associations
of the deposit, and although such associations have been
correctly diagnosed in certain cases — for instance, that of the
well-known " indicators " of the Ballarat goldfield in
Australia — without geological assistance, it is probable that
close study by trained observers would lead to the recognition
of many similar but less obvious examples elsewhere. Even
more important may be what is perhaps to be regarded as
applied mineralogy, namely, the investigation of the extent
to wliicli secondary processes have influenced values in the

TRESIDEXTIAL ADDRESS SECTION B. 49

upper part of au ore-Lodj', and lieuce the probabilities of the
downward extension of the valuable mineral. This is clearly
by far the most important matter in estimating- the possi-
bilities of newly-discovered lodes or mineral districts, and one
to which far too little attention has been paid in the past,
both in technical literature and in mining education. Newly-
opened properties are frequently reported on by men who may
be experienced in running- mines, but have little or no con-
ception of the influence of surface enrichment processes. Yet
comparatively undeveloped deposits require for a reasonably
correct appraisement of their possibilities an examination
made with every assistance that the scientific study of ore-
bodies can afford. Their investigation comes, in fact, Avithin
the province of the mining geologist rather than that of the
mining engineer. At the same time, the raw geologist may
be as dangerous a guide in certain cases as the so-called
" practical man," because it is absolutely necessary in solving
the problems presented by mineral lodes to have due regard
to those severely practical considerations Avhich may be
summed up under the head of working facilities.

There are, of course, instances in which secondary
enrichment processes may render a lode workable to a con-
siderable depth, even when the primary ore is altogether
unprofitable. In the case of such metals as iron, the masses
of ore produced in the course of surface enrichment are often
so large that they constitute by far the most considerable
of the deposits which are commercially exjiloited. Then, too,
in dealing with metals like copper, zinc and lead, the possi-
bility of impoverishment of the outcrops, or even the removal
by leaching of much of the metal-bearing mineral at various
other points, especially in the neighbourhood of water-level,
must be borne in mind. An iron-bearing gossan may be all that
represents a rich copper lode on the surface. We have also
to consider what may be termed " mixed deposits," such as
copper-tin lodes or lead-zinc lodes, in M'hicli one metal tends
to replace the other in depth. Thus many of the Cornish tin
mines began their career as producers of copper, while the
great Broken Hill lode in Australia, and that of the same
name in Northern Rhodesia, commenced as producers of lead,
but are turning into zinc mines as they are followed downward.
The problems presented by such deposits are of great com-
plexity, and experience alone can teach the observer how to
avoid the manj' pitfalls which beset his path.

Turning to another side of the science of ore deposits,
we come to the elucidation of the blanks and breaks which
may occur in the distribution of the valuable minerals through
a lode. In many lodes a particular section is often much
the richest, and may alone be 73rofitable — for instance, the
footwall may be very rich and the rest so poor as scarcely
to be worth mining*. Still more frequently the valuable
portions form distinct patches, M'hich may be sufficiently well
defined to constitute what are commonly known as shoots
of ore. Then, again, we may have another kind of dis-
continuity, due to the action of such geological processes as

50 PRESIDEXTIAL AJ)]mESS SECTIOX B.

faulting', or the iutrusion of ig'ueous rock subsequent to tlie
deposition of the ore, which may result in all kinds of
disturbances and displacements. These constitute a very
important branch of the study of ore deposits, and are one
of the most frequent occasions for g-eological assistance to
be called in by those responsible for the conduct of mining
operations. In all cases of discontinuity, whether due to
faults or intrusions, or merely the result of the circumstances
imder which the ore was originally deposited, the important
point to decide is whether there is a chance of jiicking up
the ore-body again or not. The mining geologist must find
out whether the displacement is large or small ni amount and
indicate its direction, or, if there is no displacement to account
for the pinching out of the lode, he must give an opinion
as to whether the association of the pay-ore with particidar
geological features is such as to warrant the expectation of
encountering fresh shoots along the strike or in depth. There
are even cases where perfectly distinct ore-bodies may be
presumed to recur regularly in conjunction Avith special
structures — a well-known example of this is provided by the
" saddle reefs " of Bendigo, in Australia.

I have no desire to labour these points on the present
occasion, nor do I propose to deal with such strictly geological
problems in connection with mining as the location of con-
cealed coal seams or oil pools. It will be sufficient to point
out that the kind of work rec[uired in the investigation of
the mineral resources of a country is far more closely allied
with that necessary to lead to success in drilling for oil than
is generally realised, although in South Africa it is more
obvious than in many other countries. Por instance,, the
definite location of the Rand " Main Reef " series in the
most remote district would clearlv justify the expenditure
of capital to open it up on some scale. The mere identification
of a particular rock as similar in every respect to another
already known as an ore-carrier is, in fact, a most useful
piece of information, and should lead to close examination
of its outcrop. Then, again, the determination of the various
periods of ore deposition may be of great assistance to those
in search of valuable minerals, even if only by warning the
prospector not to waste his time on rocks laid down or
intruded, as the case may be, subsequent to the last period
of mineralisation. These periods may, of course, differ for
different metals — a fact which must be clearly borne in mind.
It will be seen that theory does not enter at all into most of
these questions, or only in very small degree. Tor instance,
we should bore for the Main Reef just_ the same, whether
we considered its gold as alluvial, following Gregory, Mellor
and others, or as of magmatic origin in the way that Horwood
contends.

In conclusion, I may briefly refer to the fact that
industrial progress is in some degree directly bound up with
the conduct of mining operations. The modern tendency is
undoubtedly more and more for the mine to become other
than a mere producer of raw material. In America especially

I'RESIDEXJIAL ADDRESS SECTION B. 51

one sees suck readily saleable products as sheets, rods, pipes,
wire, alloys, metallic pigments, etc., being put on the market
rather than concentrates, matte, or unrefined metal. jS'ot
only is this the case, but there is another important side to
the question. The economical/ treatment of many ores
demands cheap supplies of certain chemicals. Thus the
extraction of zinc, or copper may often be best eft'ected by
leacliiiig with sulphuric acid. In localities far from the present
centres of production this involves undertaking the manu-
facture on the spot, and it need hardly be said that this is
a big step towards further industrial developments. Such
instances coidd readily be multiijlied, but it suffices for my
present purpose to point out that under existing conditions
we can enter upon these commercial undertakings without
fear of being undersold by Europe or America — a sure
indication of the progress which is bound to follow in the)
near future from the utilisation of our abundant natural wealth
under intelligent technical direction.

CAUSES LEADIXG TOWARD PROGRESSIVE

EYOLUTIOX OF THE FLORA OF

SOFTH AFRICA.

By T. R. Sim, D.Sc, F.L.S.

Presidential Address fn Seefinn (', delivered J nhj 16, 1920.

Wherever one travels in South Africa changes are seen
to be going on in the vegetation and in the nature of the
veld, and the longer one lives in South Africa and observes
what is happening, the more evident does it become to him
that the actions of civilised man are usually either directly
or indirectly connected with these changes, and that these
actions are often self-centred and exigent to a degree which
is not permanently beneficial to the community, and which
tends toward further and more serious changes in the future,
on which the life of South Africa as a habitable region
depends.

I refer not only to changes in the local floras, but also
to resultant changes in the climate as a whole, influenced, if
not brought about, by these flora changes. I am led to take
this subject because with time and travel I see more definitely
the course and cause of changes constantly taking place under
our eyes upon everything which comes under our cognisance —
changes usually regarded as natural changes, which, o7i
account of their insidious nature, often pass unnoticed, or, if
noticed, are considered either trivial and not worth attention,
or else unsurmountable and so beyond our powers, neither of
which opinions are exactly- correct.

52 PRESIDENTIAL ADDKESS SECTIOX C.

These cliaiig-es include the evolution of the flora of South
Africa as it is going- on now — the evolution of the flora as a
whole, and of parts of it — of regions, districts and areas ; the
reflex action of that changed flora on the climate, and again
of changed climate on the flora — evolution which, though
insidious, can be seen and recognised during a lifetime, even
without written records, and all bearing a trend which is
unmistakable. That trend is not necessarily the evolution of
new species, but rather the gradual disappearance of what
were climax types and the substitution of species of a more
xerophytic nature.

Man and his actioiis play an important part in producing
this change, for not only does he bring with him the weeds
and survivors of cultivation, but through cultivation he
destroys the natural herbage, and gives these aliens oppor-
tunity for naturalisation, of which some of them have freely
availed themselves, sometimes to the exclusion of native
species.

Cultivation is, however, a necessity, and its attendant
troubles are more or less inevitable. AYe have nothing to say
against good cultivation in which the original flora is displaced
by cultures yielding permanently returns of more value than
the original, without haviiig other detrimental effect.

But it is rather with pastoral agriculture and with bush-
cutting, their methods and their results, that I wish to deal,
especially in reference to how these are affected by natural
conditions, and how in return the surrounding conditions are
affected by them.

In order to get a clear grasp of these reflex actions, it is
necessary to review separately several rather disconnected
subjects, and then bring their bearings together as a final
clause. So far I have suggested man as an important factor,
and the advent of civilised man as a starting ])oint for the more
rapid evolution of South Africa's flora and climate.

Xatural Causes.

But there are also natural causes at work, far beyond man's
control, though still some of their results may be influenced
by what man does. I refer particularly to the phenomena con-
nected with climatology — phenomena whose influences are the
final factors in plant life and in plant distribution, and on
that account I ask the indulgence of Section A of this Associa-
tion, if I deal at some length with a subject in which Section A
and Section C overlap, as a necessary introduction to what
follows.

The flora agrees with the climate in every case; a change
in the climate brings in its trail a change in the flora, whether
that change take the form of adaptation of existing species,
increase or decrease in the representation of existing species,
or their substitution bv other species.

Bolus and Wolley-Dod (1903), p. 231, find that grass burn-
ing and bush-fires tend to destruction of si)ecies and consequent
greater uniformity, but not necessarily greater usefulness of
the vegetation, and that the tendency is slowly and gradually

rEKSI])KXTIAL A])])RESS— SKCTIOX C. 53

toward the extinction of the ancient flora. But any change
in the flora eventually has an effect on the climate also, as I
hope to show further on.

Climatic Cycles.

That cyclical changes of climate occur everywhere is now
well established — the causes may not be clear or convincing,
the duration of the cycle may be irregular and unreliable, but
the effects are pronounced, though not always direct, or even
easily connected.

The cosmic readjustments whi(di have produced in succes-
sion one or more whole-world glacial periods of enormous
duration, alternating with periods of more or less torrid
equatorial conditions, have rendered necessary gradual read-
justments of the flora and fauna capable of enduring each new
condition as it came into existence.

But climatic cycles of much shorter duration, distinctly
affecting the flora and fauna, have also been established which
apparently have their origin in the more or less regular cycles
of sunspot production, the periods of maximum activity
extending over several years, and by interfei'ence with solar
radiation producing on earth conditions of less intense light,
with consequent effect upon barometric pressure, upon rain
production, and upon the vegetation and the fauna.

The Senate Select Committee on Droughts, Rainfall and
Desiccation, 1914. reported, inter alia, re rainfall: "4. (c)
That while there is some evidence to support the theory of the
periods of maximum and minimum rainfall corresponding with
certain cycles, there are not sufficient data available to define
any such cycles."

That there occur periods or seasons of heavy rainfall at
considerable but more or less irregular intervals, with much'
drier years or periods intei'vening, has long been recognised in
South Africa as well as elsewhere, and for many years these
have been correlated with sunspot phenomena.

Close study in America and in Europe (see writings of
Douglas, Huntington, Clements, cited at the end of this paper)
place this beyond further doubt, especially as it is fully
supported by rings showing annual tree growth for 2,000 years
past, and I advise those who still doubt this relationship to
investigate the matter further before they commit themselves
to op])osition views.

The relationship appears to be an indirect rather than a
direct one, apparently in the direction of a direct influence
on the migration of the banc factors, which in due course, but
not everywhere contemporaneously or to equal extent, affect
local climate, and naturally not always in tlie same direction,
since if extra pressure exists in one place it corresponds with
reduced pressure in another, or, in other M'ords, increased
rainfall in one locality corresponds with the absence of rainfall
somewhere else.

The sunspots themselves appear with an irregular cycle,
which ranges from seven to seventeen vears between the

54 PKKSIDKNTIA]. AJJJ^EESS SKCTIOX C.

maxima, the number of spots occasiouallj'- reaclnii<^" tew or
none, then gradnally increasing* j^ear by year to a maximum
varying" from 50 to 150 spots, then fliminishing- again
gradually to few or none. With such a wide variation of
cycle duration and of maxima, it is, of course, impossible to
predict years ahead, but it is found that the average cycle
since sunspots could first be counted has been slightly over
eleven years, and that the growth-ring records of trees corre-
spond with the known cycles during that period, and so can
be accepted as proof for earlier times. What the exact
climatic effect is, or how it is produced, maj^ be debated, but
it seems that the more spots the less luminous or the more
veiled is the sun ; that there may be one or more successive
years of high or of low sunspot activity ; that the whole baric
system of the earth is affected thereby in its migrations, and
that one result is that hot and comparatively rainless seasons
occur when sunspots are few, while duller, colder and more
rainy seasons occur when or soon after they are abundant.
I say " soon after " because the local action anywhere is not
altogether a direct one, and though the migrations of the
baric system and of anticyclones, etc., may he a direct action,
these sometimes affect local rainfalls one or even two years
later, and in methods of local ap])lication which, so far
as South Africa is concei'iied, are still far from clear, though
this delaj^ed action has been noted in connection Avitli the
eastern rainfall.

Although sunspot appearances and reactions have been
carefully followed and detailed in connection with the Northern
Hemisphere, little has been published concerning these
phenomena as thej^ affect the Southern Hemisphere, but just
because of the Senate Select rommittee's finding, already
mentioned, that " there are not sufficient data available to
define any such cycles." there is the more reason why this
subject siiould receive the closest investigation, not only as
an abstract and interesting theory, but as a proved cause-
and^effect elsewhere, and also on account of its intensely -jirac-
tical bearing on the possibilities and probabilities of plant-life
and ag-ricultural operations in near future years from any
given date, some of the North American States having' their
cycles of " fat years " and of " lean years " in legard to
ordinary agricultural crops, directly related to tlio weather
cycles. In Africa it is clear that Joseph kncAv something
about the result, if not the cause, when he stored grain in
Eg-ypt durino' the several full years, which he predicted would
be followed by lean years 4,000 years ago.

All writers on the subject agree lliat. in addition to the
definite sunspot cycles, there are other rainfall cycles, some
longer, some shorter, simultaneously at work, the cairses of
which are less clearly understood, but wliich croj) records
and tree-ring records show to be fairly constant, and it is
known that when several of these cycles fall due at one
time, and occur when due, ihe rainfall I'ecord becomes an
unusuallv heavv one.

rKKSIJ)ENTIAL ADDllKSS SKCTIOX C. 55

The exact correspoudence of certain increases and
decreases of rainfall (four rises and four falls) shown by
Arctowsivi (1915) during the period 1900 to 1910' for certain
stations in Peru, Mauritius, Madagascar and South Africa
(Bulawayo) (see Clements, p. ooO and fig. 29). indicate that
the SoutLern Hemisphere has some independent general factor
producing simultaneous coincidence in certain localities which
is worth further investigation, as also is the distribution of
local variations arising therefrom.

In 1888 Mr. D. E. Hutchins ])ublished '; Cycles of
Drought and Good Seasons in South Africa"; in 1890 he
brought the same subject before the Royal Meteorological
Societj', London, and he further dealt with it in the Cape
Agricultural Journal, 1897, xi, p. 701,* and 1898, xii, pp. 138,
211 and 26T. In all these he claims that Soutli Africa is
subject to three rainfall cycles, of different period, working-
simultaneously, viz. : —

(1) " Storm cj'cle, bringing the heaviest rain to western

winter rainfalls, but usually only wind to eastern
stations. Period nine and ten years alternating "
( = Ilusseirs nineteen-vear cvcle, Cape Arjric. Jour.,
xii, 272).

(2) " Meldrum's cycle, liringing the heaviest rain to

eastern summer rainfalls, 1nit usually little rain to
western stations." This lie previously' called
" Mitigation cycle " ; period, 12'5 years.

(3) Sunspot cycle; period, ll'll years. — "The least

important, or at any late the least powerful
and punctual, of tlie three South African weather
cy(des."

These three cycles so rarely fall due at one time that it is
126 years since they were so near together as happened in
191G-1917, which years Hutchins predicted thirty years ago
would be a time of unecjualled eastern rainfall, in which, at
most localities, his prediction has come wonderfully correct,
as also have others of his ]U'edictions as to rainfall and also
as to drought.

The net result of all this, however, is that if Hutchins'
theory is on a sound basis (which I neither affirm nor contra-
dict), and apart from any deferred rains which may fall up
to 1920, the eastern rainfall may be expected to be less yearly
for some years from 1918, and not much again u]) till 1927-
1930, but that the south-west districts should get good rains
about 1926, Avhich may extend as storms to the south-east
coast also, and that towards the close of the dry period above
mentioned intense desiccation is to be expected throTighout
Soutli Africa, except on the coast belt and sub-coastal
mountain ranges, since the rainfall of seasons 1917-1918 and
of 1920. which kee]i tlie average fairly high, mostly went as

* Reprinted as an Agricultural Department Bulletin, with correc-
tions, for, nnfortmiately. p. 709 in the A(jric. ■Journ. has^ many evident
printer's misplacements as to due dates.

5G PEKSIDKNTIAL ADJJKKSS SKCTIOX C.

rapid floods to the ocean, and only a small portion of it soaked
in to form a reserve for the next ten j^ears to draw upon.
Also it is to be expected that after the few rainfall cycle
3'ears just mentioned, another long^ period will occur before the
portions of South Africa fed by the south-east winds will be
well supplied again, the cycles g-ettino- g-radually better
distributed thereafter.

That the South African records are insufficient as a basis
on which to frame or to condemn cycles suspected to be at
work locally is admitted, especially as tlie summer rainfall
records are all upset hj being divided into calendar years
instead of into seasonal years, but that is no proof that cosmic
cycle causes known elsewhere are not active here also ; all
that is required is that we study and recognise what is going
on around us.

I trust, liowever, that I liave made clear how it happens
that periods of heavy rainfall alternate in cycles, with periods
of intense drought and desiccation ; that these cycles are of
more or less irregular duration between seven and seventeen
years, with average of eleven years : that other cycles of shorter
duration are concurrent, but of different average j)eriods and
acting differently and in different localities ; that when these
different cycles happen to overlap, the effect is increased in
each direction; and that all these cycles are quite beyond man's
power of control.

It is held by some that, if such be tlie case, it is beyond
the power of man to influence in any way the rainfall which
nature, through sunspot and other cycles, baric migrations,
day and night breezes, and other means, arranges for South
Africa; in other words, that wliat is predestined will happen,
and that what is lifted by evaporation from tlie ocean, whether
that quantity be large or small, is what we have to be satisfied
with and what we have to take as it comes. That, however,
overlooks the fact that the same moisture is often precipitated
more than once; that all moisture, either evaporated from the
earth's surface or transpired by plants, is then available in
the atmosphere to fall again as rain or dew; and that the
amount either evapoiated or transpired is largely regulated by
the vegetation covering the earth. Where there is a dense
grass-sward, or a forest liumus-bed covered by a forest canoDV,
nearly the whole rainfall is retained until it either sinks into
the subsoil, is slowly evaporated, or else is used by the vegeta-
tion and again transpired. Where there is little or no
vegetation the surface is usually baked hard, rapid infiltration
of rain-water into the soil is impossible, and the result is that
almost all the rain that falls there rushes down some river to
the sea, caiTying soil along with it and producing erosion
which in time becomes serious, and not only carries away the
flood-water, but also drains away whatever moisture may find
its way into the soil and subsoil. It is in tliis connection that
man's influence is greatest.

By grass burning he produces a condition of no vegeta-
tion, so for months there is no shade, and for a year at least
there is no humus, and, consequently, when rain does fall

PRESIDENTIAL ADDRESS SECTION C. 57

there is notliiug- to retain it ; almost the whole supply rushes
off to the river; little or none of it reaches the subsoil, and the
death of deep-rooted plants results; the small supplies wbicli
reached the surface soil soon evaporate, and so the surface-
rooting* plants die, and the result is that a change of vegetation
from mesophytic to xerophytic is inevitable, usually taking' the
form of a change from red grass (Anthistirio) or blue grass to
wire grass (Atistida).

Repeated burning — whether annual, biennial or at longer
intervals — only accentuates the evil, and in the absence of
humus protection the half-dry crowns and growth-buds of the
better types are scorched or burned, while the xerophytic types
adapted to such treatment manage to survive and so become
the dominant vegetation.

Summer burning is even more regularly destructive, for
though each species has its season of soft growth, more species
are liable to damage during summer than during winter, hence
" summer burns " often leave their mark for many years.

In what is really good grass-veld tliere is always the
tendencj^ to recover some time if the opportunity is given,
i.e., the rainfall and general conditions favour the better kinds
rather than the xerophytes, but in too many cases the farmer,
finding his veld mostly composed of wire grass (Arisfida),
which is only edible during the first feM' weeks of its growth,
resorts to fire again on purpose to clear oft' the indigestible
old growth and allow stock to feed for a fortnight in spring
on the more tender young leaves. Thus it happens that sooner
or later the wire grass gives place to bare patches, or to
patches of summer annuals or to xerophytes of more pronounced
type, the run-off of rainfall is aggraA^ated, erosion begins and
the locality eventually becomes devoid, not only of useful
vegetation, but also of soil. It is eroded to the rock, and the
surface is only covered by whatever disintegrates from the
rock below — even that is often waslied away in slabs or stones
as these become free, instead of being reduced to soil or clay,
as happens when the disintegration takes place under dense
vegetation.

In a recent pamphlet, " Soil Erosion and Conservation,"
I have dealt with over-stocking, A-eld tramping, water con-
centration and bad farming — all leading to donga formation,
erosion, desiccation and desolation in tlie same way as grass
burning, and often acting in concert with that practice.

Thus while under a constantly unl)urned and undamaged
vegetation-blanket humus accumulates and the soil deepens
and becomes more and more fit to retain moisture and to
maintain the higher standard of vegetation known as plant-
succession up to a higher climax tvpe, the reverse is the case
where the vegetation is burned off. or tramped off, or over-
grazed. What vegetation remains graduallv dies off',
xerophytes hold the bare surface until erosion displaces both
the plants and the soil, and then when the rock is readied even
that breaks up by insolation and radiation, and wlien a flood
does happen, these stones, by friction, aid the torrents in
causing further erosion. These two courses — the one upward

58 rRESiJ)i:xTiAL address — section c.

and tlie other downward — are tlie natural sequence of events
begun with man's actions, either toward protection or toward
destruction.

In the case of forest destruction the change is even
greater, for if we look on good forest as the highest climax
type, and remove that forest or reduce its canopj^ Avithout due
care as to the rapid recovery or renewal of that canopy, it
promptly becomes, through man's agency, either rough grass
land or more or less unstable mixed vegetation which is liable
to pass into erosion before it ever g^ets settled into grass-veld,
though the latter is its natural tendency if left alone, prior to
the next step upward in the succession, which in forest con-
ditions would be forest, if the opportunity were given. But
when the down-grade is once begun, man's action harrlh' ever
helps recovery, but much more frequently helps to change the
position from bad to worse, till eventually a suitable forest
slope is Avashed to the bare rock, and can no longer maintain
any vegetation.

Dr. I. Croumbie Brown uttered this warning very strongly
in his many writings over fifty years ago, but the public still
ignores the plain fact, and farmers farming stock on what is
naturally forest land sincerely believe they are doiug the right
thing, or following the only possible course, in burning for
immediate returns, irrespective of the ultimate result.

Climatic Changes.

Let us now look at the result of this destruction of vegeta-
tion upon the climate. Where the process involves the change
of a dense canopy and hum\is, whether of forest or of grass,
with its soil-protection and moisture absorption, into a bare
surface from which the run-off is immediate and intense, or
into any of the succeeding lower stages in which the run-off
and erosion are even worse, the atmosphere naturally loses
all the moisture, which then goes to form the ri^'er flood, or
even the river's regular flow, all of which water, when retained
by the humus of the undamaged surface, eventually finds its
way into the atmosphere and falls again as rain, sometimes
time after time.

We can onlj' regard the flood-water and also much of the
ordinary river flow as so much water wasted, except in so tar as
it is used for irrigation or household or power purposes, and we
can only regard what sinks into the subsoil, or is transpired
or evaporated, as so much water saved for further use. In
other words, the less flow to the river indicates the greater
saving of water by natural means for further and immediate
use inland. I am aware that this is contrary to a common
idea that eucalypts, wattles and other trees of rapid growth
dry the country, and that this is shown in the reduction of
the off-flow. J^o such drying happens, however, but, on the
contrary, wherever the off'-flow is reduced that much water
is saved from flowing away and is passed into the atmosphere,
ready to fall again. It does sometimes happen that these trees
tax their sites heavily, which indicates that these particular
sites are not well suited for such trees. But wherever the

PEESIDKNTIAL ADDEJ-:SS SECTIOX C. 59

trees continue to live yeax* after year, tluit i- evideiue that they
are receiving what moisture they require, and that the channel
of escape for the moisture into the atmosphere is a more useful
one than when the escape was by means of a river into the sea.

