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2OU RN AL
OF THE
ROYAL HORTICULTURAL SOCIETY
EDITED BY THE
REY. W.) WILKS; M.A.
SECRETARY
Mi OL Re
bybrid Conference Report
1900
LONDON
Printed for the Royal ‘horticultural Socicty
BY
SPOTTISWOODE & CO., NEW-STREET SQUARE, E.C.
Fie. 124.—Lmuio-Carrreya Apuroprre Ruts. (Journal of Horticulture.
(CarrneyA Mrenpreni x L&x1A PURPURATA.,)
4 LY Ae
wy
AI cal aM
? NEW Yorn
BOTANICAL
VAR DEM:
a
Ceernt Ss OF VOL. “XXIV.
HYBRID CONFERENCE REPORT.
ARRANGEMENTS OF THE CONFERENCE ........... pobrgsseanEecen Aoeee Aabtaiaisarstenseies sonsec
PRINCIPAL PLANTS EXHIBITED .................. SoA CoceaCteneee PRA CPR AD AU DLS OROCEECE Rides bored
PAU secu TN EIT NGA Tea OTIS WIC Kan eeiiert-ielaeelosialsleiedleledaieiteie aie ocltelsolnismia es sleciisasisrasels(nsiesie coe
THE Banquet at THE HOTEL METROPOLE ........... {qobnogadaacaese Mende ssaaeeacoaredas
Inrropuctory Appress. By Dr. M. T. Masters, F.R.S. ........eceeeeee seBAeE conc ae
Hypripisation As A Mernop or Screntiric Investicarion. By Mr. W.
SATE ONG VEGAN 9H EUsSen csivca's dis tan cieistiasiainiecnes Des Star ietalclatte sls wets ive sisiers actstia'desieras als
FERTILISATION oF ANTHURIUM. By Monsieur DE La DEVANSAYE ......... sndonose noe
Hysrivisinc Monsrrosrries. By Professor HUGO DE VRIES............-0eceeeeeree ees
HYBRIDISATION AND ITs Famures. By the Rev. Professor Grorce HeEnstow,
ish, OS aE ee Ae a a Pe een avaec wei tcaaeiineicesisdescciseriaasena + Socodeonnd
EXPERIMENTS IN Hysripisation. By Mr. C. C. Hurst, F.L.S. ........... Spagducoor
THe Untrep Srares DEPARTMENT OF AGRICULTURE AND Hysripisation. By
Mrs HERBERT J.) WEBBER c.cceco.decdsccecoseeccusersseued eeeatases cochne debnOBDDeS
THE SrrucTtURE oF soME NEW Hyprips. By, Mr. Joun H. Winson, D.S8ce.,
MEET Se anes cto e'- aeeng fa lee gets sin cnieicetoitaids s SyERCI A+ oe pose aCs Bestaerantlncene steamers
HYBRIDISATION AND Systematic Borany. By Mr. R. Auuen Roure, A.L.S. ......
HYBRIDISATION IN THE UNITED States. By Professor L..H. Barney ...............
On Setr-srermity. By Professor Dr. Lupwia ............ dob a500c BOSS Palesaae Ssachoce
CROSSINGS MADE Av THE Natruran History Museum ar Paris. By Monsieur
ESELENRY: fe. e.c.00%'- SophOCHnEOonncagsceHCnoTOhecceboos Andon daEnoBananeposode spcreisiete's cise sc
SeeGeAnt FiveRmDs. By Monsieur: TH. JOUIN- .......cccccecscecetacseccccscscecseceane “0
On Hysrip Drosera. By Professor J. MurrHeap MacFaruann, D.Se. ..........05
Kucatyptus Hyprips. By Dr. Trapur ................ sbatlodbe Seo ochuacneaee Eanes Sao0toc
ON THE INFLUENCE OF EITHER PaRENT. By Dr. L. WITTMACK ........0ceeceeeeeees
A Frew Genera Principtes. By Herr Max Letcurui......... sobocSt spn SOC HeBCRDOCEE
BREEDING Foop Puants. By Professor WILLET M. HAys ......cssccecseceeecenees -
On THE Use or Transparent Paper Baas. By Professor Huco pe Vries ......
Hysrip Crnzrarias. By Mr. R. Irwin Lynch ............ccceeeee danaicejemsecaemes cassis
Arrempr To Improye Crocus sativus. By Monsieur Paut CHAPPELLIER .........
Hysrip Dioscornra. By Monsieur CHAPPELLIER ............sscsceeeeneeeeeees Sehognnoehee
Hysprip Mrrasitis. By Monsieur CHAPPELLIER .......0.cccseceeesscuenceceneeeeeesenees
IvproveMeNT oF Harpy Prants py Hysripisinc. By Dr. Coartes Stuarr......
man, Hyspins. “By Mei i Drumry, BeliS), VeMiE. .2.1....cc0ncecesscenscreeeee ‘
Fern Hysrivs. By Mr. H. B. May .