How Much Water is vSaved.

A very pertinent question is how much water is it possible
to save by this means. The savine- in anj- case is the propor-
tion of the rainfall which does not run ofi'. The larg^er the
area under these vii^orous trees, the gieater is the saving in
moisture and the more is the river flow likely to be reduced.

Then there comes the inquiry : If that be so, how do grass
and forest herbage regulate the off-flow required for domestic
and economic purposes y It is easj' to see that water retained
and prevented from running off during rain obtains thereby
an opportunity of sinking into the soil and subsoil. The
humus of the forest and the humus of decayed grass foliage
alike act as a sponge and keep the water till it soaks in. That
water may take da'\'s, weeks, months or years to be all used
by the vegetation, but until it is so used a slow and steady
infiltration to some stream or underground reservoir is going
on — luuch more permanent than the flood-and-drought supply
of burned veld, but varying in duration in accordance with the
demands of tlie vegetation and the nature of canopy and of
humus under which it abides.

Naturally, a tree of rapid growtli, uiu\ inoducing little
humus or canopy when young, may dry the surface soil
considerably, but that drying, when it affects the tree, brings
down foliage, makes humus, and produces growth in accord-
ance with the supply available.

How Rainfall is Produced.

But now let us trace that moisture which through
tianspiration and evaporation again becomes part of the
atmosphere.

Temperature, atmospheric pressure and altitude govern
what humidity the atmosjdiere can carry at any particular
place; as these change, so also changes the point of saturation,
and as soon as that is reached or passed, de])Osition as rain,
mist, dew or snow takes place. Consequently an atmosphere
which is capable of absorbing all the moisture that is
transpired and evaporated by vegetation many be incapable
of carrying that moisture if ii happens to meet a colder current,
or rises into a higher altitude where the atmosphere is more
rarefied. This accounts for the vegetation being different on
rising ground from what it is on the flats below, the precipita-
tion on hillsides, and especially on the south-east slopes of the
escarpment (i.e., facing the sea breezes) being often sufficient
to maintain natural forest which cannot exist elsewhere.

If all the moisture preciDitated on these slopes ran off at
once to the sea, the country behind would get very little, but,
as it happens, a very large proportion is transpired and during
dry weather absorbed into the atmosphere and lifted till it
again arrives at saturation and falls again as rain or mist.

60 PEESIDEMIAL ADDRESS SECTION C.

This is repeated time after time, until the tops of the
]iiountaiii!5 are reached, which, being cold and rarefied, can
produce rain from a lesser actual humidity than happens lower.
This accounts for the frequent short rains, the mists and the
moisture, wliich alternate rapidly with drier intervals on the
mountains, but which give rise to all rivers or springs rising-
and flowing steadily in these elevated localities. On crossing-
the range and descending the other side, or if by chance the
descent is made on the same side, climate becomes warmer
and pressure greater as altitude is lost, and the atmosphere
then is able to carry all the moisture it has broug-ht over the
ridge or brought down from the mountain top, unless it
hapxiens to encounter a cold current or be driven high enough
to again reach saturation, in which case the raindrops or hail-
crystals may be formed at a high enough elevation to fall
with considerable A'elocity to the ground.

We already have proved that moisture transpired is
moisture saved and banked in the atmosphere. With the
foregoing explanation we are now able to see that the more
actual moisture there is in the atmosphere, the sooner will
saturation be reached at any point, and also the more flow will
there be in the overberg rivers and the higher relative
humidity in the general atmosphere overberg. That relative
humidity may not allow of precipitation as rain, but it
produces a less arid atmosphere — one in which plants can
live and dew can be formed, a condition whicdi allows of dry-
land farming where without that moisture cultivation without
irrigation is impossible. We see much of this in the country
west of the Maluties.

This atmospheric condition also makes possible the
continuous drizzle rains, which do so much more good, and
leave so much more soaked in, than the storm-showers which
give a deluge for a few minutes, most of which goes off as
flood and is lost for ever. Three inches of rain drizzled during
three days gives practically no off-flow from good grass-veld
or forest, but three inches of rain falling as a deluge during
an hour on eroded Karroo does much immediate flood-harm and
no permanent good.

A Dry-Blanket.
Even between the Indian Ocean and the mountains,
although there are several steps Avhich intercept clouds and
so form sour-veld mist belts, the intervening thorn-veld flats
and valleys are so protected by a " dry-blanket " (i.e., an
atmosphere in which pressure and temperature are sufficient to
carry much moisture without reaching saturation) that less
rain falls- tliere than on the mountain slopes, and more or less
arid conditions prevail, which causes the flora to be either
xerophytic or to wilt, since though vegetation transpires
freely the supply of moisture from the soil is small or spasmodic.
As in all climatic variations, the extremes kill. It is the
occasional extreme drought or ariditv which controls the flora
here, in so far as that is not controlled by fire. Burned veld
naturallv increases the local aridity, as well as that of all

PEESIDE^-TIAL ADDRESS SECTION C. 61

neigliboiiiiug' valleys, whereas imburned veld has a surface
moisture of its own, aft'ectino- not only the local dry-blanket,
but also improving matters in these neighl)ourino' valleys.

A very marked case of moisture cut oft: by the ocean
T^inds being' intercepted by a mountain range is the Zambesi
delta, including the country from Inhambane to Mocambique,
which, being- screened from direct long distance ocean Avinds
by Madagascar, has a forest flora of an exceedingh- xerophytic
leguminous type up to the foothills of the mountains, a con-
dition one would hardly expect in such a climate as this area,
otherwise enjoys.

Eaix from the Xorth.

The rains coming from the north with the annual southern
journey of the sun and of the tropical cloud-belt act much in
the same way as those from off the sea {i.e., the moisture is
carried in a temperature and pressure which can maintain it
until cold air or mountains intercept, when rain falls or
moisture is deposited). In this way much of the country has
a perpetual dry-blanket, in a large area so arid that the name
Kalahari Desert has been applied to it, though not by any
means unfit to carry xerophytic vegetation, and it is a notable
feature that from Johannesburg to Pretoria northward and
westward hill slopes having northern aspects have better
ligneous vegetation than other slopes, which is the reverse of
what happens further south and east. But the presence of
that dry-blanket there, as elsewhere, usually brings rain in
torrents for a short time only, and seldom as a continuous drizzle
rain, when it does happen to rain.

Xature of the Raixfall.

The Senate Select Committee arrived at the conclusion :
" That all aA'nilable evidence goes to prove that there has
been no definite diminution in the rainfall of South Africa
during- historic times." But that there has been variation in
the distribution and nature of the rainfall is admitted, as also
increased desiccation.

Nothing is proA-ed one way or the other in regard to the
total annual rainfall, nor can be for a long time, since the
long-period recording stations are mostly on or near the coast,
and in the south-west or in the Karroo, while the longest-period
station is the Royal Observatory, Capetown, which, being both
a coast station and one directly included in the south-west
winter rain area, is in no way affected by the eastern causes,
or by biotic influences at work throughout South Africa.

But increased desiccation produces conditions less inducive
to rainfall and to repeated precipitation, and it is difficiilt to
conceive how desiccation can become more pronounced without
the rainfall in these dTy localities being affected also.

The Senate Select Committee further states : " The evidence
as to the progress of erosion and desiccation has been most
definite, and the irresistible conclusion is that many parts of
the Union, in spite of the apparent constancy of the total
amount of the rainfall, have been slowly, but surely, drying

PKESIDKXTIAL ADDKESS SECTIOX C.

up, tile rate ot (lesiccation vaiyino- with the difierences of
locality, soil and o-radients, and that sneh parts must sooner
or later become useless and uninhabitable it the process
proceeds unchecked." I o-o further than that, and sa.y that
the progress of desiccation is constantly contaoious, and that
if " many parts of the Fnion." as stated by the Committee,
are drying- up and will in time become useless and
uninhabitable, then the fate of the balance is sealed unless
active stei)s are taken to turn the tide.

C'OXCLUSIOXS.

Let us now draw together all these scattered threads and
show how man can aii'ect even the results of the cycles,
iiy maintaining the eastern grass-veid unburued, by maintain-
ing the forests or replacing them by exotic species of more
rapid growth and of greater transpiration, and by vastly
increasing' the area under such exotic trees, especiallj^ in the
grass-veld slopes and in the natural tree or scrub lands and on
the mountains, the amount of saved and redistributed moisture
is increased enormously, and so can be precipitated and again
absorbed time after time until the mountain faces are clad
with forest verdure and the overberg districts can share in
the surplus to the extent of enjoying a higher relative
humidity, a better vegetation, a more temperate method of
rainfall, and consequently less erosion than at present.

On the other hand, by continued grass burning, forest
destruction, over-stocking veld tramping, bad agriculture,
water concentration and donga formation practically all rain
that falls is drained off immediately, and so has a local detri-
mental effect. There is very little redistributed moisture, and
that little becomes less year by year ; what moisture is
redistributed is insufficient to be redistributed many times,
and in consequence mostly does not reach the summit of the
escarpment, so that there are less mountain mist and rain,
less alpine swamp, fewer and smaller mountain springs and
mountain streams, less water running regularly in the streams
running either east or west, less overberg cloud, less actual
humidity overberg, less drizzle and soaking rain, more destruc-
tive storms and hailstorms, and more erosion.

This is not an imaginary picture of what is possible. It is
a statement of what is happening now. and I have not the
least doubt but that grass burning and bush burning elsewhere
have a similar effect to that produced l)y fires on the eastern
slopes.

But carry this further. We know from long experience
that we have recurrent alternate periods of drought and of
moisture. We have reason to believe that these occur here,
as elsewhere, in cycles more or less intimately connected with
sunspot phenomena which themselves are quite beyond our
control, and are known to have come at more or less regular
intervals during the nast 2,000 years, and presumably for very
many times before that period, so that there is no prospect
of their discoutinnance. We have shown that protection aiyl
extension of the forest and grass-veld produces better climatic

rKESIBENTIAL ABUKESS SECl'IOX C. 63

ami Yeg'etalive conditions, while abuse of the forest and veld
produces a destructive down-grade tendency, not onlj^ locally,
but for hundreds of miles away. We see in many places that,
when once that down-grade tendency is started, its natural
direction is to go steadily from l)ad to worse, and when we
connect this with the fact that the above-mentioned cycles
lead up to extreme desiccation during' the later years of the
dry period even under present conditions, we cannot help
seeing- that under continued grass burning* and forest destruc-
tion that desiccation must not onlj- become more intense
annually, but that toward the end of each dry period it must
become so much more intense on each occasion that the killing'
limit for many species must sooner or later be reached, and
tliat even where grass-veld now exists, especially overberg,
tliat must sooner or later be replaced by karroo-veld. Such a
change in the vegetation naturally has a reflex action on the
climate, which, aided by the continental position of that high-
veld, with extremes of insolation and radiation, must further
affect the vegetation.

The powerful flywlieel of natural serjuence, once set in vigor-
ous motion, is beyond the power of man to stop, as is evidenced
in Northern Africa and in Arabia ; but South Africa is still at
a stage in which that flywheel may be started, either in the
direction of afforestation and grass protection, leading to
upward plant succession, accompanied by general vegetative
and climatic imin'ovement, or in the direction of veld fires,
forest destruction and down-grade vegetation, reacting on the
(dimate, which again further reacts on the vegetation, until at
last the continent is past redemption, as some parts of it now
are, and mankind as well as the fauna and flora must die a
natural dei.th.

Do not let anyone suppose that what I have had to say
goes in any way against the i)roposals now being urged in
reference to bringing the Cunene and the ( Jkavanga rivers into
or through the Kalahari. The intention in each case is the
same, namely, to increase the absolute humidity of the
atmosphere, and so aid plant succession upward instead of
downward. Everything done in this direction liel]is, while the
absence of repressive action in regard to grass Inirning and
other causes of erosion is quite as serious and as disastrous to
the general welfare of South Africa as is the drying up of the
Etosha and other lakes. These two causes acting together
threaten the habitable existence of South Africa as a whole.
To some I may appear in all this to be particularly pessimistic.
I deny that charge, however, and wish to repeat that this is a
warning given before it is too late to turn the tide, a warning
in which all are interested, whether farmers or townsmen, since
if the farmer eventually cannot exist the townsmen suffer also.

I haA'e tried to show in what directions changes in the flora
are taking place and are to be expected, apart from cultural
readjustments, and what causes are at work producing these
changes, and I strongly urge protective action, alike by the
Governments and bv the individuals; but wliile not delaving-

64 PEESIDEXTIAL ADDRESS SECTIOX C.

that action pending- inquiries, I urg-e meantime rapid progress
with tlie work of the liotanieal Survey as one of the proofs which
sooner or later will again be, demanded to show the stability or
instability alike of the flora and of the climate.

Meantime, let the destructive agencies be checked or
controlled in accordance with scientific reasoning and with
common sense.

REFEREXCES CITED.

Aectowski, H. (1915) —

A study of the influence of volcanic dust-veils on climatic
variations. — Sci., 41, 252.
BOLrS AND WOLLEY-DOD (1903) —

S.A. Philos. Soc, Trans., xiv, 3.
Clements, F. E. (1916)—

Plant Succession. — Carnegie Inst., "Washington.
Douglas, A. E. (1914)—

A method of estimating rainfall bv the growth of trees.
In Huntington's " The Climatic Factor."—
Carnegie Inst., Wash. Pub. 192. 101.
HrxTixGTOx. E. (1914)—

The climatic factor, as illustrated in arid America. —
Carnegie Inst., Wash. Pub. 192.
Sim, T. R. (1920)—

Soil erosion and conservation. — Industries Bulletin.
Series. Bulletin '^o. 47.

SOME ZOOLOGICAL FACTORS IX THE ECONOMIC
DEYELOPMEXT OF SOUTH AFRICA.

By C. W. Mally, M.Sc, F.E.S.

With Plate XXIX.

Presidential Address to Seetion D, delicered July 14, 1920.

In beginning the work of the Section over Avhicli I have
the honour to preside on this occasion, it seems advisable to
call for suggestions for the good of the Section. The
programme which we have before us will afford opportunities
to discuss subjects on which the authors of the papers have
done original work. There may be members or visitors who
would like to get information concerning some subject not on
the programme or to offer suggestions for the benefit of the
organisation of the work of the Section in future. To afford
opportunity for inquiries and suggestions, I beg leave to
propose that when all the special papers have been dealt with,
any available time be devoted to a "Symposium'" on any
subjects that may be brought forward. My purpose in making

PEESIDEXTIAL ADDEESS SECTIOX D. G5

early mention of this is to enable members to note any ideas
that occur to tliem as we proceed and present them promptly
to the Sectional Secretary, so that arraug-ements can be niade
for any member who has special knowledge of any given
subject to lead the discussion. Yoluntary discussion is highly
desirable as well. I should be very sorry if a meeting of this
kind closed without every member having had a chance to
discuss any subject in which he or she is specially interested.

Zoological Survey.

It is gratifying to note that steps have been taken towards
(,rganising the Zoological Survej'. Limited resources in men
and means are the proverbial lions in the path, and progress
will be slow until they can be dealt with.

Genetics.

The subject of Genetics no doubt occurs to everyone from
time to time, and I believe there have been proposals for the
formation of a Genetic Society, but so far as I know there has
been no practical outcome.

In view of the fact that South Africa has long since been
a trysting place for almost everj- type and race of human being,
I venture to say that there is no better place in the world for
research on genetic lines. The outstanding problem is that of
the intermingling of the races. It is customarj^ to thrust it
aside as a matter that had best be left to settle itself, and it
may be so; but it is most important. Whether we like it or
not, it is a fact, and I feel sure we would be surprised if the
rate of intermingling could be determined. My impression is
that it is proceeding- much more rapidly than we imagine.

From one standpoint the policy might be to let the races
blend as rapidly as possible. The negro, for example, is the
original type in Africa. It is the general impression that he
can withstand the tropical sun better than can the white man,
but the white man has sui)erior mental qualities. x\ssuming
that both premises are correct, if it were a mere question of
animal husbandry, one would not hesitate to blend the types
in the hope of combining the desirable qualities of each in a
new type. The fixation of a tj^pe, however, requires perfect
control over the individuals concerned, so that undesirable units
can be eliminated, but in beings acting on their own free will
this is not possible. The evidence thus far indicates that in
the mass the blending is undesirable, more especially because
of the deterioration in mental qualities.

Primary marriages between races should be heavily
penalised, because it is a crime against both sides — it destroys
them without producing anything as good or better. Eacli
race should have the opportunity of doing the best of which
it is capable, but there should be no intermingling.

The manifest desire of the blend is to be considered white.
This complicates the problem, because it throws the burden
of absorption on the numerically weaker race.

Poverty (and the consequent lack of education) is a
powerful factor in the rapid l^lending of the races. Improved

66 I'RKSIDKNTIAL ADDRESS— SECTION D.

conditions of lionsing-, livelihood and education will exert a
proportionally great influence in keepino- the races pure.
Accurate records are a great consideration in this regard, and
it has occurred to me that in our system of registering births,
marriages and deaths we have an unusually reliable source of
information, provided it can be made available and properly
(dassified. There are, no doubt, gaps in the evidence from the
scientific standpoint, and the sooner any shortcomings along
that line are overcome, the better. I would therefore propose
that a committee of three or more members be appointed to
take the M-hole subject under consideration and report at the
next general meeting.

Big Game.

Civilisation is a merciless eliminating force. It tends to
destroy everj^thing not absolutely necessary for the progress of
the human race and to create monopolies in favour of essentials.
Science is the handmaiden of civilisation in the work of
adapting* conditions entirely to human needs.

In iNTorth America can be witnessed the closing scenes in
the great drama in which the red man, the bison, the
deer, the bear, the opossum and the coon are being* annihilated
in favour of the introduced types — the white man and the
negro, the horse, the cow, the pig, the sheep, the goat and
the hen.

In Africa the same process is being repeated. Although
published long ago, before anyone dreamed of a " big
game " problem in' Africa, the accompanying illustration
(Plate XXIX) makes it easy for one to imagine all
the principal types in conference over the possibilities of
annihilation at no distant date, and the zebra and
the gnu appear to have suddenly made up their minds
to escape the clutches of fate if they can. Why are they
all in danger of annihilation ? Simply because they are
apparently not essential to the welfare of man. Xot only
that, tliej' are a positive source of danger from the standpoint
of diseases that can be transmitted to liuman beings. Fnder
such circumstances, viewed dispassionately, it seems inevitable
that, however much one would like to preserve them, the
African types, with the possible exception of the ostrich, will
have to give yvaj in favour of the same domestic types that are
now everywhere dominant in Eiir()i)e and America.

I feel constrained, however, to nttei- a word of warning.
These old types have survived all the vicissitudes of the ages,
and even now the chief charge against them is that they are the
natural reservoirs of pests and diseases under whose onslaught
we perish. Does it not seem lilv'ely that thorough research on the
reaction between the original tvpes and the pests and diseases
may lead to important discoveries on the question of immunity
or resistance? They may carry with them an inroortant secret
which, discovered before it is too Inte. mav be immensely
valuable in connection with other problems. While the process
of elimination is going on we should mnke sure that valuable
evidence does not disappear. If possible, colonies of all types

PEESIDENTIAL ADDRESS SECTION 1). 67

slioiild be preserved under conditions which will not permit of
their being a source of hindrance or danger to human beings.

( )n the Value of Zoological Illustrations in School and
Popular Books.

Over forty years ago a scientifically illustrated school
geography was publislied in the United States. Fortunately
tor me, a copy tell into my hands, and from it I gained, not
only a vivid, but a correct impression of the zoological features
of physical Africa. In the accompanying reproduction of the
page relating to Africa (Plate XXIX) the outstanding types
are grouped around descriptive matter in a way that could not
but serve as a wholesome stimulant to the imagination and
inspire a desire to know more about the animals and the country
in which they live. As an illustration, it is quite the best
thing' that has ever come to my notice in a school book. I deem
it worthy of reproduction because it gives a good idea of many
of the animals whose fate is at stake in our " big game "
problem, and also because it may be helpful to those who
have the responsibility of pre]Kiring school books. It is often
through a medium like this that a love for knowledge for its
own sake is inspired. Animal life makes a powerful ai)peal to
young and old alike, and illustrations should be used to the
utmost to enliven what may otberwise be dull and
uninteresting subjects — zoology and geography.

In this connection, I would plead for greater regard for
tiuth in illustrating children's picture books, which are
published in such lavish fashion. Pictures of animals
distorted into impossible attitudes, arrayed like human as well
as other kinds of beings and attempting the weirdest i)ossible
pranks, are too often the rule. In some instances there is no
doubt a lack of exact knowledge on the part of the artist, and
an appeal to the ridiculous provides an easy way to disguise
superficial knowledge and turn it to commercial advantage.
The life story of any given animal is sutficiently fascinating
without fictitious embellishment. It is a great pity that a
child's first impression shoidd be misleading. At the same
time, it must be admitted that works of reference containiiig'
reliable data to which artistically-inclined persons can turn for
exact information are seldom available except in university
and tecdmical libraries. Furthermore, the details of the life
story of most of our wild animals have never been recorded
anywhere. How many here to-day can. describe the develop-
ment of the rhinoceros or the liiDDopotarnus or the sriraffe from
birth to maturity? Every facility should be given for the
illustration and jniblication of observed facts concerning
animal life, more especially of such types as are in danger of
becoming" extinct. The eye should lie appealed to as much as
possible, but the aim should be to give correct impressions,
and thereby avoid the worse than waste due to a misapplica-
tion of artistic ability. The author of my favourite plate
certainly reflects the touch of inspiration, for not only are
the animals faithftdly depicted, but the pyramid and tlie ruin
stimulate speculation in regard to the secrets of the past, and

68 PRESIDENTIAL ADDRESS SECTION D.

tlie rising' sun — shall we say of modern science ? — bespeaks the
beginning of a ncAv era for

The Dark Contixext.

In ihe expansion of civilisation under tlie influence of
Christian ideals, the outstanding- fact is that the trend was
north-westward into Europe, where it gradually gained force
and in time spread like a tidal wave to the American
continents. In Eussia it subsided, as in a morass, in the great
ag'gregation of widely divergent elements that comprise the
nation, and in Asia it was impeded by the inertia of a people
imbued with the ideals of an older civilisation that had
apparentlj^ reached a state of equilibrium. To the south-west
stretched the great continent of Africa, in which profuse
natural resources were apparently available for the asking,
but for some reason they were left almost in abeyance, save
for the slave trade, which attracted world-wide attention. "Why
did the tide of Western civilisation cross three thousand mil?s
of water and develop the ximerican continents rather than
follow the coast-line of Africa and extend its scope to inland
resources that even now are the admiration of the world? The
query might be answered by saying that it followed the line
of least resistance. But that suggests the further query : "Why
was IN^orth America more easily mastered than Africa?

XoRTii America axd Africa Comrared.

In North America the virile races of Europe found a native
race which, though virile in many ways, was not capable of
adapting itself to new conditions, and hence it disappeared
and left the new arrivals free to develop to the fullest extent.
Besides a great expanse of fertile soil and an invigorating
climate, regular seasons and adequate rainfall, natural
resources in the form of water-power, forests, coal, iron and
oil, not to mention gold and silver, were easily available.
It was inevitable that, under the combined attack of the best
races of Europe, inspired by high ideals, such a continent
should confe under control rapidly.

In Africa the same European races attempted the conquest
of the continent, but in i)lace of it becoming an asset, it proved
to be almost a barrier thrust into the ocean to hamper com-
munioation between east and west. "Why did they not boldly
invade and hold the continent in place of going around it for
generations, or, at best, holding on precariously at certain
points ?

In comparison with Xorth America, the natural resources
of Africa were not easily available on account of natural
obstacles — great desert b'^lts in certain parts contrasted wit!i
great swamps and jungles in others: irregular rainfall,
resulting in floods, followed by droughts and scarcity of food
for the millions of natives that were ever present and capable
of adapting themselves to new conditions ; in geneial, a
"climate " that had ('and still hns) a great reputation for
beinff '"deadlv." Fnder such conditions it seems inevitable

PRESIDENTIAL ADUEESS SECTIOX D. 69

that progress would be slow. But if we accept the evidence of
ancient workings tor the recovery of gold and of the ruins
still in existence in the area where we have the pleasure of
holding our meeting to-da}', the attacking forces overcame
obstacles, jienetrated far inland and luade determined efforts
to master the countrj^ Why did they not persist ? The deserts,
the swamps, the mountains and the rivers were gradually
crossed and recrossed, but the " deadh' climate " remained
inscrutable till the jjrogress of science at last shed a flood of
light on the whole matter by proving that its deadliness was
not due to conditions in general, but to the presence of certain
definite destructive agencies. In the light of our present
knowledge there is no reason to doubt that these agencies have
been present in their natural African reservoirs since time
immemorial, and that they were largely responsible for
impeding the progress of civilisation on the continent as a
whole. It is my purpose on this occasion to call attention in
broad outline to certain factors in the development of South
African resources, in the hope of stimulating discussion on the
advancement of scientific research in connection hereM'ith, for
it is apparent that Africa is destined not to yield except to
the pressure resulting from the application of the combined
experience gained by scientific workers throughout the world.
In coping with Africa, one maj" well ask whether the strongest
is strong enough.

Entomological Research ix its Relation to
Human Welfare.

Human Diseases.

It is only necessary to mention the alliance between
sleeping sickness and the tsetse fly ; malaria and yellow fever
and the mosc^uitoes ; typhus fever and the louse; typhoid,
dysentery and other diseases and the house fly, to impress even
the most sluggish intellect with the fact that there is great
need for thorough research into the question of human
diseases and the agencies tliat disseminate them.

Independent of any question of the transmission of disease,
there are two insect.s — the louse (Pediculus humanus) and the
bedbug (Cinie.r lerfulaiia) — that deserve special attention on
account of their influence on the efficiency of labour.

No liuman being can rest properly under an infestation of
either lice or bedbugs, or both, and it seems reasonable to
suppose that the disturbance will be reflected in working
capacity and be in direct proportion to the degree of infesta-
tion. I have frequently received requests for help in com-
bating either one or both of these pests, and the degree of
infestation found on careful inspection surpasses imagination.
It is no uncommon thing to find Kaffirs sleeping on the ground
in the open air rather than brave the swarms of bedbugs in
the huts or barrncks. Cattle and sheep are dipped for ticks
and scab '' because it pays." I submit that it will also pay
in the increased efficiency of labour to fumigate the clothing
and the sleeping quarters of the lower classes witli prus^ic

70 PKESIDEXTIAL ADDRESS SECTION ]).

acid for the destiiiction ot lice and bedbug's. The State owes
it to itself as well as to the poor people concerned to see that
such an easy means of control is adopted.

AuiniaJ Diseases: .

Animal diseases such as East Coast Fever, nagana and
horse sickness — especially tlie latter, wliich for over a quarter
of a century has baffled every effort to determine its natural
transmission — serve to illustrate the need for research alono-
that line.

Ageicultural Pests.
Maize Insects.

While reviewing- the subject of maize insects recently,
I was impressed with the fact that prior to 1900 comparatively
little interest was taken in the pests that attack maize. The
only explanation that I can sugg-est is that maize did not always
hold its present important position in South Africa.

Twenty-five years ago, for example, there was no export
trade in maize, and hence the supply no doubt often exceeded
the demand. TTnder those circumstances insect injury would
be passed over as of little consequence. The live stock
industry, which now makes heavy demands on the maize
crop, was languishing- under tlie burden of rinderpest, lung-
sickness, horse sickness, sheep scab and tick-borne diseases—
redwater, heartwater, East Coast Fever. Locusts made
periodic inroads, and on account of their spectacular nature
attracted i)()pular attention everywhere. In fruit-growing
districts and in the towns the Australian bug (Iceri/a 2nirchasi)
caused a great outcry, and the grape Phylloxera even brought
about a change of Government. In the midst of plagues that
caused such violent political as well as economic upheavals,
the insect pests of maize must have seemed such modest
creatures that they were passed by as not worth notice.

Vahie of Maize in S^outli Africa. — Some idea of tlie value
of the maize crop in South Africa can be gained from tlie
following' official Crop Report Estimates : —

1910 ..

• (C

ensus taken

1911) .

.. 8,()32,r)i(i

niuids

1911 ..

Estimal

.. 8,482.700

1912 ..

do.

.. 8,121.200

. .

1913 ..

do.

.. 8.000.000

J J

1914 ..

do.

.. 8,512,800

1915 ..

do.

.. 10,250,000

1916 ..

do.

.. 8.500.000

1917 ..

do.

.. 11.800.000

191S ..

do.

.. 9.000.000

The total vield for the nine (9) years was

therefore \ 81,898.716 muids.

ond the total value, at 9s. ])er niuid, was £86,854,422.

The average annual vield was 9.099,857 muids. Avliicli,
at 9s. permuid, amounted to £4,094,935.

PEKSIDIONTFAL ADDEKSS SKCTIOX II. 71

Aiinval Loss Due to Certain Maize Fests. — Of the insects
tluit attack growiiii>- maize in South Africa, the stalk borer,
the cut worms (nea? rehitives of the preceding-), the ear worm
{Chloridea ohsoleta), the black beetle {Heteroiiijchus arator),
and the snout beetle [Strophosonins amplicolUs Fhr.), are the
ones of outstanding- importance from year to year. It is
impossible to g-ive an exact statement of the actual loss caused
by these insects because of the difficulty in getting- accurate
statistical records, but all available information warrants my
estimating- that there is a total annual loss of at least 25 per
cent, for the few pests mentioned.* The average annual
3"ield of over nine million muids is tlierefore only 75 per cent,
of what it would be if it were not for the insects. Hence the
total loss may be calculated as 3,000,000 muids, which, at
9s., amounts to £1,350,000, of which stalk borer alone is
responsible for 1,200,000 muids, valued at £'540,000. _ At this
rate, if insect injur j- to maize could be eliminated, it would,
in two years' time, reimburse the country- for the cost of the
proposed elevators for handling- the grain crops of the Fnion.

The loss, though great in the aggregate, is distributed
more or less evenly over the farms in the maize-growing
districts, and hence the nation little realises the extent of the
burden. The loss is virtually an indirect tax levied on tlie
public through the farmers. The farmers would certainly be
up in arms if the Government proposed to raise such an amount
by special tax on the land employed in the production of
maize, and yet the stalk borer and a few other insects inflict
the burden annually while many farmers remain indifferent to
the situation. Under the circumstances, it is highly
important to inquire what can be done to prevent so great
an annual loss. The only sound proposition is to urge the
endowment of research and demonstration work on the full
economic possibilities of the crop as a whole, so that all factors
entering into the production of tlie crop can be elucidated and
the information brought home to those who are in position to
make use of it.

Wheat Inserts.

On account of its intimate relationship to human welfare,
wheat occupies a unique position in the list of cultivated plants.
Anything that touches wheat is at once a factor of world-wide
importance. All over the world some of the most difficult insect
problems centre around this important crop. In South Africa
the wheat louse {Toxoptera gramininn) undoubtedly deserves
first place from the practical standpoint. In the coastal belt
of the Eastern Province a black sheep amongst the ladybirds
(Coccinellidsp), EpiJaclma siniilis, is a serious pest at times.

In the Western Province, Hemiptera, especially Blissus
cliplopterus Dist., often do far more damage than is frequently
supposed. In all cases a solutir)n depends on thorough research
work.

* For detailed information, see Official Report on the. Maize Stalk
Borer (1920), by C. W. Mally, Senior Entomologist, Union Department
of Ao;riculture.

1^ PEESIDKNTIAL ADDRESS SECTIOX D.

Olive Insects.

In view of tlie highly favourable natural conditions, South
Africa should have the finest olive groves in the world, but
there are two little insects that serve as effectual deterrents —
the Ulive Tingid'id, Teleonemia australis Dist., and the
Chrysomelid, Fseudococcinella sewvittata Chevr. When it bas
been demonstrated that the control of these two species by
either spraying- or fumigation falls within practical limits,
olive culture should go ahead by leaps and bounds.

Other Species of Importance.

To continue with even a brief survey of outstanding
problems, would recjuire an undue amount of time; but even
so, attention must be called to the fact that the vine has its
mealybug, every tree and busli its scale insects, the wattle its
bagv.-orm, and the veld its termites. All are replete with
scientific as Avell as economic interest,

Fluctnotions in Relative Abundance of Insects.

Xo insect species is uniformly abundant from year to year.
Some fluctuate far more than others. The American Army
Worm, Leucania unipuncta, and the South African Mystery
Worm, Laphijgma exempta, are species in which extreme
fluctuations occur, a season or two of extraordinary abundance
being followed by a series of seasons of almost total absence
and then a sudden increase to excessive abundance again. With
other species the fluctuations are not so violent, but they are
fairly well marked. Unfortunately there is no really satisfac-
tory way of explaining them. One thinks at once of natural
enemies in the form of parasitic insects, diseases and unseason-
able weather. Climatic conditions coupled with excessi^^e
abundance may possibly affect the vitality of any given species,
which after a time resumes full vitality and makes its influence
felt accordingly. Variations in farm practice may help or
hinder a species. It is highly desirable to determine the exact
causes of these fluctuations, for through the knowledge we may
find a clue to easy coiitrol measure.

Beneficial Insects.

Beneficial insects are important factors in human welfare.
Whether concerned in the production of human food in the
form of honey and the distribution of pollen to ensure the
cross fertilisation of flowers, or whether they are acting as
internal parasites or external enemies of injurious insects, they
are all contributing their share towards making and keeping
the earth a fit place for human beings. Although a few species
are fairly well understood, the great majority of named species
mean little more than names to us. In fact, we have scarcely
touched the fringe of the great problem of parasitism and the
possibility of controlling injurious species by means of their
natural enemies. This phase of entomological work will
increase in importance as the increase in population necessitates
the utmost economy in the production of food. The study of

PRESIDENTIAL ADDRESS SECTION D. ( J

insect parasitism is slow and tedious, and lience no time should
be lost in doing- the utmost possible to perfect our knowledge
along that line.

Eesults Achieved.

Thus i'ar attention has been paid t-o unsolved problems;
but lest someone get the impression that no results of practical
value have been achieved, I shall emphasise the fact that certain
problems have been brought to the point where control is
possible. The elucidation of the life cycle and economy of the
bont tick in its relation to the disease known as lieartwater in
sheep and g'oats and cattle has made it possible for the merino
sheep and the Angora goat to be brought back to the farms
which farmers left in despair 25 or 30 years ago. A detailed
knowledge of the ticks concerned in the transmission of East
Coast Fever in cattle has made it possible to prevent the disease
sweeping like a blight over the stock-raising areas.

At one time the wine and grape industry was threatened
with extinction from the g-rape Phylloxera, but the discovery
of a resistant stock saved the situation. The Australian bug
threatened the life of the citrus industry and a wide range of
other plants as well, but the introduction of its natural enemy
{Novius cardinalis) turned failure into success. The peach
trees were smothered with white scale (Diaspis pentagona)
and the prune industry languished under the burden of the
Bryobia mite, till a critical study of the old California lime-
sulphur-salt wash showed the polysulphides to be the essential
ingredients. As a result, we now have an almost perfect insecti-
cide in commercial form, not only for the tree pests named,
but for sheep scab as well. The fruit fly was thought to be of
such importance that one farmer declared that if anyone found
a way to control it, he would write his name in gold all over
South Africa! A means of control was found in due course,
and the fruit-growers have received ample returns in golden
sovereigns; but the golden promise has been all but forgotten.
Through the use of arsenite of soda, locusts, which once held
sway, no longer hatch and feed and take wing at will in swarms
to darken the heavens like an emblem of Divine displeasure to
inspire the timid with fear.

Let it not be imagined that because I used the expression
" results achieved " I consider that there is nothing more to
be done. Far from it I The true position is that we have
readied a stage where we can control certain pests to advantage.
Still more effir-ient means no doubt await discovery or applica-
tion to present conditions. As hinted in an earlier jiaragraph,
the sun is only rising. For 25 or 30 years we have been using
i:)russic acid (hydrocyanic acid gas) for the destruction of insect
jiests by fumigation, and the process seemed practically perfect.
Circumstances arose which indicated the possibility of improve-
ment, and a search through the literature revealed the fact that
at the beginning of last century it was demonstrated that the
gas could be reduced to liquid form by cooling. The applica-
tion of this to modern conditions has revolutionised fumigation
and placed it on a more nearly scientific basis.

<4 rRESIDK^TIAL ADDKESS SKCTIOX D.

As luiglit be ex])ecte{]. Africa preseJits exceptional diffi-
culties, but we are not without hope of ultimate success.

The Seceet ov Success.

The portions of the virile races of Europe that attempted
the conquest of Africa were held at bay. No blame attaches
to them. Un the contrary, all honour to them, for the wonder
is that they were able to hold out till Science could come to
their aid.

There is no gainsaying^ the fact that on the whole success
has been achieved through scientihc research, not by the pro-
verbial man in the street, but by meu from foreign countries
who, through years of study in institutions of learning, had
acquired special knowledge and responded to the call of Africa,
and applied themselves whole-heartedly to the task of over-
coming- what seemed like insuperable difficulties in the way
of progress.

A Plea eor the Endowment of Educational Institutions.

The knowledge requisite for the solution of scientific
problems does not come from nothing. It is a gradual accumu-
lation in storehouses that we designate schools; colleges and
universities. It is these institutions, inspired with a love of
knowledge for its own sake, that we have to thank for tlie men
who can go forth and grapple successfully with the unknown.
These institutions must be made the centre of our national life,
and the view must be broad so as to prevent the narrowness
peculiar to those of limited outlook. Our young men and women
must be given a fair chance to prove themselves. Thus far tlieir
record stimulates a feeling of pride, and we may confidently
look forward to tlie day when they will hold their own, not
only in this country, but also m an international exchange
of men.

Such being the case, I submit that it is only the part of
wisdom to make every possible provision in the form of endow-
ment for our educational institutions, so as to secure the highest
possible efficiency in training those who show that they have
ability. Our system of education should be like a huge net, in
which every young person is caught up and brought within
reach of the lines of force of the university magnet. Eest
assured, the ear of the teacher will not fail to hear the " click
when young men and women strike the lines of work that appeal
to them. Then is the time when special encouragement in the
form of scholarships should be available, in order that no case
of real merit need recede into obscurity for lack of means to
continue to the stage of national usefulness.

South Africa should invest heavily m scientific research,
for that is the only w^ay we can hope to hold our own against
nations with easier conditions. The more difficult the work,
the stronger and better trained must be the men. _ Thorough-
ness of preparation, even though extra time is required, shonld
be encouraged by the prospect of adequate remuneration when
work on practical problems is undertaken, iind yet university

S.A. JOURNAT, OF SCIENCE, VOL. XVII.

PLATE XXIX.

^^Mi^ffi^

PHYSICAL AFRICA ^) t,

CVII.

DESCRIPTION

1 Afnca contTins ibout one half of a I the
inncl in tlie Torrid Zone It has a laiger pre
1^01 tion of plateau surface more unbioken
coasts a hotter and dr^er chmate moie Cvten
si\e dcseits and more numeious- and gigantic
aniimls than any other of the si\ continents
It also has a gi eater numbei of baibanan in
habitants than all the rest of the world togethei

Tlic northern tiopc piSbCb thro ,li the cei tre of tlie
Greit Debert i d the southern tropii. tl ro gh the
kilah n Desert Between these dcbTt belts is a
broid ft-rtile r<.gion most of it being deluged with
tropical rains during se\eMl months of the jeir
This belt contains the greater part of the population
and of the vegetable and animal life. A smiUer
fertile belt is found in the Atlas region, and another
in Cape Colony. The Great Karroo, in the south
ern belt, is a low plateau, similar in character to thi
llanos and pampas of South America. The conli
nent has therefore five parallel physical belts, three
of them broad tracts of fertile land, and two inter/
mediate ones of desert.

2. Surface. — Nearly the whole surface con m1
sists of broad, low plateaus The edges of the -
continent are partly bordered and its surface _^if
broken by short mountain ranges. ^*^

The highcbt plateau is that of .Abyssinia, The longest
mountain ranges lie along the eastern coast. These
niountams contain the snow-covered peaks K
\jaro and Kenia, the highest in Africa. The ,\lhs ss
Mountains, near the Mediterranean, and (lie Kong ■^JV
near the Gulf of Guinea, are llie only other impomnt ^
r.inges

^. A narrow strip of lowland extends
tween the mountain borders and the coasts and

Pa.ee from " H;irper's School (iei)^i;ipliy." Piihlished in ['.S.A. in 1876.
(Considenihly reduced.)

PRESIDENTIAL ADDRESS SECTION D. 75

training' is not everything. " Tliougli you bray a fool witli
wheat m a mortar with a pestle, yet will not his foolishness
depart from him." Eather have an untrained man with ability
than a fool with a degree. In this connection we must recognise
three classes of men : (1) the self-made man ; (2) the university-
made man; (3) the university man-made man. A generation
ago the self-made man in science could still be found, but
to-day he is a rare specimen. The vast majority of those who
pass as such come under the influence of trained men, from
whom they learn and in course of time become proficient and
achieve well-merited recognition. But the indispensable
nucleus is the man who has come under the sway of our institu-
tions of learning and has a thorough grasp of the problems of
the day. A certain number of untrained men can be absorbed,
but })e it not overlooked that they are a side-draft on the load
until such time as they become efficient. Increase their
number, and the inevitable result is to reduce both speed and
efficiency and to discourage the men who have spent time and
means in preliminary training. That is all the^more reason
why facilities should be available to enable the man of great
natural ability to be trained and thrown into action without
the exhausting struggle against odds for years. The probabili-
ties are that whatever success he achieves in his own strength
will be small in comparison with what he could have done had
proper facilities been available for hini in his younger days.
'No system of education can create ability, but it does enable
each man to do the best that is possible for him. The outstand-
ing man becomes more outstanding and the average man who
otherwise would never be heard of at all is made available for
a wider field of usefulness.

Ample financial means exist to enable every man or woman
of every race to attain his or her limit of achievement, but the
difficulty is to arouse such a thoroug-h popular interest in the
national welfare that they will be made available.

In the past progress has been slow because it has depended
on the devoted few. If progress is to be more rapid in future.
South Africa must endow its schools, colleges and universities
more liberally and see to it that conditions are such as to attract
able men and women to its service.

I am sure you will all agree that thus far science has done
much for South Africa. It remains to be seen what South
Africa, in its own interests, will do for science.

76 rR]:SIDENTIAL ADDEESS SECTIOX E.

THE MAGIC COXCEPTIOX OF XATURE AMONGST

BAXTFS.

Bv Rev. Hexri A. Jrx

OD.

Presidential Address to Section E, delirered Jnhj 15, 1920.

When I was asked to be President of Section E of this
Association, an ideal of a Presidential Address rose before
me. It should, in my opinion, have as an object at least
the opening- of new ways to anthropological research. Bnt in
my position, living on the veld, far aAvay from any library,
without books and reviews as aids, the ideal could not be
attained; so I simply consulted my experiences of thirty years
with South African natives to see if I could not draw from
these experiences some remarks which mig'ht be useful to
others. I think that I found what I wanted, and this will
be my modest contribution to the solution of the, as yet,
unsolved problem of South Africa — the native question.

The coexistence of the Eui'oi^ean Aryan race with the
Bantu race in South Africa has created a situation which
certainly has its advantag'es, but which is fraught with many
dangers. Whatever the future may be, there is no doubt
that for the present the white race has to rule and guide the
black race. I think that we have courageously undertaken
that task — perhaps more heartily than natives themselves
should wish. But I A^enture to put the question : Are we
really and deeply influencing our black fellow-citizens? Are
there not insuperable difficulties in the way ?

Considering first the religious domain, I dare to state
that the influence is real, and it is spreading rapidly. The
Bantu has a strong religious disposition, and the ancestor
worship which he practises affords little relief to his soul,
which longs for life and happiness. The Christian God very
easily supplants the ancestor god in his prayers. Even if
he does not accept him, he rarely makes objections to his
existence. The " Father Who is in Heaven " possesses all
the g'ood features of the ancestor god, and a good many
others, and he asserts himself at once as superior to the
spirits of the deceased forefathers. The Christian religion is
boimd to conquer the Bantu in a comparatively short time.

That is not to say that people emerging from the
mists of Animism can at once grasp the full meaning of
Christianity. We must always remember that the Bantu
creed does not establish any connection between religion and
morality, whilst Christianitv, at least imder its pure form,
is essentially a moral religion. It often happens that con-
verted natives pretend to enjov religioxis privileges and
cultivate religious emotions without leading the p\ire life
which Christianity asks from its ade]its. On accoimt of this
disposition, those who conduct native churches have to be

TRESIDEXTIAL ADDEESS SECTION E. 77

constantly on the watch lest the high teaching of the Christian
religion becomes deteriorated amongst them. i"et mission-
aries, as a rule, believe in the conversion of the Bantu tribes.
They feel that their message has obtained a real hold on
thousands of natives, and this is perhaps the reason Avhy they
are more sympathetic to natives than any section of the white
poi^ulation.

But the predication of a new and higher religion is not
the only duty of the white race towards the black one. The
white man has to rule and to educate the native population;
he must consequently exert a considerable amount of authority
over it. I will not dwell on the political side of the question.
It may be asked to what extent the staff of the Xative Affairs
Department really controls and influences the natives. They
obey. They cannot help obeying, because they have been
conquered. Is the sovereignty of the European acce])ted with
a contented heart? I am not quite sure of it, and I think
that even in the most loyal natives, in the bflckgroimd of
their brains or in the bottom of their hearts, there always
remains the dream of a Bantu Xapoleon who. will appear some
day and reconquer the land of their fathers for them. This
is a burning question. I may only state that in late years
criticism of white methods of government has been more and
more prevalent, and one thing is sure — the treatment of
natives, politically speaking, must be fair and as liberal as
possible if we want to preserve the peace of the land.

I prefer speaking of things I know better, and Avhich are
not so dangerous to discuss. To what extent do natives
submit themselves to the authority of those persons who try
to guide them in a totally disinterested manner — for instance,
missionaries at the head of native congregations or principals
of native institutions? I leave aside the case of employers on
purpose, in order to make the demonstration more convincing.

Let us be just. Our authority, which is purely moral,
which does not rest on any external constraint, which is not
backed by any material sanction, is generally well accepted
by our converts or by our jjupils. However, one must be very
cautious if one intends to be obeyed. The white master will
be wise if he presents his decisions under the sliajjc of advices
rather than of orders, esjiecially if he wants to enforce
anything new, not yet consecrated by custom. He huist also
be careful not to trespass uiJon the native laws of " etiquette,"
and amongst them the law of " tibisa," viz., of giving official
information in due time. Should you put a decision into
execution without having fully explained all the matter to
your natives, jou are sui'e to meet with trouble. These
exigencies, after all, can be accepted by the white master,
however tedious and useless they may sometimes seem to him.
They are part of a sound and sane native policy. Let us
respect the peculiarities of the native mind, as long as there
is nothing really wrong in them.

But cases will happen when, though you have observed
all the rules of their parliamentary etiquette, your boys will

78 PRKSIDK>TIAL ADDRESS — SECTION E.

refuse to obey. Thougli yoiu oiders are perfectly reasonable,
in full agreement with the principles your jinpils themselves
profess, they will not accept them. How is it possible? Some
of them, probably those who are less commendable, are
opposing your will, and they have taken hold of the others ;
the whole class now forms one body, and it will begin to fight.
You may say that such a rejection of authority may happen
everywhere, amongst all the races. But here is the peculiarity
of the Bantu — as they are all agreeing, they are convinced
that they are right. You may appeal to tlieir reason, to their
conscience. Xo avail ! The fact that they are all of one mind
is for them a sufficient justification of the position they have
taken. This is very curious, and evidently comes from the
habits of their former tribal life.

How is a decision taken in the courts of Bantu chiefs ?
There is much discussion first. Everybody has the right of
explaining his thought. The Bantu court is eminently demo-
cratic in this respect. Little by little a general opinion fonns
itself, and when it becomes preponderant the chief " cuts
the matter," as they say, according to the feeling of the
majority. There is no voting, no minority. Nobody, after
the chief has spoken, would dare to think that he may be
Avrong in submitting himself to the dictum of the assembly.
There is no such a thing- as scruples of conscience or faint
ideas that the decision may not be in harmony with moral
principles or with divine will. The horizon of the Bantu mind
does not reach such distant spheres.

1 am sure that this is the psychical explanation of the
difiiculties we often meet in guiding our native pupils, and it
accounts for the terrible acts of insubordination which we
sometimes have to deplore. This shows that a good deal of
supplementary education is wanted to elevate the Bantu mind
from the juridical conception of good and evil to the spiritual
notion of morality taught by the Christian religion.

The best plan to adopt in such circumstances is to try
to persuade one or two of the better boys — ^to awake tlieir
sense of duty. This is very difficult, as it appears to them
that by yielding they woidd be traitors to the common caiise.
However, one may occasionally succeed, and then the resist-
ance will fall at once. I remember one day having reached
that aim. The pupils of the institution wanted the programme
of the school to be amended according to their wishes, and
their demand was not altogether unreasonable. But I had
to tell them that such a change could not be made by myself,
but only by the conference of missionaries which controlled
the institution and was alone competent to decide the case,
to the exclusion of anybody else. But they insisted that they
should be satisfied immediately. They were threatened with
expulsion, but they were prepared for that extremity, and
already were going to pack their little luggage. One of them,
however, began to see that they were decidedly wrong, and
he agreed to stay and to accept the postponement of the
decision. This secession broke the strength of all the others.

PEESIDEXTIAL ADDRESS SECTIOX E. 79

< )ne of tlie principal oi)poiieiit;> said with a sigh: " I see that
we black people are totally unable to reach our ends. We are
no longer of one mind, thus we are wrong, and we must yield
nnd ask to be forgiven." This boy was one of the best
Christians of the Avhole lot, but a typical Bantu.

But I take a step further, aiid beg to state that the
fundamental difference between the European and the Bantu
mind — the difference which mostly prevents a true under-
standing of the one by the other is this : We Europeans of
the twentieth century possess what I may call the scientific
spirit, whilst Bantus are still plunged in the magic conception
of Nature. This is the proper subject of my address. I enter
now the domain of ethnography, properly speaking. My
preceding' remarks applied to the native who has already been
more or less transformed by our religion and by our schools.
We now consider the raw native Avho has not yet leceived any
education. Needless to say, at this present time the heathen
type is still infinitely more numerous than the Christian
variety.