146
181
209
214
218
237
241
250
252
256
257
266
269
275
278
279
280
288°
298
ll CONTENTS.
Hysrip Linacs. By Monsieur BE. LEMoIne ...............6.. cece
Y
Hysrip Ciematis. By Monsieur F. Moren....... Sanevieawelisore Janta ate eee eke
Hyprip Crematis. By Mr. A. G. JAcKMAN ..............- SHAOI0C
ANTHURIUM SCHERZERIANUM. By Monsieur Dvvat ....
Brometriaps. By Monsieur Dtvat ........ Beets miele cits Ach seiete sot sa ais ceaSeenene Rete
GUOXINIAS: By MonsicUrMDUVAL, 0.5. 0:.0c0cccccrcescoreecsescees Soaeisicdines tees see ance
NorEs on some Hysrips. By Mr. ToHomas MEEHAN ................06- SAUD, =
CHRYSANTHE MUMS egy ANU eels WV) DK SmR cic is weiss scriels cise ccieneced vasecees aaaieckeeeee cee
Fucusias. By Mr. James Lyr........... euan couse :
Nores on some Hyprips. By Mr. W. SuyrHe ..... cies Riottnck Coan oe coe ReRe
Notices To FELnows....... Spice ences Prasastes on ae
INDEX? Sacto. coca sen EM a erate sitisiiire cisiaciacian sole anctmeaiet
ADVERTISEMENTS.
315
323
326
337
339
341
343
344
B47
at)
JOURNAL
OF THE
RoYAL HORTICULTURAL SOCIETY.
Vou. XXIV. 1900.
HYBRID CONFERENCE REPORT.
Tue Council of the Society having decided in the Autumn of 1898 to hold
a Conference on Hybridisation in July 1899, the following Schedule was
drawn up and issued in January 1899. It is reprinted here in full, as
being of some historical interest, and also because it may prove suggestive
for any future similar meetings :—
Roval Hortic
[fural Societn.
Banat, Soe NS Incorporated
ne
Established
A.D. 1804. SPE: we A.D. 1809.
INTERNATIONAL CONFERENCE.
LSOoo:
Tuesday, July I1th, at Chiswick,
Wednesday, July 12th, in London.
On Hybridisation (the Cross-Breeding of Species) and on
the Cross-Breeding of Varieties.
COMMITTEE OF ARRANGEMENT.
F. W. BursipGe, M.A., V.M.H. F. G. Luoyp, F.R.H.S.
Srr Winuiam THIsELToN-DyeEr, Maxwett T. Masters, M.D.,
K.C.M.G., F.R.S. F.R.S.
JAMES Douguas, V.M.H. T. J. BENNETT-Po#, F.R.H.S.
Rev. G. H. En@neneart, M.A. | CuarnEs E. Sua, F.R.H.S.
Rev. ProressorG. Henstow, M.A.,| Harry J. Verroen, F.L.8.
V.M.H. Rey. Wivu1am Wiss, M.A., Sec.
JAMES Hupson, V.M.H. R.H.S.
B
2 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Nove.
All plant-growers, whether amateurs or nurserymen, are particularly
requested to exhibit Hybrid or Cross-bred Plants (whether in bloom or
not), with their parents, at the meeting of the Conference at Chiswick on
Tuesday, July 11. All plants should arrive at the Society’s Gardens at
Chiswick at or before 11.30 A.m., and may be removed at 5 p.m.
The ordinary Committees of the Society will meet at Chiswick on
Tuesday, July 11, at 12 punctually, and plants, &c., for Certificate will be
placed before them as at the usual meetings in the Drill Hall, but with
the exception of plants, &c., for certificate, and hybrids and their parents,
no other plants, &c., may be exhibited on this day.
TUESDAY, Juny 11TH (Cutswick).
Cass
1. New and Rare Plants and Flowers. Open . . Certificates.
2. New and Rare Fruits and Vegetables. Open . . Certificates.
Any New or Rare Plants, &c., may be shown for Certificate
exactly in the same way as at the Drill Hall.
N.B.—The Exhibition of Hybrid and Cross-bred Plants, whether in blossom or
not, is specially requested, with their parents if possible, and a written
account of the origin of the Hybrid; but with the exception of Plants,
&c., shown for Certificate, none but such specially indicated plants may
be shown. No Groups or Miscellaneous Exhibits. Other Awards will
be given to Exhibits of Hybrids, but the following are specifically
offered :-—
3. A Veitch Memorial Medal to the raiser of the best new Fruit
intentionally raised by cross-breeding or hybridisation in Great
Britain, and never previously exhibited.
4. A Veitch Memorial Medal to the raiser of the best new FLOWER
(Orchids excluded) intentionally raised by cross-breeding or
hybridisation in Great Britain, and never previously exhibited.
. A Veitch Memorial Medal to the raiser of the best new Orcuip
intentionally raised by cross-breeding or hybridisation in Great
Britain, and never previously exhibited.
6. A Veitch Memorial Medal to the raiser of the best new VEGETABLE
intentionally raised by cross-breeding or hybridisation in Great
Britain, and never previously exhibited.