I say that we Europeans of the twentieth century pretend
to possess the scientific mind. We study phenomena; we
notice that a first phenomenon is followed by another. We
try to discover the relation between them. We perhaps come
to the conclusion that the second is produced by the first.
Applying the category of causality, we then assert that the
first is the cause of the second. But Ave do not hasten to di'aw
the conclusion. We first examine, cross-examine, analyse, and
only when we are sure do we pronomice our judgment as
regards causality. Take, for instance, phthisis. The European
scientist has not been satisfied before he has found that the
lesion in the lungs is connected with a particular microbe,
Avhich enters the human body in such and such a way, and
whose progress is concomitant with the jnogress of the disease
which it causes. Owing to the knoAvledge acciuired by
observation, a scientific treatment of the illness is henceforth
possible.

The Bantu mind proceeds on quite different lines. As i
rule, a Bantu does not bother very much about causes. He
accepts the world as it is, without asking Avho made it and
Avhy things are as they are. However, Avhen ])henomena
make him suffer, he Avants to knoAV where such abnormality
conies from — be it disease, drought or accident — and, having
never inquired scientifically into such phenomena, lie at once
believes that they are produced by spiritual agents like
himself, be they ancestor spirits or spirits of living persons
which possess the power of witchcraft. And uoaa-, when it
becomes imperative to fight against such influences, he resorts
to magic. Magic practices are based on a certain number
of principles which are self-evident to the Bantu and which
dictate most of his acticnis in dealing* Avith disease and
other misfortunes. The most important is the pi-inciple of
similarity, which is at the root of what ethnography calls
" sympathetic magic." As long as two phenomena resemble

80 PEESIDENTIAL ADDRESS ^SECTIOX E.

one another, they react on each other. Like acts on like.
Thus a certain remedy will cure a certain disease if it
resembles it in one way or another.

Let me give some examples, to make clear this magic
mentality of the Bantu as opposed to the scientific mentality of
the modern European.

A magician has had the good luck to discover a crow's
nest full of young. He climbs on the tree, and ties all the
little birds together by their feet. The mother crow, however,
is not at a loss to deliver her progeny. She brings each day
a leaf taken from different trees, and puts it in the nest. The
mag'ician keeps watch. He climbs, looks at the leaf, and
recognises the tree from which it has been taken. He goes
and digs a bit of root from that tree. After a few days he
will have cjuite a bundle of various roots. By that time the
little crows will be free, the string which was binding them
having given way, and the magician will possess a medicine
of first quality. By means of it he will be able to deliver
any patient from any disease or worry tying him. This is
pure magic, magic of the nice kind, as it is intended to help
and to cure — white magic, Ave may say — whilst ])lack magic
is the one which intends to kill by the same proceedings.

Another example is as follows : A Eonga of the clan
Timba, which is the great clan of hippopotami hunters, has
succeeded in throwing an assagai into the back of the huge
black beast. The assagai was tied by a long string to the
nervule of an immense palm leaf. "When the hippopotarnus
was wounded, it at once plunged into the water, the string-
unrolled itself, and the big nervule, similar to a pole
twenty feet long, remained floating on the surfnce, being
dragged along by the beast in its attempt to escape. Now
the real chase would begin, and it would be fraught with many
dangers. At that very moment a messenger is despatched
to the hunter's wife in his village not far from the river.
She is told to go at once and shut herself in the hut. to sit
down and keep perfectly quiet. If she does so, the hippo-
potamus will be easily killed. It will not be too wild, it will
not fight too hard, and soon it will be possible to throAv
another assagai betAveen its nostrils. The animal will be
unable to close them any more, water Avill penetrate the hmgs,
and it will die. This is magic. The quiet demeanour of the
hunter's wife will cause the animal to be qxiiet.

Another examjjle borrowed from the agricultural customs
may be given. Stealing mealies in the gardens is of common
occurrence amongst certain tribes, but it Avill be prevented
in the following way: The small nervules of another palm
tree called " rala " are taken. These nervules are like little
sticks, ancl are very flexible. They are called " tinhlamalala . "
At the extremity oi each of them a knot is made. Then a
snake's skin is sought — I mean an old skin, Avhich the ^snake
has cast. It is burned, a powder is made oiif of it, and the
sticks are smeared with it. Then the sticks are woven
together, and something li"ke a croAvn is made out of them.

PRESIDKXTIAL ADDRESS SECTIOX E. 81

This crown is put on one of the niealie stalks. Now, should
a thief enter the garden, these tinhlamalala sticks will all be
transformed into the kind of snakes which also bear that
name of tinhlamalala. They will anorily attack the intruder,
who will fly and throw away the cobs he has already stolen.
Notice here a double similarity which makes the remedy al]
the more effective — the similarity of form — the slender
nervnles with a knot at their extremity resemble a snake with
its head, and the similarity of name — both the nervules and
the snakes are called by the same name, tinhlamalala.

All nonsense I every reasonable person will say. This
will never hajipen, of course. But that is not the question.
The imijortant thing- is that the native will believe it at once,
as the story is quite on the lines of those magic principles
which are evident, unquestionable to his mind.

Hundreds of cases like these migdit be quoted. The life
of the Bantu is full of magic. It is at the base of all his
pharmacoptea, of most of his hunting" and agricultural
customs; it mixes with his religion. But nowhere does the
power of these magic principles appear more plainly than in
the well-known custom of

Boxi: TiirowixCt.

I have devoted considerable time to the study of that
practice amongst the Thongas, and found that it is impossible
to exaggerate its importance in the social, moral and religious
life of the natives. The throwing of bones — hlahluba in
Thonga, timgula in Venda — is both a splendid illustration of
magic, as it is entirely based on the principle of similarity,
and the most elaborate product of the magic instinct.

Amongst tribes of the Suto group the divinatory bones
are mainly four in number, being four bits of carved ivory or
bone, two male and two female. Amongst Zulus and Thongas
the bones are mostly astragalus bones taken from the legs
of different animals, a number of dift'erent objects being
added to them. The famous basket of the bone-thrower, such
as I received from one of my best informants after he had
initiated me into his wonderful art, must be shown. The
contents of the basket are very varied. Sometimes as many
as fifty dift'erent pieces are found in it.

There are hrst the astragalus bones taken from the legs
of domestic or wild animals. According to the law of
similarity or of correspondence, the domestic animaJs will
represent the inhaJ)itanfs of the village, whilst the irilrl
animals represent the various powers and influences of the
hush. Astragali of goats are the most numerous. The he-goat
corresponds to the father, the head of the kraal ; the she-goat
is the mother; the astragalus of a goat which had only one kid
is the y(ning married Avoman; whilst a number of sinall bones
coming from the kids of different ages represent the boys and
girls, weaned or not. The correspondence is perfect. Then
there are the astragali of sheep — these represent the royal
family, as sheep are more valuable and less common than goats.

82 PRESIDENTIAL ADDRESS SECTIOX E.

The cliiei, aiitl queens and their children are all represented by
the various astragali of that domestic animal.

As regards wild animals, sets of different diviners vary
very much. However, one will always find the diiyker, the
grey antelope which steals sweet potatoes in the fields at
night. It represents the wizards, who are also, supposed to
accomplish their bad deeds Avhen it is dark. The wild boar
has many significations. It means the doctor, the medicine
man who digs the earth to find his medicinal roots, as the
]>ig when it searches tlie ground for food with its snout.
It also means the spirits of the deceased, as wild boars are
dwelling in the sacred wood where the ancestors were buried. .
By extension, this astragalus also means the old people who
are soon to be promoted to the dignity of gods. The baboon
represents the permanence of the village, because people say
baboons never move from the cave where they dwell.

The leopard means rich joeople who feast on meat every
day; whilst hyena means the counsellors, all the legion of
fiatterers who follow the chief and eat what he gives them,
the chief himself being the lion and being rejDresented by the
phalanx of one of the toes of the king of animals.

A curious bone in the set of one of my informants was
the astragalus of an imjDala antelope, discovered by him in
the stools of a hyena — a wonderful finding, indeed. It meant
the ancestor god, because the deceased forefather also had
been swallowed by the earth and he reappeared to bless or
to kill.

The malumbi is a special astragalus taken from a little
red anteloj)e, and plays a great part in the set as lepresenting
everything that is violent, which is spreading blood, the
mysterious power of Heaven, the enemies, and occasionally
white people.

Besides these astragali, there are quite a number of other
bones or of various objects in the diviner's basket. Pieces
of the carapace of a tortoise when falling on the favourable
side represent the peace of the village, like a tortoise walking
slowly and comfortably under the rays of the sun; everybody
perspires agreeably.

Sea shells : The Oliva represents male attributes, military
courage ; whilst the Cyprea means the feminine attributes —
IDots, kitchen, baskets, and also pregnancy. AVhen showing
its opening, Cyprea indicates the open mouth, either laughter
or cries.

Two stones of an abnormal form of the fruit of the
nkanye or marula tree represent the vegetable world, trees,
medicines, etc., and one always meets with two or more real
black stones foimd in the stomach of the crocodile (which
is said to swallow one each year). They represent darkness,
misfortune, accident, or the contrary, according to the way
they fall.

These are the principal pieces of the divinatory set. There
are generally two of each kind, one male and one female.
The diviner takes them in his hands, spits on them to give

PRKSIDENTIAL ADDRESS SECTION E. 83

them something of his spirit, and throws them to the ground
on a mat, saying " Mamoo " ! He looks at them intently^
wanting to know what they have revealed. He then begins
to explain what they say, always following the well-known
rnles of interpretation, though he may display a considerable
amount of individual imagination in his explanation.

The astragalus bone can fall in four different ways.
It can show its convex side. This is the positive position,
and in that case the person indicated by the bone is on his
legs, standing, living, healthy, active. If the astragalus falls
in the opposite way, showing its concave face, it is the
negative position, and the person represented by it is on his
back, ill, powerless, dead perhaps. These are the two prin-
cipal positions^ corresponding to the upper face or the lower
face of the bone respectively. But it can also fall and show
its right side, which is slightly inflated. This means that
the chest is fidl, the person indicated is full of anger, or
courage, or hostility. He is like a cat which spits and is
readj^ to tear ; whilst the opposite side, the left side, is called
" minkono," the elbows, and figures a person peacefully
leaning on his elbows in a quiet mood.

The diviner knows the case which has been brought to
him, and he looks to his bones on the mat to see if there is
any correlation between the Avay they fall and the given case.
If not, he will say: " The bones have not spoken; let us try
again." Shoidd they refuse " to speak," he goes to another
place behind the hut, on the square, to try again, till he sees
some correspondence between their disposition and the subject
on which he must give advice or foretell something.

I have published and figured some of these cases in
Volume II of " The Life of a South African Tribe " a910),*
the case of the sick mother, of the Sikororo battle amongst
the Xkuiias, the prophecy of a migration, etc., and I cannot
do more here than refer to those plates and to their inter-
pretation. If my readers care to study them, I am sure they
will confess that this system of divination is marvellously
clever, and quite capable of producing conviction in the mind
of anybody, on one condition at least, viz., if he admits the
magic principles which are at the base of the whole affair.
If really " comparison is reason," if really like acts on like,
then the astragalus of a goat can perfectly represent the fate
of a mother, and the stone of the crocodile predict her fate.

The native is from his birth convinced of the truth of
these principles, and therefore these bones are for him the
most precious guide in life, the great inspirer and the great
helper — his Bible, as one of them told me one day, and more
than the Bible, as he added. He consults them constantly.
Practically no disease is treated, no religious act performed,
no travel undertaken without consultation of bones.

* Copies of this I)ook can l)e obtained from A. W. Bayly & Co.,
Loureu^o Marqvies.

84 PRESIDENTIAL ADDRESS SECTIOX E.

Yet it is easy to see that this practice is highly
detrimental. It paralyses any attempt to use reason or
experience in practical life. It annihilates moral conscience,
as it makes reflection useless. Bones are tliro"vyn. They
reveal the cause as well as the remedy of any disease or
misfortune. There is no need any more to make an effort,
to fight a battle, to employ energy in order to free oneself
from the hardships of life. It can l)e safely asserted that no
real progress in civilisation or morality can be obtained as
long as the basket of the bone-thrower remains the Bible of
the Bantu. But one can go further, and state that, however
picturesque this magic conception of Nature may be, it is not
only a check to progress, but it is decidedly harmful, and
as long as it is still predominant it is impossible for the
European ruler to govern the black race in a satisfactory
manner. There is not only what I called white magic — these
innumerable rites and practices which might be considered
as quite innocent by a superficial observer, and as deserving
only to be laughed at — there is a black magic, namely, rites
performed to injure or to kill, or to attain certain aims by
criminal means.

In the month of January of this year the IS^ative Com-
missioner of Sibasa, Northern Transvaal, put in gaol the son
of the chief, who was found guilty of having killed a man.
When he inquired into the reason of the crime, he found
that it had been accomplished for magic purposes. Ha in was
wanting, and the crop of the year compromised. An intelligent
man who was a particularly good cultivator had been chosen,
probably on the advice of the bones, and murdered. His head
had been cut off and thrown into a mealie pit. Like acts
on like. The wisdom and power of that distinguished native
farmer would in this way spread all through the land, the
gardens would be full of grain just the same as the gardens of
that man, because rain would fall. And, indeed, rain fell —
plenty of rain !

The murderer was arrested, but nobody really thought he
was guilty. When the official tried to inquire into the
opinion of the Ba-Yenda on the subject, he received the
following answer: " The chief's son is a fool. Why did he
not send somebody else to kill that man? " As regards the
murder itself, it was quite legitimate according to the
conscience of the tribe.

I think, therefore, that my conclusion cannot be opposed :
As long as the Bantu is so completely plunged in this magic
conception of Nature, he cannot go ahead, because he is resting
on fallacious ground ; nor can he really be influenced by his
white master. The European and the Bantu are living in two
separate and opposite worlds of thought, and it is impossible
in those circumstances to obtain any true communion of mind
between them.

However, the position is not desperate, because it is
bound to change. Let us remember that our fathers, though
belonging to the so-called superior Aryan race, held con-

PRESIDENTIAL ADDRESS SECTION E. 85

ceptions very similar to those some centuries ago, and that
remnants of those magic practices are still found amongst
the peasantry or the less cultivated portion of the town
population. I was shown in Switzerland some years ago by
a friend belonging to the medical profession the heart of
a goat or of a sheep pierced by at least fifty big" pins Avith
large black heads. This object had been found in the hands
of a woman at la Chaux-de-Fonds, the town of watchmakers —
a very much advanced industrial centre. She had an enemy,
and, in order to cause him pain, she was planting a pin in
the sheep's heart from time to time, being convinced that,
according to the laws of sympathetic magic, the heart of her
enemy would be similarly pierced and made to suffer unbear-
able agony. A number of such practices are still to be found
in all civilised countries.

Education, scientific training-, higher moral and religious
conceptions have delivered most of the Europeans from magic.
The same will certainly hajjpen to the Bantus if they submit
themselves to the teaching brought to them by us, and there
is no doubt that there is amongst them an ever-growing desire
of obtaining instruction. They get it more and more now.

Thus, after so many years of work amongst South African
natives, I do not fear to take a position which some may call
unduly optimistic. The relation between the races may be
difiicult. It will perhaps become very strained, owing to
faults which may be committed on both sides. But I trust
that in the long run the Christian factor and the educational
factor will bring tliem nearer and nearer. Though keeping
apart from each other in many ways — I do not believe in
intermarriages — they will be able to esteem each other and
to reach a fruitful co-operation.

LABOUR CONDITIONS IN SOUTH AFRICA.

By R. A. Leheeldt, B.A., D.Sc.
Professor of Economics, University College, J oluinneshnrg .

Fresidenfial Address to Section F, delirered Juhj IT, 1920.

The racial situation in Soutli Africa is unique — no other
country shows the same combination of white and black, and
no other country offers, from its experience, a ready-made
solution of the racial difficulties that exist there. That is
not to say that the experience of other countries is to be
ignored. Of course, the history of countries in which two
disparate races have to live together should be studied, and
lessons should be drawn from it for the guidance of those who
control South African policy, but nothing like direct copying
is possible.

86 PRESIDKNTIAL ADDRESS SECTIOX F.

South Africa's problem is unique, in the first place,
because of the proportions between the two races. In the
Southern United States there are whites and blacks, but
though the blacks form a niajoritj^ in certain districts, the
situation as a whole is dominated by the presence of an over-
whelming white nation, amongst whom the negroes are a
handful of strangers. Moreover, most of the negroes are of
mixed blood. In South Africa the pure-bred Kaffirs form the
great majority of the population.

On the other hand, such a country as Jamaica contains a
great majority of tlie black race, but there competition practi-
cally does not exist. The wliites are a small ruling class, and
the question who is to do manual labour, if it ever arose, has
long since been answered. In South Africa there is a large
and vigorous white population, partly immigrant, partly
settled for several generations, Avhich shows no sign of dying
out ; the relation between them and the blacks has not yet
reached any condition of stability.

Examples might perhaps be found, if not now, at least
in times past, where a similar numerical relation has
occurred between two A'igorous races, but there is another
condition needed to make anything like a close parallel with
South Africa, and that is a strong resistance to amalgamation
between the two races. In South America, in particular,
there are many interesting racial combinations, but there
little prejudice against intermarriage seems to exist, whereas
both Dutch and English, who make up the bulk of the white
inhabitants of South Africa, are strongly opposed to mixture
with the coloured races. That sentiment, which is not shared
even hj the French in their colonies, has played, and will
play, an important part in the history of the country.

It is when there is a sharp barrier between the races that
the special problem of the " poor whites " or " mean whites "
arises. In every community tliere is a constant vertical
diffusion between classes — children of the fortunate classes
fall below the circumstances of their birth, whilst exceptional
individuals from the mass of the people make their way
upwards to wealth and influence. The process is a natural
and healthy one, but where a colour bar exists diffusion is
interrupted. The children of the superior race, who liave
not the brains nor the luck to maintain themselves in a
superior position, are inhibited by the national sentiment from
making a living by unskilled or low-grade work, as they would
naturally do; they become destitute wliile clinging to the
remains of racial pride; they create a special and embarrassing
problem of poverty that does not exist in a countrv with a
homogeneous population, nor — at least not markedlv — in a
country like Brazil, where intermixture takes place freely.

Nor does the problem of the poor whites stand alone, for
the same conditions prevent tlie more intelligent members of
the inferior rnce from rising. There are in South Africa
natives whose brain power would enable them to do work of
fair quality in administration, in tiie learned professions, and
in business, but they are deprived of educational lielp and

PRESIDENTIAL ADDEES,S SECTION E. 87

are ostracised by sentiment. Indeed, in part of iSouth Africa,
natives hardly aspire to skilled mannal labour; the conse-
quence is a discontent, wliicli grows stronger as the natives
grow more conscious of the situation. I may remind you
of those featiu'es in the history of South Africa which are
most essential in understanding its present circumstances.
The greater part of the Union has been settled by Dutch
farmers, whose ideal was the patriarchal style of living. The
family, practically isolated by distance from its neighbours,
occupied an estate usually some ten square miles in extent,
where they farmed for subsistence — that is, they grew a small
quantity of corn and vegetables for their own use, and allowed
their cattle to graze on the wild pasture around them, yielding
meat and milk. On the rare occasions on which they needed
money, they sold an ox or a cow at some far-off village.

The ideal of life, however, included the bringing up of a
large family, and the land was divided equally between the
children. Thus the kind of farming adopted could at most
only last a few generations. It is being destroyed, not so
much by any external circumstancea — though immigration,
growth of cities and modern improvements in agriculture and
transport all help — as by the mere growth of population. There
are districts where for several generations subdivision of farms
has actually taken place, until the descendants, weakened by
intermarriage, drag out a miserable life on plots of ground
too small to yield them nourislunent ; in those districts there
is much physical and mental degeneracy.

Mostly, however, the usual results of unequal ability show
themselves. The more energetic or lucky son buys out his
brother's shares in the family estate; marriage between land-
owners consolidates property, and in the course of half a
century, perhaps, there comes to be the usual gradation of
Avealth and poverty. A class of small squires becomes estab-
lished, and a large section of the country population becomes
landless and dependent. It is not necessary to haA^e the rule
of primogeniture for this condition to arise; on the contrary,
no legal or social arrangements have yet been invented that
will stop it from arising out of the natural inequality of men.

I shall attempt a classification of the country population
who are more or less poor. It will, of course, be rather vague,
and I can offer no figures to show the extent of any class.
Nothing at all satisfactory in the nature of a census exists.
Statements have been made by Ministers as to the extent of
the poor white problem ; they appear to have been based on
an inquiry through tlie magistrates, but the results of the
inquiry have not been made public, and it seems doubtful
whether it v\-as conducted in a way to secure results of
scientific value.

I should like, however, to refer to the researches of my
colleague. Prof. W. M. Macmillan, who has made a first-
hand investig^ation of conditions in many country districts,
especially in Central Cape Colony. Though a single-handed
inquiry is, of course, quite inadequate to a nation-wide social
problem, and he has had no Governmental assistance, he has

88 PRESIDENTIAL ADDRESS SECTION F.

been able to throw considerable liglit on the problem. The
results, embodied in a course of lectures delivered in Johannes-
burg- earlj^ in 1919, have now been made generally available
by publication in book form.

Macmillan lays stress on the absence of any proper
system of land leases in South Africa. The traditional farmer
is a freeholder, and those who are not fortunate enough to
own land tor their farming often farm on metayage system —
that is, they do not pay a fixed money rent, but share the
produce of the farms with the owners, in certain stipulated
proportions, with no security of tenure beyond the current
season. Such conditions place them entirely at the mercy of
the landowner, and though no doubt a good deal of neigh-
bourly feeling exists, there is no secure tradition of fair
treatment like that which has mitigated in practice the
unsatisfactory features of English land tenure. The conse-
quences are disastrous, for not only are the landless farmers
kept down, but an improvement in agricultural methods is
rendered almost impossible. Returning to the question of
classification, we may distinguish, first, those who own some
land, but too little to afford proper support for a family when
cultivated according to the traditional methods. Xo doubt in
many cases improved agricultural technique would be enough
to make such persons comfortably off, and Government has
done a good deal towards agricultural education. But the
difficulties must not be overlooked. The country folk
ordinarily are very lacking in general education, so that it
is not to be expected tha^t they should take readily to new
ideas, and the customary conservatism of farmers is reinforced,
in South Africa, by the uncertainty of agriculture in that
country. The rewards are great in case of success, but the
risks of plant and stock diseases, of hail, droughts, and so
on, are far worse than in Europe, so that farming is some-
thing- of a gamble.

Innovations backed by the authority of experts have
occasionally, on trial, led only to loss, and though, it is true,
the most conservative farmer sometimes loses his maize crop
and sees his cattle perish of drought, failure on the part of
the expert naturally makes the average countryman sceptical.

Next come the landless class who have to hire land from
their more fortunate neighbours — called " bywoners "
because they live on another man's land. The question that
most urgently concerns tlTem is that of leasehold tenure — as
it is, they usually receive from two-thirds to one-third of the
yield of the ground they cultivate. The proportion varies
according to local custom, and according as the owner or
tenant supplies stock and implements, but I understand that
it is, on the whole, tending downwards, so that the position
of the class is deteriorating. Such tenaut farmers, holding
only for one season, and liable to be sent away at the caprice
of the landowner, cannot be expected to form an enterprising
section of the community.

Thirdly come the agricultural labourers, but they do not,
in practice, form a class distinct from the preceding one. The

PRESIDENTIAL ADDRESS SECTIOX F. 89

bywoner works for wages when lie can, and cultivates a little
giouud ii lie can, and usually does both. What his economic
position is may be judged from the i'act that a customary
rate of wag"es in Cape Colony is three shillings a day — and
that for employment wl/ich is seasonal and often leaves him
for weeks without any wages at all. This class naturally
merges into the next, namely, the destitute.

In this fourth class I niean to include those who are
destitute without suffering from any actual bodilj^ or mental
disability. The poor white problem is essentially concerned
with these ; there is a fringe of poverty due to mental weak-
ness, degenerate bodily features (such as blindness), to
accidental disablement, to old age ; but the core of the problem
is the existence of a mass of persons who are fit to work, but
are unable to do so for what may be summarised as social
reasons. How many persons should be included it is
impossible, at present, to say, but it seems that the bulk of
the destitute country population do not suffer from bodily
disease, except such as is brought on by want and unhj-gienic
conditions, nor from definite mental defects. They constitute,
therefore, a class who might be reclaimed and made into useful
citizens by a suitable policy.

Their disability lies in the fact that they have neither
any training in skilled work nor any habit of work. Their
traditions are those of the easy life of a landowner, with
Kafl&rs to work for him, and they cling to prejudices against
doing what they regard as " Kaffir work " — work which in
England or America is done by white men, but which they
expect to have done for them by servants — a pretension
sufficiently ridiculous on the part of men who can hardly earn
three shillings a day. Too much should not be made of this
prejudice, however; it could no doubt be got over in time; the
most serious defect is the ingrained laziness that goes with it.

The enormous disparity in wages between town and
country tempts this destitute class into the towns, especially
Johannesburg, where they expect to find the streets paved
with gold, but where, of course, their want of skill leaves
them really worse off than before. Some are absorbed into
industry, but many are paupers, and many become the tools
of more actively disreputable and criminal persons, especially
as agents for the illicit sale of liquor to natives — a flourishing
industry on the Rand. Tlie migration is beginning to consti-
tute a serious danger to the State.

The fifth group is that of the invalided and mentally or
physically deg'enerate, who have to be dealt with by the same
methods as in other countries. About them I do not propose
to speak.

Apart from such jiroblems of poverty as are common to
all countries, the policy of the Government has hitherto been
directed almost exclusiA-ely, in the case of rural distress, to
alleviation by means of loans of land, stock or money. There
have been numerous attempts at establishing small rural
colonies, under supervision, and providing capital for the
colonists to start with. The usual result of this is that a

90 PEESIDKXTIAL ADDRESS SECTIOX E.

few settlers make good, aud in the end become substantial
farmers, while the majority linger on for varying periods,
lose all their new capital, and drift back into destitution.
These colonies may be regarded as an experiment which has
yielded some information, but the method is entirely wrong
and the scale of the operations hopelessly inadequate. The
latter point is clear, since the settlers are to be niimbered by
hundreds, while the poor whites of the country have been
estimated officially at something like 100,000. As to the
former point, the root-cause of the destitution to be met is
that the traditional agriculture of the country folk is not
suited to present-day conditions ; to base remedial measures on
it is sure to lead to failure — the poor whites do not know how
to make a living except with a large piece of land. The first
thing needed is to teach them new ways, and to train them
to work harder than they have done. I am glad to say that
the Department of Lands appears to have come round to this
view as a result of this experience.

One settlement deserves special mention^ — that at
Kakamas, on the Orange Eiver. It was instituted by the
Dutch Reformed Church, on the traditional lines, so far as its
economic aspect is concerned, but the authorities of the
Church, owing to the influence they exercise on the Dutch
Africander population, have been able to exert a fatherly
control over the settlers. The result has been favourable — the
settlers have been trained in habits of industry, and the
proportion of successes has been considerably greater than in
the Government colonies. But the history of the settlement,
which is an old one, carries a most important lesson — a new
generation has grown up there, and many of the younger men
are finding themselves in the very situation from which the
colony rescued their parents — that is, there are too many of
them to live on the area available.

It seems plain that the great majority of the destitutes
cannot become successful independent farmers. They must
go through the stage of working for wages, and then better
their status if they are able to. Hence legislative efforts
should aim at training them to be good agricultural labourers
in the first place.

This, however, leads at once to the problem of the rela-
tions between whites and blacks. Wages of white farm
labourers are, as we have seen, miserably low, but in the
opinion of most progressive farmers they are as high as the
labour is worth. IN^atives can be obtained in large numbers
at about the same wage, and it is doubtful which makes the
better workman. The natives are usually more industrious
and, perhaps, more honest; the white man has more latent
ability, and his hope lies in the development of that. Only
quite slow improvement can be looked for, and policy must
be based uuon the liope of Dlacing the children in a better
position. Very little can be done at the best for the majority
of the destitute whites of the present generation, but if their
children can be well trained in favourable circumstances their
racial superiority will show itself, and they may be able to

PKKSIDEXTIAL ADDRESS SECTION F. 91

maiutaiii tliemselves by work of a higher kind than the native
can accomplish.

I say " may be able," for the prospects are far from clear
in any case, and how far the Government is from graspino- the
needs of the situation may be judged from this : It has recently
been felt that no progress could be made unless powers were
obtained to segregate the hopelessly unemployable and send
them to labour colonies under police supervision. A Bill w^as
drafted, and one of its provisions empowered the" Government
to send such persons to labour colonies with their wives and
children ! Is it possible to imagine a more utterly -misdirected
policy than to send children to a penal colony because their
fathers are wastrels y

Policy must be held to include all classes of education,
and the attempts that are being* made to promote general
education in South Africa are creditable, especially in the
Transvaal, but much more might be done, especially with
regard to agricultural and industrial teaching. It is especially
desirable to dispel the notion which the South African
countrj'man holds — that he knows all that there is to be
known about agriculture.

But whilst there is some improvement in this respect, the
natives are not standing still. Their education, except in Cape
Colony, has been shamefully neglected by the Government ;
but they are quick to learn, and so appreciative of education
that they spend money on it themselves. And if they have
not acquired iuuch literary education yet, they get industrial
training from the nature of their work, for they are called
upon to do all kinds of work under the supervision of white
artisans, and so get the opportunity of acquiring skill as
mechanics, builders' workmen, miners, etc. Of my personal
impressions of South Africa, none is more marked than the
advance noticeable among tlie Kaffirs during' the fifteen years
that I have known the- country. Tliey are coming', moreover,
to learn their economic importance, and one feels that it will
not be possible for long to maintain the policy of repression
which the former Republican Government adopted, and which
has not yet been definitely modified.

We are now prepared to discuss, on broader lines, the
future of a country whose population is one-fiftli of European
and four-fifths of Kaffir origin. The present conditions can
only, as we have seen, be looked upon as transitory and
unstable; we may, for the sake of clearer thinking, first make
a list of the ultimate possibilities. These are (1) that the
white race should continue to grow and colonise, and gradu-
ally drive the Kaffir race into other countries ; (2) that the
Kaffirs should advance so much as to create a situation
economically impossible for the whites, gradually driving
away the latter, except for a small governing class such as is
found in India now ; (3) that the two races should be effectively
segregated in different districts of South Africa, and agree to
leave each other alone there ; (4) that they should mix to form
a population which, while not actually homogeneous, would be
divided by no insuperable colour line, but would permit of
free dift'usion between classes.

92 I'EESIDENTIAL ADDRKSS SECTION l".

The first two alternatives may be ruled out. A " White
South Africa '" has been talked a1)out, but as the natives show
no sign of dying out — and, indeed, are increasing fast in
numbers — it coukl only be accomplislied by forcible migration
of some five million natives, which would be outside ail
practical politics. Xor is it to be expected that the emigration
of natives should come about because they could not stand the
economic competition of Europeans — it is much more likely to
be the other way about. But the second alternative is hardly
more likely than the first. The white people already amount
to a nation in numbers and self-consciousness; most of
them were born in the country, and know no other; they
certainlj^ would not give up their country to the Kaffirs
without armed struggles, unless, indeed, they were to find the
conditions of life so difficult for several generations that the
birth-rate dropped almost to zero. Such a suggestion may well
seem absurd when one thinks of the vigorous Africander race
of to-day.

We come then to segregation as a policy that cannot be
dismissed quite so curtly. Nevertheless, to carry it out
effectiveh' would be a heroic policy beyond the power of any
statesman. The natives are so thoroughly incorporated in the
industries of South Africa that to exclude them and rec^uire
them to live in certain districts, while the Europeans lived in
others, would revolutionise the country. The work could not
be carried on without them until a new population of unskilled
labourers had been introduced to take their place, and this
could only be done in opposition to all the immediate interests.
Not only do manufacturers and farmers employ natives, but
the white workmen are used to being supervisors of native
labour. A segregation policy might in the end be to the
collective advantage of the white working classes, but the
immediate effect would almost certainly be a reduction in
wages, since employment would have to be found for so many
more whites. But if nearly all the voters in the country found
that a segregation policy would be contrary to their personal
interests, what chance has it of being carried out, however
beneficial we may think its ultimate consequences would be^

A policy of segregation in a limited way — dealing with
land ownership only — was inaugurated by tlie Government by
a law passed in 1913. Certain areas are set aside in which
only natives may own or lease ground, and they are forbidden
to own or lease ground elsewhere. There is, of course,
nothing to prevent their living elsewhere, as, e.g., the mine
workers do. This law is directed against certain minor evils,
especially the custom of allowing natives to " scjuat *' on farms
that should be thrown open for proper cultivation by European
methods. It may effect some improvements, but there is no
prospect of its leading to any more thorough measure of
segregation ; and it is to be noted that the areas reserved for
natives are scattered throughout tlie country, so tliat their
formation does not constitute a step towards delimiting any
compact region intended to be for white occupants onlv.

If, then, no strenuous attempt at segregation is to be

PRESIDENTIAL ADDRESS SECTIOX E. 93

expected, if the two races are to live side bj- side indefinitely,
racial mixture is, I think, inevitable. In the Transvaal,
Orange Free State and Xatal one is used to the contrast
between European and pure-bred natives, and at first sight
the boundary line seems one that there is neither risk nor
desire of passing, lint in the neighbourhood of Capetown (not
the whole of Cape Colony) there is no pure native population,
but a large proportion of half-castes — the so-called Cape
coloured people. These are useful citizens, who are well liked
in their own neighbourhood, and they tend, to some extent,
to inigTate to the other Provinces ; there is nothing- to keep
them from intermarrying, either with Europeans or with pure-
bred natives. Intermarriage may not be frequent, and it is true
that sentiment amongst the natives themselves is rather
against it. It takes place to some extent all the same, and
the Cape coloured people form a natural bridge between the
two sections of the population. The fact that they came into
existence, despite the strong feeling- against mixture between
the JSTorth European races and the natives, shows how unlikely
it is for the two races to live side by side without mixing.

The population described as " mixed and other coloured "
in the Cape Province grew', between the 1904 and 1911
censuses, by 15 per cent., whilst the total population grew by
6| per cent. In the three northern Provinces, where the
number of coloured people is still small, they grew bj^ 40 per
cent., while the total population grew by 23 per cent.

Where race mixture is frankly accepted, it comes as a
corollary that the humblest-born citizen may aspire, not,
perhaps, to the highest positions, but to an advance that will
usually satisfy him, and the less fortunately endowed members
of the superior race take up unskilled work, no doubt not
willingly, but without incurring the contempt of their own
people. The distinction of classes is like that, let us say, of
Engdand in the eighteenth century, not like that between
conqueror and slaves. In these circumstances, the special poor
white problem, due to the colour bar, does not exist.

If nij forecast of racial mixture in South Africa turns out
to be correct, it will, of course, not happen in our time.
It would take several generations to come about, and the
problems facing the country cannot be left to themselves in
the hope that they will disappear. The Government and people
are no less called upon to take energetic steps to deal with the
abnormal destitution among a large section of the white
inhabitants, as well as to provide the natives with opportunity
for the reasonable progress they are capable of.

Let us gdance at the statistics of population in South
Africa to see what light they may throw on these distant
possibilities. How thin the population is will be realised at
once from the figure of 13 to the square mile, which is the
average density, including all races. Clearly the country is
yet to make.

But a large part of it is very poor agriculturally, having a
small and uncertain rainfall. The western part is often known

04 PEKSID]-:>T1AL ADDRESS SFXTIO>' T.

as desert — the Kalahari — and the central part, known as the
Karroo, though much more fully occupied, is not xevy different
from the farming- point of view; they are both suitable for
grazing, but the number of sheep (n^ cattle that can be safely
carried is small, on account of the risk of drought. It may be
that in time, with the suitable provision for winter feeding
of animals, for deep ploughing and other new methods, the
productiveness of the country will be increased, but it is a
most striking fact that under the S5^stem now in vogue
considerable stretches of Central South Africa are replete with
iuhabitants. Although there are only one or two to the square
niile, not only is there no immigration, but increase in popula-
tion drives some of the inhabitants to emigTate to more fertile
districts in the neighbourhood. The area of the worst poverty
practically coincides with the area in which population fell
off between the censuses of 1904 and 1911. We thus find the
Malthusiau problem in an acute stage in a country far more
thinly peopled than the Highlands of Scotland.

In the Union as a whole, the proportion of whites — about
20 per cent. — showed no perceptible change between 1904 and
1911, the two races increasing at just about the same rate.
However, the registration of natives is not quite complete, and
as oversights were probably less at the later census than at
the earlier, this would make the natives appear to have a some-
what greater rate of increase than they really have. Their
birth-rate is moderately high, and they are a good deal aff'ected
bj' disease ; malaria is endemic, and the diseases that usually
follow contact with Europeans are rife. Still, the native races
are healthy enough to maintain themselves aud progress.
There was no immigration to speak of in the years immediately
preceding the war. The war period was, of course, abnormal,
but in view of the economic situation, and of the steady growth
of nationalist feeling, it does not seem likely that any
considerable emigration from England will take place in the
future — not enough, that is, to aff'ect the racial situation
much. The most important statistical feature, if it turns out
to be more than a temporary fluctuation, is that the white
birth-rate is falliug. In view of the war period, the figures
must be received with caution, but they actually show a fall
from above 32 in 1911 to below 28 per thousand in 1918 and
27 in 1919. A few more years should suffice to show how much
importance is to be attached to these figures. The death-rate
is low, and cannot be reduced much, if at all, further, so the
natural increase of ]3opulation is now tending to be less than
formerly, and it is not supplemented by immigration. Thus
there seems no prospect that South Africa will become any
more " white " than it is at present. If it is to become so, it
can only, I think, be by some deliberate act of policy on a
heroic scale.

If complete racial mixture is to be the future of South
Africa, we might look to Jamaica as an illustration of its fate.
There the whites constitute a small aristocracy, and there are
fifty coloured people for one white. But then the climate of
South Africa is much more favourable for Europeans than that
of Jamaica, so that the analogy breaks down.

PRKSIDKXTIAL ADDRKSS SKCTIOX I'. 95

Climatic considerations suggest a partition of the Union
of South Africa into two regions — one to the east, which is
favourable to the natives, where the European inhabitants are
mostly of English descent, and one to the west more favourable
to white settlement, and where at the present time the country
people are nearh* all of Dutch descent. The suggestion occurs
to one that the one area might be developed as a plantation
colony, with an English governing^ class, on English methods,
and the other gradually converted into a purely European
colony where Dutch ideals would have full scope for evolution.
The idea may seem fantastic, and certainly cannot be described
as belonging to practical politics: I throw it out as a sugges-
tion for what it is worth.

Remembering, however, the immediate problem of how
the white and black races in contact are to attain satisfactory
economic relations with one another, I would venture to close
with an aphorism — that a country will, in tlie end, belong to
the people who do its work.

THE NITRUGEX PROBLEM

r»y J. A. WiLKixsox. M.A..

Professor of Cheinistrij , Uniccrsitij CoUefjc. JoJuni neshin (/.

Pnhlic Lecture, deJirered <>ii the ereuiitu of J u] ij lil. 1920.

The birth of tliis Association, under whose tegis we meet
to-night, took place in the year in which peace was restored To
this land after three years of strenuous war. I'lie development
of the country up to this period had proceeded slowly, but the
exploitation of the rich gold and diamond deposits gave the
spur to a lively interest from without and quickened activity
within for the sake of the wealth thus revealed. The heritage
of the conflict in which South Africa was engaged in the open-
ing years of this century may be stated in broad terms as the
gradual acknowledgment by the community that the time had
arrived for its evolution as a State and the utilisation of its
resources for the benefit of its peoples. The partial consumma-
tion of this idea took place in 1910, when the four southern
Provinces were welded into T^nion Its scientific evolution,
which this xlssociation was founded to assist, und has indeed
fostered to a remarkable degree, has hitherto seen its greatest
triumphs, on the one hand, in the establishment and rapid
development of facilities for the higher education of its citizens,
such as obtain in the older countries of the world, and. on the
other, in the foundation by the Government of scientific and
technical departments devoted to specialised branches of

* Illustrated by lantern slides specially prepared by the author.

96 THE XITEOGEX PROBLEM.

et-oiioiuic study. The early stages of this evolution have been
marked by a steady progress, as the pages of onr Journal can
prove, but at the commencement of any new work much labour
of a routine character is unavoidable. before Ave can place our-
selves in the front line with the scientific workers in older
countries, happy in the heritage of its accomplishment by those
who blazed the trail before them. During this period, whilst
we have been setting our house in order, great achievements
have been made in science in all its branches, and I shall
venture to-night to direct your attention for a brief moment
to one of the greatest of these, whether viewed from the
academic, commercial or national standpoint, namely, the
chemical problem of the fixation of atmospheric nitrogen, the
v-uccessful solution of whi(di has already proved of the most
profound significance, botli during the r)iping times of peace
and in the tempestuous struggles of the late war.

The Nitrogen Problem.
It has long been known to the farming community that
in the rotation of crops it was distinctly beneficial to include
a leguminous species, but the reason for this procedure was
not forthcoming until the researches of AVarington, and later
of Winogradsky, had explained the function of the enlarged
nodules found on the roots of these plants, namely, the bacterial
transmission of aerial nitrogen in compound form to the soil.
Again, the physiological chemist divides the foodstuffs which
maintain our existence into five well-known classes, one only
of these containing the element nitrogen, namely, the proteins.
Further, it has been i)roved by numerous experiments that, in
the absence of this particular class m a diet, life soon ceases,
thus establishing the fact that the element nitrogen is a neces-
sity for the maintenance of life. About the middle of last
century, Liebig, Lawes, Gilbert and others proved that for the
fullness of groAvth plants must be grown on a soil containing a
sufficiency of the elements nitrogen, potassium and i^hosphorus
in such form as to be easily assimilated by the roots. In virgin
soils, such as are to be found in all new countries, these com-
pounds exist in greater or less measure, but with cultiA'ation the
soil soon becomes exhausted and consequently unfertile. To
lemedy this defect with respect to the element nitrog^en, the
supijlies of saltpetre found in Chili were utilised, and this
substance proved to be excellent for the purpose. In addition
to this, the residual nitrogen found in coal, which is obtained
in the form of ammonia when this substance is destructively
distilled, has been utilised for this purpose since the early
'nineties to an increasing extent.

These two substances, sodium nitrate and ammonium
sul])hate, were the only artificial nitrogenous manures available
at the beginning of this century. In 1898 the late Sir William
Crookes drew the attention of chemists to tlie fact that the
available supplies of these two fertilisers were insufficient to
meet the demands whi(di would be created by the food require-
ments of the expanding population of the world ; at the same
time he drew attention to the oceans of free nitrogen present

TTIK NITROGEN PROBLEM. 97

ill tlie •atmosphere, wliicli plants, except tlie one family men-
tioned, were incapable of using-. In tins connection it is worth
noting' that twenty million tons of free nitrog-en have been
estimated to exist over every square mile of the earth's surface,
an amount sufficient, according" to the late Sir William
Ramsay, to afford plant food for over 38,000 years at the
present rate of consumption. The quantities of available
nitrogen from the Chili deposits and coal carbonisation were
such that they would in a relatively short period of time prove
insufficient to meet the demand created. ( )n the other hand,
the use of nitric acid and nitrates, particularly in the manufac-
ture of explosives, was also increasing-, thus decreasing- the
supply- available for plant nutrition, and other sources of these
compounds were, comparatively speaking', neg'lig-ible.

The problem wliidi therefore presented itself was the
conversion of this atmospheric nitrog-en into a form capable of
transference to the soil for utilisation by growiiig- plants, more
especially wheat. This is now known as the nitrogen problem,
and its solution forms one of the g-reatest achievements of this
century. The methods by which this has been accomplished
are as follows : — ^

1. Direct union with oxygen, forming nitric peroxide, and
solution of this in water, yielding- nitric acid and its salts. This
is effected by the agency of the electric^ arc, the processes in
commercial use being (a) the Birkeland-Eyde ; (b) the
Schoiiherr; (c) the Pauling.

2. Direct union -uith hydrogen, forming ammonia, and
solution of this in aqueous solutions of acids, yielding
ammonium salts, or oxidation to nitric acid, and formation of
ammoniam nitrate. This is effected by catalytic action at high
temperatures and pressures on the pure mixed gases. The
commercial process is known by the name of Professor Haber,
Avho successfully investigated the equilibrium of the reaction.

-.1. Eeaction with metallic carbides, forming cj'anamide
and carbon, the commercial process being known by the name
of the first product mentioned.

4. Union with metals, forming nitrides, which are then
decomposed, yielding- ammonia and its salts. These processes
are still in tiie experimental stage, the most promising being
tliat of 0. Serpek, which consists in heating bauxite with
carbon to about 1,800° C. and subsequent decomposition of the
aluminium nitride thus produced by steam or an. aqueous
solution of sodium hydroxide, yielding ammonia and alumina,
which is stated to be of sufficient purity for the preparation of
the metal by electrolysis.

5. Conversion into sodium (-yanide by heating a mixture
of soda ash and carbon with finely divided iron as catalyst to
about 950° C. and passing nitrogen or air through the mass.
The cyanide is lixiviated out with water and dried. It is then
melted and air passed through, thus yielding- cyanate, which
is heated with water to obtain the bicarbonate and ammonia.
This process is due to Professor J. F. Buchei and has n^t-j^-et,
been worked on the large scale. /''a^^^'4/

LIBRARY' ^

3^1

98 THE XITEOGEX TEOBLEM.

6. Conversion into the oxides of nitrogen by tlie explosion
of a combustible gas with air, and absorption of these gases by
water as in the first process. This is known as the Hiiusser. or
explosion, process, and has been worked on a small scale with
some success, using coke oven gas with air and exploding the
mixture in stationary bombs. If employed as a method of
producing power as well as nitric acid, the cost of the latter
would compare more than favourably with the products
obtained by the synthetic processes mentioned before, and the
scheme is therefore one which invites further experiment, in
spite of the great cost of the absorption plant which would be
required for the very low concentration of nitric oxides
obtained.

In addition to these, a large number of other processes
have been proposed, but serious attempts have not l)een made
to work them out commercially, and they are therefore for the
moment, so to speak, of academic interest only. The case is
otherwise with those specificallj' mentioned above, since the
first three processes are, commercially speaking, large pro-
ducers; and with regard to the last three, small plants are in
operation with a view to overcoming the difficulties incident to
large-scale production at a later stage. A brief account of the
methods used in the above processes, the character aiid amounts
of the products obtained and the factors needful for their
successful operation may not be considered out of place here.

1 a.— The Birlehind-Ej/de Process (1903).

This has the merit of being the first nitrogen fixation
process to meet with commercial success, having been intro-
duced in 1903, when large works were first erected at IVotoddeu,
in Norway, power being transmitted at 10.000 volts from the
Svaelgfos Power Station, three miles away, on the Tyn River,
where there is an effective height of fall of about 140 feet. Air
is driven at the rate of approximately 2 cubic metres (TO cubic
feet) per minute through a flame disc at a temperature of
2.000° C. to 3.000° C. produced by electro-magnetic deviations
of an electric arc. The electrode^ are made of thick copper
tubing and are water cooled. The diameter of the flame disc
is between two and three yards. By this meaJis a product is
obtained containing about Ih per cent, of nitric oxide. The
gases leave the furnace at a temperature of 800° to 1,000° C.
and are passed into boilers where the temjierature is reduced to
150° to 200° C, the heat being utilised to raise steam, to con-
centrate the final products, and for other purposes. They next
pass to the coolers, which consist of aluminium tubes cooled
externally by cold flowing water, and tlience to the oxidation
tanks, vrhich consist of vertical iron cylinders lined with acid-
proof stone. Here the nitric oxide combines with the
unconverted oxygen to form the peroxide. The cooled gases
are then forced through a series of granite absorption towers,
in which the peroxide is dissolved out by means of water, which
is used in the last tower but one of the series, the weak nitric
acid produced being then pumped to the top of the next tower
nearer the oxidation tanks, and so on. the gas and the solvent

THE NITEOGEX PROBLEM. 99

thus passing" in opposite directions. The gases, before being"
finally restored to the atmosphere, are made to pass up a tower
down which a weak solution of soda is passed.

■ The final products obtained in the absorption system are
nitric acid of a concentration about 35 per cent., and in the last
to'v\er sodium or calcium nitrite and nitrate. Formerly, the
nitric acid obtained was neutralised by flowing on to limestone
contained in granite vats, a watery solution of calcium nitrate
being thus obtained, which was afterwards concentrated in
vacuum evaporators to a certain strength and then poured over
steam cylinders for final solidification. The salt thus produced
was found to be deliquescent and the basic nitrate was then
manufactured, but this also was abandoned in favour of the
manufacture of concentrated nitric acid. By these means
about 95 per cent, of the oxidised nitrogen passed through the
system is recovered in practice. The fundamental reactions
which take place are : —

(a) In the flame disc, N", + 0o^=52 NO.

(b) After cooling- the exit gases,

2 K'O + Oo 600^- 2 XOa li^- NX)^.

(d) Subsequent oxidation, 2 HNO, + 0, = 2 HXO3.

As shown in the equations, these reactions are reversible,
and the dynamics of the process has been studied theoretically
with useful results, by passing air into a platinum globe
heated to a high temperature in an electric furnace, and after
equilibrium had been attained cooling quickly by passing the
gases through a capillary tube and then analysing. The
concentration of nitric oxide at various temperatures was thus
obtained, both by experiment and calculation, as also its rate
of formation and decomposition, which afforded valuable data
for the conduct of operations on the large scale. By increasing
the volume of oxj^gen in the mixture until it was equal to that
of the nitrogen, the concentration of the nitric oxide was
increased, as also by decreasing^ the rate of flow through tlie'
heated globe, but in practice these have not been adopted
generally.

Ih.—The l^chonhrr Process (1907).

This differs from the above only in the type of furnace
used, which consists of a vertical cylinder 23 feet high lined
with refractory brick, inside which is an iron tube about
five to six inches in diameter containing an insulated electrode
at one ^vA, the tube itself serving as the second electrode.
Air is introduced into this tube with a tangential or rotary
motion, and the arc which is formed between the insulated
electrode and the adjacent tube is thus drawn out to a length
of six to seven yards. The gases leave at the upper end at a
temperature of about 2,000° C, and are cooled by a water
jacket placed round the arc tube near the top, and, secondly,
by being made to heat the incoming air. The furnace requires
about 40,000 to 50,000 cubic feet of air per hour, and is

100 THE NITROGEN PROBLEM.

generally constructed for 600 to 1,000 kilowatts. Compared
with the Birkeland-Eyde furnace, it is much smaller, and a
larger installation is therefore required to give the same
output. On the other hand, the apparatus is simjjle, durable
and comparatively inexpensive. Tlie further treatment of the
nitrogen oxides and the final products obtained are the same
as in the former process.

1 c. — The Pauling Process.

In this arcs are employed, which are produced between
two electrodes curved like those of the so-called horn lightning
arresters, the air being blown through and along them from
the parts of the electrodes which are nearest together, the
minimum distance being large enough to allow of the air
passing through. TJie preheated air current is blown over the
arc in such a manner that it passes along the whole length of
the electrodes, which are made of iron and are water cooled.
Cooling of the exit gases is effected by passing cold air into
the upper part of the flame from the side at a slower rate
than the main air current, wliich has the effect of broadening
the flame. Two arcs are contained in one furnace, and for a
400-kilowatt furnace 600 cubic metres of air are used per
hour. The gases leave the furnace at a temperature of 800° C.
In 1909 it was stated that 60 grams of nitric acid were
produced per kilowatt hour by this process, which was first
established on the large scale at Patsch, near Innsbruck, in
Tyrol, and afterwards at La Eoche de Eame, Hautes Alpes,
France. The furnaces are ^im])le in construction, about
3ft. by 4ft. in horizontal section and 10ft. liigh, and about
600 to 1,000 kilowatt capacity. The air is preheated before
entering the furnace by utilising the heat of the gases leaving
the furnace, and this is also utilised to concentrate the acid,
which is marketed as such or may be neutralised to form salts.

/ (1 . — The Moscicici Process.

This has been worked hitherto on a semi-commercial scale
and differs from those previously mentioned in the method of
obtaining the flame. Two concentric ring electrodes are used,
the arc passing from one ring to another in a radial direction
and being magnetically deviated as in the Birkeland-Eyde
process, which causes it to revolve continuously arf)uncl in the
annular space between the rings, hence tlie designation which
has been given to this, namely, tlie revolving flame metliod.
It is stated to liave given a yield of 60 grams nitric acid per
kilo'\\att hour and to be well adapted for direct current o^^jera-
tion, It has, however, now been discontinued.

In addition to tlie simple reactions already stated to occur
when air is passed through an arc flame, there are others
which militate against a complete theoretical extraction of the
oxides of nitrogen produced. The gas wliich leaves the oxida-
tion tanks for the absorption system consists of 98' 5 to 99 per
cent, of air and 1 to T5 per cent, of the mixed oxides of
nitrogen from XO to XoOf which when dissolved in water
yield nitrous and nitric acids. In the absorption towers other

THK NITROGKX PROBLEM. 101

reactions take place — e.g., the decomposition of the iiitrons
acid yieldini^" nitric oxide,

3 HNO, > HNO3 + 2 XO + H3O.

The NO thus produced must be reoxidised by nitric peroxide
or oxygen or lost. If reoxidised it is possible that a mixture
of nitric oxide and peroxide acting- as jSTjOg may be produced,
which is caught by the alkali wash of the last tower yielding
sodium nitrite — in fact, the salt obtained from this tower is a
mixture of the nitrite and nitrate, in which the former
predominates.

These arc processes depend commercially on a cheap and
abundant supply of electric energy, since only 3 to 4 per cent,
of the electric energy is used in effecting' the union of the
nitrogen M-ith the oxygen ; also, owing to the low concentra-
tion of XO, the oxidation and absorption systems must be
large and therefore costly. The total cost of electrical energy
per kilowatt year at Svaelgfos and Notodden is the smallest in
the world, being about tliirteen to fourteen shillings, as com-
pared with i)Ounds in this country.

II.— The Haher Process (1910-13).

The reaction of nitrogen with hydrogen to form ammonia
gas has been known for a long time, as also the fact that the
amount of ammonia thus formed is very small. Xernst and
Jost in 1907 examined this reaction, using a pressure of
50 atmospheres, and at a temperature of 700° C, with
manganese as a catalyst, obtained a concentration of less than
1 per cent. Haber and le Rossiguol a little later studied the
reaction at higher pressures, and with osmium as catalyst
obtained an 8 per cent, concentration. The l^adische Anilin
and Soda Fabrik then took up the process, and made it a com-
mercial success, at the same time undertaking researches to
discover cheaper catalytic reagents. The nitrogen is obtained
by the fractional distillation of liquid air, and the hydrogen
by that of liquid water gas, freed from carbon dioxide before
liquefaction. Very little has been published regarding this
process other than the scientific researches of Haber and
le Rossignol, which showed that the most favourable working-
conditions were a pressure of between 100 to 200 atmospheres
and a temperature of about 500° C. This gives on the large
scale a 5 to 6 per cent, concentration for one passage of the
g'ases. From a chemical engineeiring point of view, such
conditions were abnormally severe, more especially when
dealing' with a gas such as hydrogen. Tliat they have, how-
ever, been successfully overcome is now a matter of common
knowledge.

On leaving' tJie furnace where the conversion takes place,
the mixed nitrogen, hydrogen a ad ammonia are passed into a
refrigerating oi- al>sorption system, wliere the ammonia is
liquefied or absorbed, the residual gases being returned to
the system. The catalyst in commercial use is believed to be
a specially prepared form of iron containing a minute quantity
of potash. It is very easilj^ poisoned, and must therefore be

102 THE NITROGEN PEOBLEM.

carefully prepared and protected, which necessitates the
purification, in the first instance, of the gases used. The first
cost and maintenance of the plant used is large, and the
preparation and purification of the gases, especially hydrogen,
are also costly items, but, in spite of these, ammonia can be
produced at a cheaper rate by this process than in any other
way. The ammonia obtained may be marketed as such or
treated with acids to form salts or oxidised by means of air
to form nitric acid and then ammonium nitrate.
III. — The C yananude Process.

In 189-1: calcium carbide was produced on the large scale
by the process discovered independently by Moissan anfl
Wilson. In the following year Frank and Caro, in attempting
to prepare potassium cyanide for gold extraction by the
Macarthur-Forrest process, passed nitrogen over barium
carbide mixed with soda heated to 700° C. to 800° C, and
found that about 30 per cent, of barium cyanide was formed
and, in addition, 45 per cent, of barium cyanamide. When
the price of cyanide fell owing to the Boer War, they used the
cheaper calcium compound, and observed that cyanamide alone
was formed. This substance, when treated with water, yielded
ammonia, and after some nreliminary trials quickly found
extensive use as a fertiliser under the name nitrolime or
lime nitrogen. At first, however, ammonium sulphate Avas
prepared from it by placing it on trays in a tower up whicli
steam was passed, tbe ammonia set free being subsequently
dissolved in sulphuric acid. At high pressures this reaction
with steam is almost quantitative, and is stated to give a
95 per cent, efficiency on the large scale.

The raw materials used in this process are lime, coke and
nitrogen — substances which can be obtained in abundance and
plenty. This, coupled with the fact that the raw product can
be used directly as a fertiliser, and also that the power require-
ments are small, has made this the most popular form of
nitrogen fixation, large factories being established in France,
United States of America, Canada, Italy, Scandinavia and
Japan, as well as in Germany. The nitrogen is now almost
universalh' obtained by distilling liquid air according to the
inventions of Claude and Linde, based on the dift'erences of
the boiling points of nitrogen -196° C, air -194° C, and
oxygen -188° C. The nitrogen so obtained is guaranteed not
to contain more than ()-4 per cent, oxygen, and this small
amount has caused no difficulty in practical working. It may
be mentioned also that this method of obtaining on the large
scale the gases of the atmosphere in liquid form and separating
their constituents by fractionation is also one of the notable
achievements of this century, based primarily on the
researches of Professor Andrews on carbon dioxide in 1869,
which first provided tjie key for the solution of the problem.
He proved that all gases must be reduced in temperature lielow
a certain point, known as the critical temperature, and when
this Avas done pressure alone would serve to bring about the
change to the liquid state. As a result of this discovery all
known gases were reduced to lic|uids on a laboratory scale,

THK XITEOGEX PROBLEM. 10-'^

the last being- helium, which was liquefied in 1908 by
Professor Kamerliugh Dimes at the University of Ley den.
Linde and Claude worked out tlie problem of their large scale
manufacture, and so provided a most convenient and suitable
method for procuring- the necessary nitrog-en from the
atmosphere. What this means will be realised from the fact
that at Niagara 2,000,000 cubic feet of nitrogen are required
and obtained per day. Lime is prepared by the usual method
of burning limestone in kilns, mechanical arrangements of the
most modern type being* installed for charging', discharging-
and grinding to ensure economical working.

Coke is manufactured from coal, the gaseous distillate
being also utilised in the lime kilns, or, if the old copper
method of obtaining nitrogen from the air be in use, in the
reduction of the oxide formed. The lime and coke are then
burnt in large electric furnaces of 10 to 20 tons capacity,
working with a low voltage and high amperage to form a higii-
grade calcium carbide, which is tapped from the furnaces at
regular intervals into trays and allowed to cool in a current
of air. The material, containing- about 80 per cent, pure
carbide, is then ground to a fine powder in a gas-tight
apparatus filled with nitrogen, an operation otherwise not
unattended with danger owing to the explosive power of
carbide dust, and is then placed in the cyanamide ovens of one
to two tons capacity, heated electrically, and nitrogen passed
in. Great care has to be exercised in this operation, since the
reaction is reversible and strongly exothermic, which necessi-
tates but little electric energy to keep t]ie temperature up to
800° C. to 1,000° C. required^ After 80 to 40 hours the hard
cake of cyanamide is removed, cooled, and then ground to a
fine powder in an atmosphere of nitrogen in rock-breaking
machines.

To prepare it as a fertiliser, it is partly slaked to ensure
decomposition of any carbide which has been left undecom-
posed, then stored in silos until ready for packing and trans-
portation. In addition to its use as a direct plant food,
cyanamide is also used for case hardening- iron goods, as a
source of ammonia, and, when heated with a flux such as soda
or common salt, for the preparation of crude cyanide. In the
production of ammonia the reaction is carried out in steel
autoclaves of 1,000 cubic feet capacity almost filled with water
or alkali solution, the cyanamide being run in as a fine powder
with vigorous stirring, after which superheated steam is
admitted up to four atmospheres pressure. Since the reaction
itself is exothermic, the evolution of ammonia soon commences,
and the steam ammonia mixture given off is rectified, yielding
an aqueous solution of ammonia of great purity.

Although the reaction between calcium carbide and
nitrogen appears simple when written down as an ordinary
chemical equation, CaCo + Nj ^N.Ca.ClST. + C, several investi-
gators, including Professor Haber, have attempted to
determine the conditions of equilibrium at varying- tempera-
tures and pressures without success. Pure carbide does not
react, according to Moissan, with nitrogen, whereas the

104 TIIK XITROGEX rKOliUQU.

teclinical operation proceeds smoothly, the impurities therefore
acting- catalytically. Calcium chloride has proved to be a
most efficient catalyst, the reaction velocity being markedly
increased and the temperature lowered to TOU° C

As has alreadj' been stated, the substances prepared and
commercially marketed by the above three synthetic processes
were, in the first instance, intended to supplement the yield
of nitrogenous fertilisers, the sodium nitrate obtained from the
Chili fields and the ammonium sulphate, which was won as a
by-product when coal was carbonised in gas, shale, iron and
coke oven works and in the manufacture of producer gas. The
outbreak of the European War in 1914, however, necessitated
the use of an enormous quantity of explosives, in which
nitrogen jjroducts became of overwhelming importance,
chiefly in the form of nitric acid, for the preparation of nitro-
cellulose and nitro-aromatic derivatives, such as tri-nitro-
toluene, lyddite, tetra-nitro-aniline, nitro-naphtlialene, etc.,
and, in the later stages of the war, ammonium nitrate, which
was the chief ingredient of the am^ional used by the Allies
and donarit used by the enemy.

In its first stages the Allies, owing to command of the
sea, were able to satisfy their requirements by direct importa-
tion from Chili, but this was denied to the Germans, who were
therefore compelled to rely solely upon synthetic nitrogen.
The commercial realisation of the Haber process took place in
1913, and it is noteworthj^ in this connection that German
capital which had been invested in the Schonherr process was
withdrawn at this period, probably owing to their faith in the
new process, a faith which, as the sequel will show, was not
misplaced. The production of ammonia alone, however, would
have been of little assistance from the military point of view,
since the nitrogen was required in the form of concentrated
nitric acid. This substance could be, and was, obtained in
small quantity from the Norwegian arc process factories, but
concurrently with the investigations of Professor Haber into
the ammonia reaction, Professor Ostwald undertook a study of
the oxidation of ammonia by means of air in the presence of
catalysts. That this proved successful is now only too well
known, since the commercial realisation of the Haber-Ostwald
ammonia oxidation processes enabled Germany to prolong the
war to an extent which would otherwise have been, practically
speaking, impossible, since this material is easily by far the
most important munition of modern warfare.

It will be seen, therefore, that these processes have a
significance and value as great in times of war as in those of
peace, and owing to this fact have already attained an import-
ance of a trulv national character, in that the Governments of
the Fnited Kingdom and the ITnited States appointed strong
Commissions to investigate the problem and formulate such
measures as were necessary to safeguard the nation, both n\
peace and war, and render it self-supporting in this regard
in the same manner in which Germany had accomplished this
before war was declared. The increased output of these
processes under the stress of war is shown in the following

THE NITROGEN PROBLEM. 105

table, wliicli was prepared by the English Commission, known
as the N"itrogen Products Committee : — ■

PRODUCTION IX METRIC TONS.

Norwegian Arc. Processes

l'.tl8. 1914. l'.)\r>. 19U;. 1917.

Ca and Ammonium Nitrates 80.031 87,135 ().5,068 105.610 99,490

Haber Process (in terms of

Ammonium Sulphate) ... (30,00o) (G0,00u) (150,000) (300,00o) (500,000)

Cjanamide (156,944) (194,726) (771,155) (981,500) — .'—

The figures given in brackets indicate the estimated
productive capacity. The Haber process has not yet been
installed outside Germany. In addition to this, Germany
possesses large by-product ammonia and cyanamide plants.
The intensive utilisation of these factories enabled that country
to provide both the fertiliser for the wheat crops as well as
the nitric acid for the unorecedented amounts of explosives
which were used in the four and a half years of uninterrupted
warfare.

The rapid development of these synthetic processes when
compared with existing nitrogen industries is shown in the
following table given by the Committee in terms of fixed
nitrogen : —

1914.

1918,

M. Tons.

Chili Nitrate

... 418,000

465.000

41-4

Bj-Product Ammonia

288,000

36-6

340,000

30 3

89-6 71-

Arc Processes

10,000

1-3

27,000

2-4

Haber Process

12,000

1-5

100,000

8-6

Cyanamide Process

60,000

7 6
10-4

190,000

170
28-3

The costs of production (Table A) have also been worked
out under English conditions, and are interesting as showing
that the Haber process compares favourably in this respect
with all other existing processes ; at the same time, owing to
the purity of the ammonia produced, it is particularly adapted
to the preparation of nitric acid or amnnmium nitrate.

The research and experimental work done by the British
Government during the war was undertaken with a view to
the commercial establishment of a synthetic process in
England, but this had not been accomplished when the
Armistice was signed in 1918. The work, however, is not to
be lost to the country, as a company, called " Synthetic
Ammonia and Nitrates, Limited," has just been formed to
take over from the Government the plant for the manufacture
of nitrogen products from air and to develop this manufacture
on the commercial scale. The method to be employed is a
modification of the Haber process, as improved by the results

106

THE >-ITROGEX PROBLEM.

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THE NITROGEN PHOBLKM. 107

of the researches indicated above, and it is stated that the
eoinpauy intend to erect immediately a phmt for the manu-
facture of 100 tons of 100 per cent, ammonia per day, with
provision for a rapid extension to 300 tons a day, equal to
150,000, rising- to 450,000, tons of sulphate per annum. With
the successful establishment of such a plant, England will in
future be free from the menace of being- dependent on other
countries for her nitrogen needs and requirements.

In examining- the case for this country, it is necessary, in
the first place, to study the importation of nitrogen compounds,
which are shown in Table B for the last decade-
Inspection of this table shows at a glance the enormous
amount of sodium nitrate imported for the manufacture of
nitro explosives for mining- purposes, and of cyanides for the
extraction of gold. If we include also the imports of manu-
factured explosives, it will be seen that, compared with these
items, the rest are relatively insignificant, and the conclusion
mig'lit therefore be drawn that, outside the mining industry,
the nitrogen problem was a matter of no importance to this
country. Such an inference wouldj however, be unjustifiable
from the point of view of the expanding agricultural industries
of South Africa, which in a short time will demand large
supplies of nitrogenous fertilisers. The C{uestion therefore
naturally arises whetlier it will be possible to meet such a
demand and at the same time assist the explosives industries
by manufacturing" nitric acid within the country itself.

The only two possible sources of any consequence at
present known are the coal deposits (including shales) and the
nitrogen of the atmosphere. With regard to the former, as
I have shown elsewhere,* according to the most reliable
estimates obtainable, namely, those of the Union Goveimment
Mining Engineer, the resources of South Africa are small in
extent, forming only four-fifths of 1 per cent, of the world's
coal reserves, as against 2h per cent, in Great Britain, and at
the same time it must be remembered that the quality of
much of this coal is as yet unknown. At present the greater
bulk of the coal mined is burnt completely to ash for the
purpose of raising- steam and the nitrogen is not recovered.
There is one plant at Mount Xgwibi, near Vryheid, in T^atal,
in which coal is burnt to destruction in Mond producers to
obtain its nitrogen, in the form of ammonium sulphate, the
by-products not being utilised. These works have been in
existence three years, and up to the end of last year produced
about 8,500 short tons, so tha^- tlie total production at the same
rate up to the present would be approximately 10,000 short
tons, or 9,080 metric tons. In addition, there are four coal gas
works, but the amount of nitrogen products recovered is,
practically speaking, too small to be taken into account. iVt
the present moment, therefore. South Africa is compelled to
import nitrogen for manufacturing- purposes, that required for
agriculture being, as far as can be judged, small in amount.
In war, the country would in this respect be entirely dependent

*Cf. BuUcfln 28, Union Dept. of Industries.

108

THE >-ITROGEN PROBLEM.

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THE XITEOGEX I'KOBI.KM.

109

ou imported uitrate or nitric acid, as at present, except for the
works mentioned above^ where the ammonia recovered would
require an additional and costly plant to oxidise it to nitric
acid.

The other and h\ tar greater source of nitrogen com-
pounds is as yet untouched, but the success which has attended
the installation of synthetic nitrogen processes dependent on
cheap electric power naturally turns our thoughts to the only
source of water power in this country of any magnitude — the
beautiful Victoria Falls. The most reliable data concerning
this which I have been able to obtain are those given by the
recent survey undertaken by the Ehodesian Munitions
Committee, which, I believe, confirms the estimate of
500.000 available B.H.P. formerly made. That such an amount
of energy must remain indefinitely unutilised for the benefit
of the country is difficult of belief, but, on the other hand, it
should not be forgotten that, in comparison with the water
power available in other countries, it is not by any means
considerable in magnitude, as the following Table C compiled
by the Minister of the Interior of the Canadian Government
shows : —

Table C.

B.H.P. DEVELOPED

BH.P.
AVAILABLE.

COUNTRY.

B.H.P.

PER CENT.

N.S. America

28.100,000

7,000,000

249

Canada A. ...

18,80:-5,000

1,735.000

9-2

Canada B. ...

8,094,000

1.725.000

21-3

Austria-Hung-ary ...

6,460,000

566,000

8-8

France

5,587,000

1,100,000

11 -6

Norway

5,500,000

1,120,000

20-4

Spain

5,0()0,00t)

440.000

8-8

Sweden

4.500,000

704,000

15-6

Italy

4.000,000

976.000

24-4

Switzerland

2,000,000

511,000

25-5

Germany ...

1,425,000

618,100

43-4

Great Britain

1168.000

80.000

8-3

Though this is not the only chemical industry contingent
on water-power engineering, yet I cannot conceive of one more
fundamentally important to the country or one which would
confer greater benefits on the community. The sources of
energy with which South Africa is endowed from a commercial
point of view at the present moment are the coal reserves
and the water power of the Victoria Falls. Both these are,
when compared with the resources of other countries, small
in magnitude, and hence, in the interests of the country,
demand, from the standpoint of national economy, rational
and scientific utilisation, or, in otlier words, conservation in
the liighest degree. The only other source of energy witli
which the country is happily endowed in large measure is the

110 THK XI'J'ROGEX PROBLEM.

suji, wliicli finds its field of iiftioii also to so large an extent
in the vegetable kingdom.

Plants haA'e harnessed the sun, and are thus enabled to
bring about chemical processes and reactions of the most
unending variety and the most beautiful kind, compared with
which the methods of the laboratory are crude and unrefined.
By nourishing the plant within the soil from the boundless
stores of nitrogen in the air, we shall at least in one respect
effect tlie development of the land awaiting cultivation in this
country and give a spur to the utilisation of its real values.
Whether it will be possible to increase the potential of the
sun's energy, and thus obtain power of the intensity which is
usually associated with this word is for future iuA-estigation
and research. As is well known, serious attempts to solve
this problem have already been made. When it is achieved
South Africa will be rich indeed.

LIST OF PAPEES READ AT THE SECTIOIs^AL
MEETINGS.

Section A. — Astronomy, Mathematics, Physics, Meteo-
rology, Geodesy, vSurveying, Engineering, Architec-
ture AND Irrigation.

WEDNESDAY, JULY 14, 1920.

1. Presidential Address on " Recent Progress in Astronomy " bv

H. E. Wood, M.Sc.

TRUBSDAY, JULY 15.

2. The effect of high temperature and altitude of Aerodrome in the

taking off of Aeroplanes: P. G. Gundky, B.Sc, Ph.D.

3. A short note on Einstein's planetary equation : W. N. Roseveare,

M.A.

4. Rainfall and barometric variation in Bulawavo : E. Goetz, S.J.,

MA.

5. 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 time of rising and
setting. J. T. Mokkisox, M.A., B.Sc.

Section B. — ^Chemistry, Geology, Metallurgy, Miner.vlogy
AND Geography.

THUBSDAY, JULY 15.

1. Presidential Address on " Geology in relation to Mining " l)y

F. P. Mennell, F.G.S., M.I.M.M.

2. Bat Guano deposits of Rhodesia : E. V. Flack.

3. Some further factors influencing the solubility of Phosphoric Oxide

in mixed fertilisers containing superphosphates : E. V. Flack.

4. The geological section between Bulawavo and the Victoria Falls:

H. B. Maufe, B.A.

5. Karroo rocks in the Mafungabusi, Southern Rhodesia: A. J. C.

Molyneux, F.G.S.

6. On the volumetric determination of Phosphoric Oxide: B. de C.

MAIiCHAXD, B.A., D.Sc.

LIST OF rAl'EKS READ. Ill

SATUIWAY, JUI.Y 17.

7. Magnesia impregnated soils: G. N. Blackshaw, O.B.E., B.Sc.

8. Note on Kimberlite from the Belgian Congo: P. A. AVacixer. Ing.D.,

B.Sc.

9. Calibration of Gerber milk bntvrometers : C. 0. "Williams, B.Sc.

Sectiox C. — Botany, Bactekiologv, Agrictltuee and
Forestry.

FBIDAY, JULY 16.

1. Presidential Address on " Causes leading toward progressive evolu-

tion of the Flora of South Africa " by T. R. Sim, D.Sc.

THURSDAY, JULY 15.

2. Ericoid leaves: D. Thoday, M.A.

.1 Hakea leaf: Hoi?ACE A. Wager, A.R.C.S.

4. South African Fern notes: T. R. Sim, D.Sc, F.L.S.

o. The constituents of the Flora of Southern Rhodesia: F. Eyles.

6. Ilcemanthus coccinius: A. Mennie.

7. The occurrence of " Terblanz " {Faiirca macnaufjhfouii, Phill.) in

Natal and Pondoland : E. P. Phillips, M.A.. D.Sc.

8. A paw-paw leaf spot caused bv a Pli ijllosticta sp. : P. A. van der

BijL, M.A., D.Sc.

9. Note on the i-Kowe or Natal Kafir mushroom — Schulzeria um-

Kowaan, Cke. and Mass.: P. A. vax eer Bi.jl, M.A., D.Sc.

10. Additional host plants of Loranthaceae occurring around Durban,

with concluding summary: P. A. van der Bijl, M.A., D.Sc.

SATUBBAY, JUJ.Y 17.

11. Note on the Crassulaceee found in Rhodesia : S. Schonlaxij, M.A.,

Ph.D.

12. Ripening of the seed in Gnetinn gncmon and Gnetum Africanum:

Mary G. Thoday.

13. The distribution of accessory food factors (Vitamines) in plants:

E. Marion Delf, D.Sc.

14. A preliminarv note on the flora of the neighbourhood of Bethlehem.

O.F.S. : E. P. Phillips, M.A., D.Sc.

15. A method of Veld estimation: A. 0. D. Mogg, B.A.

16. A contribution to the Polyporefe of the Union of South Africa :

P. A. VAN der Bi.jl, M.A., D.Sc.

Section D. — Zoology', Physiology, Hygiene and Sanitary

Science.

WEDNESDAY, JULY 14.

1. Presidential Address on " Some Zoological factors in the economic

development of South Africa " by C. "W. Mally, M.Sc.

THURSDAY, JULY 15.

2. Some parasitic Protozoa found in South Africa. III. : H. B.

Faxtham, M.A., D.Sc.

3. The life-history of tlie Afi-ican sheep and cattle fluke, Fa-<rioIa

giganttca : 'Axxie Porter, D.Sc, F.L.S.

4. The economic importance of a study of Nematodes: J. Svndghouxd,

B.Sc.

5. The telluric and climatic conditions causing Gallamziekte : E. R.

Hartig, D.V.M.

6. Lamziekte and its treatment: Sir Arxolj) Thetler, K.C.M.G.. and

H. H. Greex, D.Sc.

IT- LIST OF PAPERS READ.

7. A Tachinid parasite of the honey-bee: S. H. Skaife, M.A., M.Sc.

8. Some factors in the natural control of the wattle bagworm : S. H.

Skaife, M.A., M.Sc.

9. A note on Dasychira extorta and its Lepidopterous parasite: C. P.

VAX DER MeKWE.

10. Birds and insects in Bushman folk-lore : Miss D. F. Bleek.

SATUTWAY, JULY 17.

11. Observations on live snakes in captivity: Henrietta FitzSi.mons.

12. Snake venom and its effects: F. W. FitzSi:mons.

13. Some Cercarite found at Durlian : F. G. Cawstox. M.D.

14. Preliminary note on the toxic effect of methylene blue injected into

domesticated animals: G. de Kock. M.R.C.V.S.

15. The classification of Trypanosomes : P. J. nu ToiT. Ph.D., D.V.M.

Sectiox E. — AxTHEOPOLOGY, Etiixology, Xative Education,

Philology and Xative Sociology.

THUBSVAY, JULY 15.

1. Presidential Address on " The magic conception of Nature among

Bantus " by Rev. H. A. JuxoP.

2. The future of the native races of Southern Rhodesia : N. H. "Wilsox.
'■]. Note on older palseolithic implements from the Umguza and Bembesi

valleys: A. "W. Macgregok. B.A.

4. An exhiliit of stone implements from Tiger Kloof and Taungs. Cap&

Colony : Rev. Neville Joxes.

5. Note on rock-gravings at Metsang, Bechuan;ilnnd Protectorate:

A. J. C. Molyxeux, F.G.S.

6. Circumcision regiments as a native chronologv: Rev. "NV. A. Nortox,

M.A., B J.itt.

7. Plants of Bechuanaland : Rev. W. A. Nortox, M.A.. B.Litt.

8. Praises of chiefs: Rev. W. A. Nortox. M.A.. B.Litt.

9. Place names — map: Rev. W. A. Ndrtox. M.A.. B.Litt.

SATriiBAY. JULY 17.

10. Some features of the religion of the Ba-venda : Rev. H. A. Jcxod.

11. Cattle as a factor in Bantu economic development: Rev. J. R. L.

KixGox, M.A.

12. Notes on the Boskop skull: Rev. J. R. L. Kixoox. M.A.

13. Primitive speech, or the growth of a language: Rev. W. A.

Crabteee, M.A.

14. Hottentot place-names : Rev. C. Pettmax'.

15. Notes relating to aboriginal tribes of the Eastern Province: John

Hewitt, B.A.

16. On some stone implements from Strandlooper sites in the Eastern

Province: Rev. P. Stapletox, S.J.

17. Map of South Africa, showing the chief native languages and

dialects: Hev. G. Beyer.

Section F. — Educatiox. History, Mextal Sciexce. Political
Ecoxo:my, Ctexeral Sociology axd Statistics.

SATUBBAY, JULY 17.

1. Presidential Address on " Labour conditions in South Africa " by

R. A. Lehfeldt, B.A., D.Sc.

2. Agricultural economics (cost of production of maize) : Rt- A.

Lehfeldt, B.A.. D.Sc.

3. Crime and feeblemindedness: G. T. Morice, K.C, B.A.

4. Geographical method: J. Hutcheox", M.A.

THE GEOLOGICAL SECTIOX BETWEEX BFLAWAYO
AXD THE VICTORIA EALL8.

By H. B. Mauik, B.A.,

Director, GeoJogiccd Surreij, S. HJuule.-'ia.

]] itii ( >nc Fold III (/ Map
Read JuJn 15, 1920.

The geological section exhibited has been compiled from
observations made on many different occasions. It follows
closely the line of railway running north-west from Bnlawayo
to the Yictoria Falls, the chief exceptions being an extension
to the south-east of the Matopo Hills and a straight line drawn
across country from Inyantue to Wankie, where the railway
makes a wide detour to the south-west. Also, in places where
the railway makes a considerable curve to obtain grade on
ascending- the basalt scarp bej^ond Nyamandhlovu and on
descending it approaching Sawmills, the section has been
shortened to give the scarps their due gTadient. It has been
possible to draw the section to scale through tlie courtesy of
the engineers of the Rhodesian Railways in supplying levels;
and to the same source and to Mr. A. J. C. Molyneux I am
indebted for information from wells and boreholes, wliich has
served to increase materially the accuracy of the tliickness of
the beds. (See folding map.)

The section extends over a length of 282^ miles. The
liorizontal scale is 2i miles to the inch, and the vertical scale
500 feet to the inch, thus being* exaggerated over 26 times.

Three formations are encountered along the course of the
section, apart from alluvia and residual soils. The oldest
formation is the crystalline schists with granite intrusions and
dolerite dykes ; the second formation is tlie sedimentary beds
of the Karroo system, and the youngest is the Kalahari sand.

The oldest formation appears at the surface on two
portions of the section — first, on tlie high veld between
Bnlawayo and the Matopn Hills, and again between Dett and
Wankie. The first portion you will pass over on your journey
to the Matopo Hills. The crystalline schists consist of green-
stones and the banded ironstone or quartz-magnetite rock.
Both groups are strongly folded, and dip at liigh angles. Tlie
greenstones are metamorphosed basic ig'neous rocks, generally
hornblende-bearing rocks such as epidiorite and amphibolite.
Certain bands in them are vesicular or amygdaloidal, and other
portions show well-developed pillow structure. In parts of
the country, too, agglomerates and tuffs appear interbedded
with them. Tl'ere is little doubt that the greenstones repre-
sent in the main a succession of volcanic rocks. The horn-
blendic greenstones decompose to t]ie red clay soil wliicli you

114 GEOLOGICAL SECTION, BULAWAYO TO VICTORIA FALLS.

see iu and around Bnlawayo. As I do not know of any outcrop
of banded ironstone on the Matopo road, I will not say
anj^thing- further about it.

About half-way between Bulawayo and the Dam Hotel
you will pass over stretches of pale sandy loam. This is the
soil overlying- some metamorphosed acid igneous rocks, which
are generally spoken of as felsites. In many instances they
are intrusive into the greenstones and banded ironstones, and
appear to be closely related to the granites.

The granite of the Matopo and the g-ranite north-west of
Bulawayo are medium-grained biotite granites containing a
considerable percentage of oligoclase felspar, and have not as
a rule a strongly marked gneissic banding. The Hillside mass
is a small one, and exhibits many variations of composition,
some of which are without quartz, the mass being spoken of
as the Hillside syenite.

The crystalline rocks exposed between Dett and Wankie
include massive granite, as well as strongly-banded gneissic
varieties, some of which are graphitic. The pegmatites cutting-
these gneisses contain, in some places, large plates of mica;
in others, tourmaline and traces of tinstone. The relation of
these rocks to the greenstones and granites of tlie liigli veld
is not known.

The rocks of Karroo age show three types of development.
The oldest Karroo rocks containing GJossopieri.s are exi)Osed
around Wankie, and consist of a succession of grits, sand-
stones and black shales with coal. In the station yard at
Wankie you will see the top of the black shale group in which
the Main Coal-seam lies overlain bj" a thick bed of silicified
fire-clay.

Above these sandstones and shales is about 700 feet of
grey shales (Madumabisa Shales), with argillaceous limestone
bands overlain by -300 to 400 feet of reddish pebbly grits.
These Escarpment grits form the cappings of the higli tabular
hills which surround Wankie, and actually you will pass over
them in the train near Lukosi before reaching Wankie.

On the high veld the Karroo rocks are of Stormberg age,
as proved by reptilian remains. The succession consists of a
fine white sandstone about 200 feet thick overlain by four
basalt lava flows, between each of which there are in places
lenticular beds of red sandstone with oblique bedding-
(Nyamandhlovu Sandstone). These sandstones, with basalts
above and below", may be seen from the train on descending-
the scarp just before reaching Sawmills. An important point
which this section does not prove is the relation of tlie high
veld facies to the succession in the Wankie coalfield. The
two facies come together in the Gwaai Valley, east of Malindi.
I had hoped to liave visited the area and settled the point
before this meeting-, but have not been able to do so.

Between the Deka fault and tlie Victoria Falls you will
pass over a great tliickness of basaltic lavas, which are almost
certainly of the same age as the basalts of the high veld.
Xear Deka thin sandstones are interbedded with the l)asalt
as on the high veld, but thev have not yet been found at the

S.A. JOURNAL OP SCIENCE, VOL. XVII.]

GEOLOGICAL SECTION FROM THE MATOPO HILLS TO THE VJCTOPJA FALLS.

[PREPARED BY H. B. MAUFE.

Matdpos Umzincwani
River

Nyamandhlovu

VERTICAL SCALE EXACCERATID Z6 TIMES

Sawmills

Victoria

Falls 4000

q BASALTS & INTERBtDDED pr^

"iSANOSTONeS ^

mYAHANOHLOVUI

I- .• .- \£SCAIIPIIENT tZ->>-d MA DUMA BISA E
1.' ." -V lmT krZ-~--M MALE5 I

5:5] SANDSTONES &
t-d SHALES WITH COAL
''-^ IWANKICI

GRANITE &
\CRANITIC CNEISS
(INTRUSIVE)

GEOLOGICAL SECTION, BULAWAYO TO VICTORIA FALLS. 115

Yictoiia Falls. When you itfe standing' at the foot of the
Palm Grove, you will be able to count in the opposite wall of
the gorge five successive basalt flows. The amygdaloidal top
of one flow, combined with the amygdaloidal base of the
succeeding- flow, forms a band on the M'all of the gorge which
weathers differently from the more regularly jointed and more
massive central portions of each flow.

In the south-western corner of the Palm Grove gorge,
where the water of the Whirlpool dashes against the rocks,
may be seen what I take to be a small volcanic neck filled with
blocks of amygdaloidal basalt.

Before leaving the Karroo rocks, 1 wish to draw your
attention for a moment to the two sets of trough faults — one
at Inyantue and one at Lukosi — by which the Karroo rocks
have been let doAvn in long, narrow strips into the crystalline
rocks. These structures are, in fact, miniature rift -valleys.
The Lukosi rift-valley I have been able to trace for about
20 miles on each side of the railway. There is a third and
narrower rift-valley to the south-east of the others, which
passes under tlie Kalahari sand. It should pass beneath the
railway betAveen Maliudi and Dett, but as the Kalahari sand
here covers the older rocks to a great depth, I have not been
able to insert it.

The faults which formed these rift-valleys are almost
certainly of the same age as the Deka fault, and lend support
to the suggestion made some years ago by Mr. Molyneux that
the Victoria Falls basalts lie in a rift-valley, the north-
western edge of which is in Xorthern Rhodesia.

The Kalahari beds consist chiefly of loosely-consolidated
sand of a red or white colour, which, at Malindi, has been
proved by a borehole to have a depth of 240 feet. At the base
of the sand t.here is, in places, a bed of chalcedon^^ in which
Mr. Molyneux has found gastropods and fresh-water plants,
determined by Mr. E. B. Xewton, F.G.S., to be of uppermost
Cretaceous age. In places, too, at the base of the sand is a
bed of pisolific ironstone, which was formerly used by the
natives for smelting iron.

The Victoria Falls Hotel is situated on the edge of the
Kalahari sand, and at the foot of the sand-slope the chalcedony
crops out. The chalcedony nodules have been used by the
Bushmen for the manufacture of their stone implements, and
their working- sites may be found below the outcrop.

The section shows very clearh' the unconformable nature
of the Kalahari beds, and the gradual rise in the base of the
beds from ;''.,000 feet at the Victoria Falls to just on 5.000 feet
in the neighbourhood of Bulawayo. It also shows a
pre-Kalaliari valley of the Zambesi, but the tributary Matetsi
seems to have cut a new course for itself not along- the line of
the pre-Kalahari valley. The Kalahari sand is the formation
upon which the teak and mahogany forests grow, which you
will pass through between the toD of the scarp beyond
Nyaraandhlovu and T)ett, and again between Fuller and Kesi.

CRIME AND FEEBLE-MIXDEDXESS.

By G. T. Moeice, K.C. B.A

Read July IT, 1920.

The study of the mental deficiency called feeble-minded-
iiess is of great importance for the promotion of social welfare.
There is reason to believe that want of knowledge of this
matter leads to wasted effort and expense. The subject has
recently been receiving much atteution in England and
America. In South Africa, Dr. J. Marius Moll, of Johannes-
burg, has been a pioneer worker on the subject and has
endeavoured to rouse public interest in it. My object in this
paper is to draw attention to the bearing on criminal law of
the new light on the subject.

Advancing knowledge has shown chat the old broad dis-
tinction between sanity and insanity which prevailed in
criminal law was insufficient. About a century ago an English
Judge laid down that the insane person was one who was so
totally deprived of understanding and memory as to be as
ignorant of what he was doing as a wild beast. At the present
day no Judge would think of defining insanity in such uncom-
promiising terms. In fact, ever since McXaughton's case in
1843 there has been a controversy amongst English legal and
medical men as to what constitutes insanity in law. We know
the saying that there are no sharp distinctions in nature, an<l
this may be expected to ai)ply in a special manner to such a
subtle and complicated entity as the human mind. Medical
science is always tending to discover intermediate states between
the two classes which popular language distinguishes as the
sane and the insane.

In recent years much attention has been given to a class
of mentally defective person known as feeble-minded or
morons, wlioin one hesitates to place among either the sane or
the insane. Tliey are persons whose mind does not develop
beyond that of a child of twelve, and thougdi not without some
intelligence are incapable of looking after themselves, and
require, when grown up, supervision such as the normal person
only requires in his childhood. This class of persons has been
recognised in recent legislation dealing witli the insane. In
the Mental Disorders Act, i)assed in the T^nion in 191G, the
feeble-minded person is described as one " in whose case there
exists from birth or from an early ag? mental defectiveness
not amoimtiug to imbecility, so that he is incapable of com-
peting on equal terms with his normal fellows or of managing
himself and his affairs with ordinary prudence, and who
requires care, supervision and control for liis own protection
and the protection of others." The chief (diaracteristic of the
feeble-minded, so far as I can make out, seems to be want of
intelligence, accompanied by weakness of will, leading to the

CEIME AND FEEBLE-MINDEDNESS. 117

male driftiiig" into a life of crime or becoming" a habitual
drunkard, and to the female becoming- the victim of seduction —
tlie latter a lapse most calamitous for society, as feeble-
mindedness is hereditary.

Although the description of the feeble-minded given
above is rather vague, there can be no doubt that the medical
men and others who have studied the subject have laid their
hands on a real class of persons. Tests have been devised,
consisting of questions and exercises, in order to ascertain
whether persons belono" to the feeble-minded. These are
supplemented by the history of the person. Tlie upshot has
been, not only uniformity of results obtained by different
investigators, but also a singular agreement between the pro-
portion of the feeble-minded in various classes of persons in
different parts of the world. Thus, in 1904, the proportion of
feeble-minded (diildren in schools in England and Wales was
g'iven at "8 per cent., ratlier less than 1 in 100 ; and Dr. .T. Marius
Moll has arrived at the same figure for the Transvaal Govern-
ment schools, that is, for European children in the Transvaal.
This proportion of less than 1 per cent, may be taken as the
proportion of feeble-minded amongst ordinary adults of the
European race. On the other hand, the proportion of feeble-
minded amongst convicts (/.e., condemned criminals) has been
found to be about 20 per cent, both in England and in the
Transvaal. This means that the feeble-minded are more than
twenty times as numerous amongst convicts as among ordinary
persons, and the proportion increases with increased criminality
as measured by previous convictions or, lo'ng- sentences. I am
informed by Mr. Xorman. the able and zealous Probationary
Officer at Johannesburg, that in the case of first offenders at
Joliannesburg the proportion of feeble-minded was 8 to 10 per
cent. In industrial schools the proportion has been found to
be from 7 to 16 per cent., the proportions varying in different
schools. In reformatories the figures have ranged between
8 and 25 per cent. In contrast with those comparatively low
proportions, we find high figures for long-sentence prisoners.
Thus, at the Central Prison, Pretoria, the proportion was 20 ])er
cent. ; on the Breakwater at Capeto\>'n, 25 per cent, feeble-
minded and 10 per cent, cases on the border. In Sing Sing
Prison, America, Dr. Gluch foimd the proportion of feeble-
minded to be 28 per cent. In homes for fallen women and
amongst arrested prostitutes the pro])ortion of feeble-minded is
enormous. Dr. Dunstan found it to be 90 per cent, at the
Home at Irene, near Pretoria, and figures from other parts
of the world make this proportion quite credible. The high
proportion of feeble-minded is not confined to criminals. In
the case of an Unemployment and Relief Board, the proportion
of feeble-minded amongst those to be relieved was found to be
21 per cent.

It is clear from these figures that the question of feeble-
mindedness is of essential importance in dealing with
criminals. The credit of discovering this is due to the late
Dr. Goring, an English prison doctor, who, instead of pro-
pounding a high-sounding theorv about the criminal, like

118 CEJME AXU FEE15LE-MIXDEDXESS.

Lombrosa, followed the typical Englisli method of observing'
and recording- facts. Dr. Mercier, in bis book on " Crime and
Criminals," pnblished in 1918, somewhat depreciates the value
of Dr. Goring's work, and points out that his figures do not
apply to criminals generally, but to a selected class, namely,
those who are caught and condemned, who are presumably the
poorest of criminals in mental endowment. There is some-
thing- in this. But I think Dr. ^lercier lays too much stres.s
on it, and it seems to me tliat the high percentage of the
feeble-minded amongst convicts indicates a hig-li. thoug-h not
so high, a percentage amongst criminals, convicted and
unconvicted.

The question of feeble-mindedness has to be considered in
connection, first, with the trial, and, secondly, with the after-
trial treatment of criminals. In regard to the trial of
criminals, it is difficult to suggest any reform. It is true that
in the Mental Disorders Act of 1916 feeble-mindedness may
be said to be treated as a form of insanity. But mere insanity
is not a defence in criminal laAv. The crime must be the result
of insanity. In my opinion, the feeble-mindedness of a person
does not free him from criminal responsibility. It cannot be
said that the feelile-minded person does not understand the
nature of the criminal act which he commits, or does not know
that it is wrong', or that he suffers from delusions or acts under
an irresistible impulse: and those are some of the tests that are
applied when the defence of insanity is made.

It is quite true that in criminal law a child up to seven
years old is regarded as incapable of criminal intention, and
that fitom seven to fourteen years he is presumed to be
incapable of criminal intention, or, in other words, it must be
.proved that he knew the act was wrong. Thus the law might
take the position that the feeble-minded prisoner, having- the
mentality of -a child of not more than twelve years old, must
be presumed to be incapable of criminal intention. But thoug-h
this position is logical, I do not think it would be satisfactory
in practice.

Thus it would seem that the verdict in the case of the
feeble-minded who has r-ommitted a crime must continue to be
one of g'uilty. But feeble-mindedness should be looked upon
as lessening- the responsibility of the prisoner, as, in fact,
intoxication is looked on at present. "Where it is proved, as it
ought to be in the case of the prisoners who have already been
inmates of a prison, the sentence should be confinement in an
institution for the feeble-minded.

The after-trial treatment of a feeble-minded criminal
should undoubtedly be dift'erent from that of the normal
criminal. It is doubtful whether the severer forms of punish-
ment, such as whipping', spare diet, solitary confinement,
serve any g-ood purpose in the case of the feeble-minded.
Moreover, release from prison on the termination of a sentence
for a fixed period will in ordinary circumstances lead to a
relapse into crime. Separate places of confinement for
the feeble-minded are required, and special treatment.
Such places of confinement would involve an initial expense,

CRIME AXD 1-EEBLE-MIXDED>'E.SS. 11!>

but ill tlie long' run they might be found to be economical. The
feeble-minded are. I understand, easier to manage than normal
criminals, and M'ould thus require less supervision, and
probably more work could be got out of tliem.

In the recently published Eeport of the Director of
Prisons, he mentions that arraug'ements had been made for all
inmates of reformatories and all persons declared to be habitual
criminals to be examined by a psychiatrist (expert in mental
diseases). " Uiifortunately,'' he adds, " the shortag'e of
doctors at the mental asylums prevented these inspections
being" carried out before the end of the year, but I hope that
these will be possible next year." " The results of these
inspections,'" he says, '' should be of great assistance to the
administration, as undoubtedly there is an appreciable propor-
tion whose mental condition is below par, and who are not
only unsuited to the usual routine, but retard the progress of
the normal inmate."'

The Eeport only extended to the end of 1918. but I am
afraid the next year of which the Director speaks has gone
past without the inspections being completed, and, so far as
I know, they have not yet been completed.

Further, the Director probably only refers to European
inmates of reformatories and European habitual criminals.
]N^ow, it must be realised that these form only a small propor-
tion of the convicted criminals in the Union. The native
population of the Union is some five times as large as the
European population, and among the prison population is found
a still larger proportion of natives. Thus in 1918 the daily
average of persons in custody was 15,0GT'6, of whom 1,175 were
Europeans and 13.550 were natives and coloured, the
Europeans thus being- in a proportion of about 1 to 12 natives
and coloured persons. The fact of the g-reat majority of con-
victs being natives greatly increases the diihculty of the
problem of feeble-mindedness in this country. There can be
no doubt that feeble-mindedness is to be found amongst native
and coloured convicts. But how is it to be detected y The tests
applied in the case of Europeans are unsuitable, and satisfac-
tory tests have not yet been discovered. The great difficulty
is to find persons who understand the native and his language
and possess the special knowledge that enables them to api^re-
ciate feeble-mindedness. Here is a subject that calls loudly
for research. Possibly some of our missionaries will render
assistance in the matter.

In conclusion, I may refer to a point which is, perhans,
rather medical than legal. Feeble-mindedness is hereditary.
In the case of the offspring of the normal ])erson and the
feeble-minded, it folloM's Mendel's law. It is therefore of
the utmost importance that the feeble-minded should be
prevented from propagation. Segregation will prevent this to
some extent, but, in my opinion, any law dealing with
the subject should authorise sterilisation, subject to due
precautions.

ERICOID LEAVES.

By D. Thoday, M.A. (Cantab.),
Professor of Botany, Uni rcrsifj/ of Capefoini.

[Abstract.)

Read July 15, 1920.

A striking- feature of the Maquis of the south-west region
of Cape Colony is the hirge number of species with ericoid
leaves. These are characterised by a groove, either on the
upper or lower side, the stomata being- confined to the epidermis
lining the groove, which usually bears numerous hairs. In
contrast with tiie Maquis, the flora of the Karroo, if one may
judge from observations at Matjesfontein and Prince Albert
Eoad, lacks such plants almost entirely.

A feature of these plants which apparently has not hitherto
been noticed is that the grooves vary in the width of their
opening with changes in the conditions. If leaves are allowed
to dry up, they close their grooves, in many cases completely.
Even under natural conditions, during drought the leaves of
various species of Erica, of Passerina filifoTmis, of Stilbesp.,
have been found quite or nearly closed on plants in specially
dry situations. Under experimental conditions these species
close their grooves when left to transpire without water, and
open them again when supplied with water in a moist
atmosphere. Some species of Erica, especially E. Phihenetn,
also raise and approximate their leaves as they lose water, and
spread them again as their water content increases.

THE DISTRIBUTION OF ACCESSORY FOOD FACTORS
(VITAMIXES) IN PLANTS.

By E. Marion Delf, D.Sc, F.L.S.,

liesident Lecturer in Botany, Westfield College, University of London;

Temporary Lecturer in Botany in the University of Capetown; late

Yarrow Itesearch Fellow of Girton College, Cambridge; and Temporary

liesearch Assistant in the Lister Institute of Preventive Medicine.

Read Jahj 17, 1920.

Twenty years ago, when the rate of increase of the human
race led certain scientists to predict a total insntficiency of the
world's food supplies m the near future, Berthellot, a g*reat
French chemist, foretold that bread, meat and vegetables would
soon be replaced by food tabloids, a dinjier menu, tor instance,
reading : —

Small tablet nitrogenous matter.

Pastilles fatty matter.

A little sugar.

Seasoning.
It was indeed, until recently, a firmly established idea that the
necessary elements of a perfect diet could be obtained from
chemically pure carb(diydrates, proteins and fats, with a few
mineral salts. In 1912 liopkins found, when breeding rats on
an artificial diet of this kind, that the more perfectly purified
the constituents of the diet, the less were they able to support
life. Young rats ceased altogether to grow and older animals
grew thin and finally died when kept altogether upon chemically
pure foods, whereas the addition of minute amounts of fresh
milk caused an immediate improvement and an increase in body
weight altogether out of proportion to the increase of the food
intake of the animals. AYe now know that the addition of a
small amount of butter fat or of fresh green food would have
had a similar eftect. and it is abundantly clear that, in addition
to the recognised foods, small amounts of other unidentified
substances are necessary to health and are present in fresli
natural foods. These substances are known as vitamines or as
accessory food factors ; they are unstable under chemical treat-
ment and can be detected at present only by biological tests.
They have been the subject of much research in England and
America, especially since the increase of deficiency diseases in
Europe owing to improper and restricted diets' under war
conditions.

All the evidence points to tlie plant as the ultimate source
of these accessory food factors. Their distribution in the plant
world may be roughly summarised as follows: —

1. The Anti-neuritic Yitamixe (usmlly identified as the
water soluble growth factor).

122 IJISTRUfUTIOX OF VITAM1\ES IN PLANTS.

(a) Seed^ of Plants. — In pulses distributed throughout tiie
embryo, in cereals found in the embryo, and also in the aleurone
layer.

(b) Yeast Cells. — Preparations of dried or autolysed yeasts
are also rich in this vitamine. During the war, yeast cake was
extensively used for the treatment of beriberi, the specific form
of disease resulting from a lack of this vitamine. It is possible
that other edible fungi, such as truffles or mushrooms, might
be found to possess the same properties, but these have not been
tested.

2. The Anti-eachitic or Fat Soluble Growth Factor.

This is present in milk and butter fat as well as in certain
other animal fats and fish oils. The only vegetable oil which
has any appreciable value in this resjiect appears to be the oil
of peanuts (Arachis). It is also known to be present in a variety
of green leaves, such as lucerne, grasses and cabbage ; but the
result of recent experiments (as yet unpublished) prove that
the etiolated inner white leaves of an ordinary greeJi cabbage
contain no growth-promoting' properties. Fish oils, such as
cod-liver and whale oils, are especially rich in the fat soluble
vitamine, and it seems probable that the marine x\lg9e on which
these animals largely feed may provide the source of the
A'itamines in these products.

At the present time there is an unparalleled shortage of
the fat soluble accessory food factor in the civilised world,
especially in Central Europe, where this deficiency is the cause
of some of the terrible war diseases of these war-stricken areas.
Permanent improvement in these districts can only be expected
when either pasturage can be found for cattle or crops can be
grown for human consumption, but temporary relief could be
afforded by the much greater use of fish oils, since these are
usually cheaper to obtain than the relatively expensive
animal fats.

3. The Anti-scorbutic Vitamine.

There are two principal sources of this accessory food
factor, to which a third may now" be added as the result of
recent research.

(a) Vegetahles. — Many vegetables possess anti-scorbutic
properties,, especially in the fresh raw state. It has been
possible to grade vegetables roughly in order of their anti-
scorbutic value, and of all known vegetables, green cabbages
appear to be the most powerful in this respect. Many storage
organs, such as potato tubers, carrots and turnips, have also
considerable value, and there is some evidence which suggests
that their value is greater in the young than in the old con-
dition, and when freshly gathered rather than after prolonged
storage. French beans and beetroot have much less value than
the preceding, as may be seen from Table I.

There is a definite and considerable loss in anti-scorbutic
value when these vegetables are cooked, especially in water to

DISTiaJiUTIO-V Ol- V1TA:M1.V£S IX I'LAXTS. 12")

which soda has been added. In the latter case there is probably
little, if any, anti-scorbutic value left.

(b) Fritit.'i. — Various fruit juices have been quantitatively
tested, and of these oranges and lemon?^ are by far the best. A
young g-uinea-pig" receives a perfect diet if given oats, bran,
superheated milk ad Uhitiim, and orang-e juice to the small
extent of I'd c.c. daily. On this diet a reduction of the orang-e-
juice ration to 0'75 c.c. daily causes the onset of scurvy, and
the minimum protective value of the juice may- therefore be
taken as about 1 c.c. daily. Lemon juice (Citrus viedica var.
acida) g'ives a similar result ; but with lime juice (Citnts medica
var. liinoniiin) a ration of 10 c.c. (a higher ration could hardly
be tolerated) is scarcely sufficient to protect from scurvy. This
result has been obtained with many different samples of lime
juice, both freshly squeezed and preserved in different ways.
A number of confirmatory exjDeriments were carried out at
the Lister Listitute by Miss E. M. Hume on monkeys which
had been previously- kept for some weeks in the laboratory
in perfect health on a normal diet. During the experimental
l^eriod a similar diet was given, l)ut the only anti-scorbutic
which was supplied was a measured ration of lime or lemon
juice prepared and administered in the same way. In each
case a much larger ration of lime juice was needed to give
protection frcmi scurvy. In one case the lime-juice ration of
an animal which developed severe scurvy on a ration of 5 c.c.
of the juice daily was, when nearly at the point of death,
changed to 5 c.c. lemon juice of the same age as the lime
juice. The effect was almost immediate in reducing the
severity of the symptoms, whilst in the course of two or
three weeks the animal was completely cured. This case of
contrast between the effect of lime and lemon juice is the
more striking since there is practically no differeiice in the
chemical composition of the two juices.

Amongst other fruit juices, raspberry and tomato juices
may^ be mentioned as giving good protective results.
A variety of dried fruits have also been tested, and these
retain their anti-scorbutic properties to a slight extent.

(c) Gevminating Seeds.' — In 1912 a Swedish investigator,
Hoist, proved that whilst dry seeds of various kinds have
practically no anti-scorbutic value, when germinated for one
to three days they possess considerable value in this respect.
These results have been confirmed and extended in more
recent experiments at the Lister Institute. The seeds of
peas and lentils were soaked at laboratory temperatures for
about twelve hours, and placed in a funnel to germinate
covered with damp cotton wool. In two days (at about
60° F.) the radicles had grown to about 1 cm. in length, ami
in this condition they were used as the sole source of anti-
scorbutic in the diet of experimental animals. In the case of
young guinea-pigs, a daily ration of 2'5 gms. of these
germinated peas or lentils was found to give adequate pro-'
tection from scurvy. This may be compared with the cor-
responding ration of 1 to 15 gms. of fresh green cabbage leaf.

VJ4 insTRiJirTiox of vitamixes ix plants .

wliicli was found to be tlie corresponding' niiiiimuni i)rotective
ration under similar experimental condititms.

This result was published in a preliminary report in the
Army Medical Journal in 1918. In the followino- year, eases
of scurvy in prisoners of -Avar in the East were actually cured
by introducino' into the diet a ration of lightly-boiled
germinating- beans. The importance of this result to com-
munities cut off from supplies of fresh food is sufficiejitly
obvious. In this connection, it is of interest to find that in
parts of China it is a common custom to germinate beans
before eating them, and I have been told that in parts of
Africa the Kafhrs frequently germinate the corn for their own
•consumption. This would be of especial value in the winter
months, when for long periods no fresh food would be avail-
nble. It is doubtful how far the germination of corn in the
production of beers makes the drink of any anti -scorbutic
value. The commercial beers of the "West have been tested,
iind found to be worthless in this respect, but this may be
at any rate partly due to the high temi)eratures employed in
the drjdng' of the malted grain.

SuMilARY AXD GeNEEAL CoIs^CLUSIOXS .

The accessory food factors or vitamines are Avidely distri-
buted in the plant world, and are associated with definite
organs of the j^lant body.

Seeds possess the water soluble or anti-neuritic accessory
factor, but less richly than animal eggs. The embryo of all
seeds investigated and the germ of cereals contain it, but
the endosperm is probably lacking or nearly lacking" in this
respect. V^egetable oils have not been found to contain this
vitamine, with the exception of the peanut (Arachis). Xo
seeds in the dry condition have been found to contain anti-
scorbutic properties.

Gieen leaves possess both anti-scorbu1 ic and fat soluble
(or anti-rachitic) vitamines in considerable amount. The
former is a relatively unstable, and the latter a relatively
stable, substance. Green leaves probably form the cheapest
source of the fat soluble vitamine. The etiolated leaves of
the white " heart " of a cabbage possess anti-scorbutic, but
no growth-promoting properties. It seems probable, there-
fore, that the production of this vitamine is connected with
photosynthesis in the green leaf.

Storage organs (other than seeds) contain chiefly the
anti-scorbutic accessory factor, but to a less extent than either
fresh fruit or fresh green vegetables. Since, however, they
are easily grown and Avidely eaten, they are important in the
prevention of scurvy.

Succulent fruits contain the anti-scorbutic vitamine even
before ripening is complete. In this case the anti-scorbutic
vitamine appears to be more stable than it is in the case of
vegetables. The experimental evidence suggests that this
is not directly due to the acidity of the juice, but it may
perhaps be due to the fact that the vitamine appears to be
here of the nature of a reserve product.

DIMRIHUTIOX OF YITA:NJ1XES IX PLANTS.

125

Germinating' seeds liave considerable anti-scorbutic value
even before the appearance of any g-reen leaves. They have
also growth-promoting- properties. In this case the vitamines
seem to have been produced as the result of enzyme activity
in the g-erminating seed.

Yitamines may rlius be produced either in connection
with photosynthesis or in connection witJi tlie deposition of
reserves. In the latter case, the anti-scorbutic vitamine is
found in the living turgid cells of underground storage
organs or of succulent fruits, while the anti-neuritic vitamine
is found in the much drier dormant cells of the resting embryo.
Yeast is known to be rich in the anti-neuritic vitamine. but
other fungi have not vet been tested.

Table I.— DISTRIBUTION OF VITAMINES IN VEGETABLES
AND OTHER FOODS.

Water Soluble or

Anti-neuritic

Vitamine.

Fat Soluble or

Anti-rachitic

Vitamine.

Anti-scorbutic
Vitamine.

^Vheat Embryo

-f + +

■i +

Endosperm

Bran

-1-

Peas, Beans and Lentils (soaked'

! +

,, ,, (germinated

) +

+ +

rGreen

Cabbao;e - -^ ,, „

I \A hite " Heart"

+
+

-1- +

+ + +
+ +

Carrots (fresh)

•f

Runner Beans

Swede Juice

+ -r

Orange and Lemon Juice ...

-f -1-4-

Lime Jviice

+ or less

Tomato

+ +

Yeast

4- + +

Milk (fresh)

+ or less

Beef Fat

-1- +

Butter Kat

+ -;- +

Cod Liver Oil

+ + -r

Peanut Oil (Arachis)

THE LIFE-HLSTHEY UF THE AFRICAX SHEEP AND
CATTLE FLUKE. FASCIOLA GIGAMICA.

By A^-^-IE Porteu, D.Sc, F.L.S.. F.R.S. (S.A.),

Parasifologist, SoritJi African Institute for Medical Research,
Johanneshurg ; formerhj Beit Memorial Research Fellow.

Read Julii 15. 1920.

The occurrence of liver flukes in cattle and sheep has
been known for many years, especially in Europe. In South
Africa fluke infection of stock was also known, but it seems to
have been generally accepted that one fluke only, Fasciola
hepatica, the common European sheep and cattle fluke, was
present. Liver fluke disease, or " liver rot." becomes a disease
of importance economically when its action is accelerated by
such a condition as malnutrition due to droughts, or cold and
wet" seasons. However, the eradication of fluke disease is
possible, if the means by which the animals contract the
parasites is known.

It is well known that the larval stages of many flukes are
passed in snails. In South Africa two problems arose, namely,
whether more than one species of liver fluke occurred and what
was the transmitting mollusc. During my early investiga-
tions of larval flukes found in fresh-water molluscs suspected
of transmitting bilharziasis to man, I soon concluded that
several groups, as well as genera and species, of Trematoda
were present in two of the commoner South African molluscs,
Physopsis africana and Limnaea natalensis; for example.
Schistosomes, Echinostomes, Monostomes and strict Distomes
were all represented. I have also examined grass and other
vegetation from the banks of streams and ponds, and have
found the minute encysted larval flukes thereon. By^ experi-
mental work, using natural methods of infection. I have had
'the good fortune to elucidate, for the first time, the life-histories
of several of these organisms, among them being that of the
long, narrow African sheep and cattle fluke. Fasciola
gifiantica. This fluke is probably the indigenous cattle fluke
of South Africa. I may mention that my results were com-
municated and specimens exhibited to the Veterinary Research
Department at Onderstepoort in the latter part of 1919. and
were demonstrated, together with the life-histories of the
human bilharzial flukes and certain frog flukes, before the
Witwatersrand Branch of the British Medical Association on
December 18, 1919. A short account was published in the
Medical. Journal of South Africa, vol. xv, pp. 128-133, January.
1920. An exhibit was also given before the Roval Societv of
South Africa on March IT. 1920.

LIFE-ITISTOKY OF AVIUCAX LIVKR FLUKE. 127

A^ Fasciola (jifjanfica i^ widely clistrilaited in South
Africa, a summary of its principal features and life-liistory
is now given.

Fasciola (jiijanfica (("obbold, 185*]) is the large, narrow
liver fluke of cattle and sheep in South Africa. It was also
described under the apt name of F. angasta by Railliet in
18!)."). This fluke has been reported fronr certain big" game,
namely, giraffes, zebras and buffaloes. It has also been found
once in man. The larval stages of the fluke I have found in
the common pond snail, Liinuiiea nafaleiisis, and by experi-
mental work, using laboratory-bred rats, rabbits, <;uinea-i)igs
and sheep, I have been able to determine the entire life-history.
Also, by exposing laboratory-bred, and therefore uninfected,
Liinnaea natal en sis to tlie larvae (miracidia) issuing from the
eggs of F. ijiijanfica . the earliest stages in the snail have been
obtained.

In 191.), Dr. Cawstou described a distome cercaria from
Lininaea natalensis in the following words: " The other
encysting cercaria possesses a terminal oral and a median
ventral sucker. Xo eyespots could be detected. The head
of the cercaria is heavily pigmented, as are also the rediae
in which these cercariae are produced. These lediae are
three-eighths of an iindi in length, and whiten the liver sub-
stance of infected snails. The cercaria itself is fully a milli-
metre in total length. The rediae possess a well-defined oral
sucker and gut distended with particles of food. Towards the
posterior end of the rediae on the left side is a poorly developed
locomotor appendage." Cawston named the cercariae " C . pig-
inentosa in view of their pigmented heads." Unfortunately,
the description is insuflicient to enable the certain determina-
tion of the (.-ercaria, but I believe that the organism I used,
which developed into Fasciola gigautica, was the (' . pigmentosa
of Cawston. This may jjossibly be the same as ('. ohscara of
Sonsino.

xln outline of the structure and life-history of Fasciola
f/igantica, as I have observed it, is presented here.

When the liver of a Liinnaea natalensis infested with this
juirasite is examined, it appears to be streaked M'ith white
threads, which sometimes show orange to blaidv markings.
These threads are the rediae of F. gigantica, the intestines
of which contain orange to black contents. The rediae vary
in size with the season and the particular time of reproductive
activity of tlie fluke in the snail. The largest specimens were
about 12 mm. long, but this was quite excei)tional, the usual
size being from 1"5 to 2 mm. long. Daughter rediae appear
to be formed only towards the end of the life of the parent
redia. The parent redia produces several cercariae, Avliich are
active organisms, and A'ary in apjiearance according to their
degree of activity. The body of a cercaria measures about fiiW'i.
when fully extended, but when contracted it apiiears rounder,
and may measure only 250m. The tail is simple, and varies
in length from 159/i to 200/y.. The anterior sucker is fairly
pi'ominent, and the posterioi' one easily seen. The intestine

128 LIFE-IIISTORY OF AFEICaX LIVER FI.VKE.

forks into two jnst above the posterior sucl^er. In life the body
is crowded with masses of cystogenous granules contained in
unicelkdai cystogenous glands, which cystogenous granules
(" pigment " of Cawston), together with yolk, largely obscure
the finer details of the organisation.-

When an infected snail is isolated in water, the cercariae
readily leave it, and can just be seen with the naked eye swim-
ming actively in the water. After a time they leave the water and
creep up the stems of any plant in their vicinity. Each cercaria
commences to extrude the cystogenous granules from its V)ody,
and soon casts its tail. The body then contracts into a spherical
mass, surrounded by a cloud of granules forming a viscid coat.
These gradually condense and form a thick cyst wall, which
hardens on exposure and contracts somewhat; they measure
-loOu lo 650/x in diaiueter. The encysted cercaria shows its
two suckers, forked gut, genital rudiments and the remains of
the cystogenous granules. The encysted cercariae on herbage
by the waterside are in favourable situations for ingestion by
any herbivorous animal, such as ox, sheep or buffalo. I may
mention that from one infected Linniaea nataJensis I have
obtained 1,070 perfect cysts, and several hundreds are usually
produced from an infected snail.

Jiy direct experiments of feeding- herbivorous animals
(sheep, rabbits and guinea-pigs) and omnivorous animals (rats,
mice) on green barley and cabbage contaminated with cysts of
('. jngmenfosa, I have succeeded in obtaining adult flukes
corresponding with the adult Tremaiode, Fasciola gigantica
of Cobboid. These adult flukes varied in size, large ones being
55 mm, long and up to 9 mm. broad, while small specimens
were about 20 mm. long. Sexually immature forms were also
present in my experimental animals, varying from 5 mm. to
10 mm. in length and in breadth from 2 mm. to -1 mm. The
sides of the body are nearly parallel, and the cephalic cone is
short. The anterior sucker is distinct, about 1 mm. in diameter;
the posterior sucker (acetabulum) is prominent, and in large
specimens reached 1"8 mm. in diameter. The genital pore is
situated just above the anterior margin of the acetabulum, and
the intromittent organ often protrudes from it. The pharynx
is well marked, the oesophagus short, and the numerous lateral,
branching intestinal caeca are directed slightlv backwards.

The reproductive system consists of two testes, placed one
behind the other and much branched. Each has a vas deferens,
and the vasa deferentia unite anteriorh'. The ovary is rela-
tively small and is branched. The uterus and oviduct are
convoluted. Yolk glands are present and are greatly branched.
Tlie vitelline ducts are readily seen, and the transverse junction
is dilated centrally into a vitelline receptacle. A large shell
gland is present. The eggs are large, measuring about lT5u
long and 85/x broad.

Typical experiments that I made in connection with tlie
elucidation of the life-history of Fasciola gigantica may be
briefly summarised. Thus, a rabbit was feci with green food
contaminated with cysts from Limnaea nataJenxis. It gradu-
allv became emaciated, and died (\X davs after the infective

I.TFE-lllSTOKY 01- AFEICAX LIAER FLUKE. 12D

feed. At post-moitein over 20 adult flukes were obtained from
its liver, which was enlarged, had much thickened bile ducts,
and showed maiked disinteo-ration of its capsule. Recent
haemorrhag'es into the connective tissue around the terminal
part of the rectum and lower part of tlie abdomen, together with
a haemorrhag'ic sac betweeu the deep and superficial muscles
of the thigh, were present, and these haemorrhages contained
one or more Hukes.

Similar results were obtained with a guinea-pig. which
died 74 days after the infective feed.

A young sheep, bred from and belo'iging to a stock known
to be free from liver fluke, was fed with green barley con-
taminated with encysted cercariae from Litnnaea natcdensis,
two such feeds being given. On the first occasion only a few
cysts were available; on the second, about 250 cysts were
administered. The animal died 143 days afler the first and
11!> days aftei' the second infective feed, and 22o adult flukes
were recoveied from it at autopsy. Sixty-four days after the
second infective feed the animal was noticed to be less active
and to lie about a good deal. This behaviour continued at
intervals until it died. For seven days prior to death most of
its food was refused, but it ate its mash and some green barley
on the day previous to death. At post-mortem the body
appeared well nourished. The liver showed marked perilie])a-
titis, was greenish in colour, with numerous blackish
haemorrliag'es. There was slight oedema. The bile ducts were
greatly thickened and fibrotic. The intestines were heavily
bile-stained, and contained some flukes in the canal, which also
showed many small haemorrhages. All the blood-vessels of
the mesentery were engorged. A small haemorrhage beneath
the skin near the anus contained one fluke. The organ most
affected was the liver, from which 189 flukes were recovered.
The bile ducts were blocked in some places with tangles of two
or three flukes.

Similar experiments were performed, using rats and mice,
with similar results. The minimum time before adult, sexually
mature flukes have been obtained experimentally has been
(i4 days.

The eggs of Fasciola (////aiificd do not hatch leadily under
experimental (conditions, and my experience has been that they
take from 11 to 54 days Isefore the miracidia emerge. Direct
infection of laboratory-hred Limnaea nofalensis with the mira-
( idia of F. (/if/(tntir(i has been carried out, so that the complete
develt)i)niental cycle is now demonstrated.

FdscioJa f/if/anfica is fairly widely distribaited in South
Africa. Tlius, following on my communication to the
Veterinary Research Division in 1919, the i]wv Actina-
Director. Mr. D. T. Mitchell, sent to a well-kiiown " fluke ""
district in the Transvaal, and it was found that sheep and oxen
there were parasitised with F. f/lfjanficd, not F. hepafica, as
had been thought. Similar finds wej-e made in Swaziland.
F. r/if/anfjca has since been reported from several Transvaal
localities, and I have found it fairl.\ commonly in the livers of
cattle condemned for fluke in th'^^ Joliannesburg abattoirs.

130 LIFE-lIISlOP.y OF AFEICAX LIVER FLUKE.

where it is almost as common as F. hepaiica, and mixed
infections of the two flukes occur. Specimens have also been
obtained by me from Xatal, from the Eastern ProA-ince and the
Western Province of the Union of Sonth Africa, and from cattle
sent from Rhodesia.

With regard to preventiye measures, the following pre-
cautions are sug-o-ested : Where Limnnea nafalenais occurs,
vegetation should be reduced to a minimum at the edges of
the ponds and streams, and reeds and bulrushes should be cut
back. These plants are favourite jilaces for breeding and the
food for choice for the snails, and their absence is therefore a
deterrent to the spread of fluke. The Limnaea also feed
greedily on the leaves of the blue water lily, on the underside
of whose leaves they lay their egg- masses.

Cattle and sheep should be kept from damp, marshy soil,
where Limnaea is present in the water. I have found infected
snails twenty feet from the edge of the water in marshy spots
in Xatal. AVatering of stock with water that has been stored
for two days is almost sure to be safe. The cercariae of Fasciola
(jijjantica rarely suivive more than thirty-six hours in water,
and unless there are facilities, such as grass or debris on which
they can encyst, they either i)erish or else they encyst on the
sides of the storage tank, just above the level of tlie water. The
cysts are not easily washed off when water is drawn, but can
be scoured or scraped oft^ and buraed when the tank is empty.
The latter precaution of burning is necessary, as the c^^sts
remain alive for considerable periods.

Some recent experiences and observations in the open have
shown me that ducks are very efficient in destroying pond
snails, and, in the absence of the necessary molluscs, the life
cycle of the parasite fails. It is possible that the ducks may
transport the eggs of the snails from one pond to another, but
it seems to me that the danger therefrom is i>m^-h Ip-^' than that
due to the presence of the snails, nil kinds of which are greedily
devoured bv the ducks.

SOME PAEA8ITIC PEOTOZOA FOUXD IN
SOUTH AFEICA.— III.

By H. B. Fantham, M.A. (Cautab.), D.Sc. (Lond.),
Professor of Zoology, Universitij College, Jolianneshiirg.

(Ah^fract.)
Read Jul !i 15, 1920.

The present communication forms a continuation of pre-
ceding ones made at Annual Meetings of tlie Association in
1918 and 1919, and published in this Jouexal, vol. XV,
pp. 337-388, and vol. XVI, pp. 185-191. Preliminary accounts
only are given, as the work is being continued, and it is hoped
to publish fuller, illustrated accounts later, after more extended
study. This record, however, contributes to our knowledge of
the distribution of the parasitic* Protozoa.

Attention may, be drawn to two points, the finding of
seasonal variation in the occurrence of Sarcosporidia, and the
presence of several genera and species of Ciliata in the digestive
tracts of various Ungulata.

The term " parasitic " in the title is used in a wide and
general sense; some of the organisms described may prove to^
be saprozoites and some may be commensals.

Sarcodixa.

Few additional Protozoa belongin.g to this class liave been
seen by me since my last report. On two occasions a few
amoebcTe have been found in the colon of horses at Onderste-
poort. These are probably specimens of Amadxi [E/ifdmwba)
intestinalis mentioned by Gredoelst (1911)* as occurring
normally in the intestine of the horse. The making of
I^ermanent preparations Avas difficult, as the infections were
very scant}'.

MASTIGOniORA.

The blood of some " field-mice," Arrianithis pumilio,
caught in the neighbourhood of O