7. A Veitch Memorial Medal to the raiser of the best new Fruir
intentionally raised by cross-breeding or hybridisation out of
Great Britain, and never previously exhibited.
s, A Veitch Memorial Medal to the raiser of the best new Frowrr
(Orchids excluded) intentionally raised by cross-breeding or
hybridisation out of Great Britain, and never previously
exhibited.
9, A Veitch Memorial Medal to the raiser of the best new OrcHrD
intentionally raised by cross-breeding or hybridisation out of
Great Britain, and never previously exhibited.
10. A Veitch Memorial Medal to the raiser of the best new VeGETABLE
intentionally raised by cross-breeding or hybridisation out of
Great Britain, and never previously exhibited.
Or
oe
HYBRID CONFERENCE REPORT. 3
The above Medals will only be awarded should the exhibits be con-
sidered sufficiently meritorious, and the result of intentional, not
accidental, cross-fertilisation.
Exhibitors must give Fruit details in writing as to parentage, and
record any other points which may assist the Judges.
11. A Williams Memorial Medal to the best collection of Hybrid and
Cross-bred PuaNnts.
MEETINGS.
12 noon. Fruit, Floral, and Orchid Committees meet.
12.45. The President of the Society, Sir Trevor Lawrence, Bart.,
V.M.H., will receive the invited Members of the Conference.
1 P.M. Luncheon.
2.15 p.m. Conference on Hybridisation and Cross-breeding.
5.0 P.M. Conference adjourns.
6.0 for 6.30 p.m. The Foreign Members of the Conference will be
entertained at dinner on the kind invitation of the Horti-
cultural Club, under the presidency of Sir John D. T.
' Llewelyn, Bart., M.P., at the Hotel Windsor, Victoria
Street. Morning Dress.
WEDNESDAY, Juty 12TH (Westminster Town Hatz).
MEETINGS.
2.0 p.m, Conference continued at Westminster Town Hall.
5.0 p.m. Conference concludes.
6.30 p.m. Reception of Guests by the President of the Society and
( Lady Lawrence at the Whitehall Rooms, Hotel
| Métropole.
7.0 p.m. Banquet of the Society. Evening Dress. All Fellows can,
as far as space will permit, obtain tickets (price 21s.
each) for ladies or gentlemen, by applying (with cheque
or postal order) to the Secretary, 117 Victoria Street,
before July 5th.
The following arrangements are subject to alteration :—
TUESDAY, Juty 117TH, at CuHiswick, at 2.15 p.m.
1. Introductory observations.
Maxwell Masters, M.D., F.R.S., London, Chairman.
2. Hybridisation and Cross-breeding asa Method of Scientific In-
vestigation.
W. Bateson, Esq., M.A., F. R.S., Cambridge University.
3. Hybridisation as a means af Pingenetic Infection.
Professor Hugo de Vries, Amsterdam University.
4. Hybridisation and its Failures.
The Rev. Professor Geo. Henslow, M.A., V.M.H., London.
5. Progress of Hybridisation in the United States of America.
Professor L. H. Bailey, Cornell University, Ithaca, U.S.A.
6. Experiments in Hybridisation and Cross-breeding.
C. C. Hurst, Esq., F.R.H.S., F.L.S., Burbage, Hinckley.
B 2
4 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
WEDNESDAY, Juty 127TH, at THE Town Hatt, WESTMINSTER,
AT 2.15 P.M. E
. Introductory observations.
Sir Michael Foster, K.C.B., Sec. R.S., Charrman.
2. Work of the United States Depatemcnl of Agriculture in Plant
Hybridisation ; with Lantern Demonstration.
Herbert J. Webber, Esq., Washington, U.S.A.; Special Envoy
from the United States Department of Agriculture.
8. The structure of certain New Hybrids (Passiflora, Albuca, Ribes,
Begonia, &c.); with Lantern Demonstration.
Dr. J. H. Wilson, F.R.S.E., St. Andrews University,
Scotland.
4. Hybridisation viewed from the standpoint of Systematic Botany.
R. Allen Rolfe, Esq., The Royal Gardens, Kew.
. Hybrid Poppies.
Monsieur Henry de Vilmorin, F.R.H.S., Verrieres, France.
6. Self-fertilisation of Plants.
Monsieur Lemoine, F'.R.H.S., Nancy, France.
. Hybrid and Cross-bred Fruits.
Luther Burbank, Esq., San Rosa, California, U.S.A.
T. Francis Rivers, Ksq., V.M.H., Sawbridgeworth.
8. Hybrid or Cross-bred Irises, Begonias, Chrysanthemums, Cinerarias,
Rhododendrons, Clematis, Fuchsias, Violas, Gladiolus, &e.
Sir Michael Foster, K.C.B., Sec. R.S., Monsieur Crozy, Messrs.
J. Laing, V.M.H., Chas. E. Shea, W. J. James, F. G. Waterer,
Harry J. Veitch, A. G. Jackman, J. Lye, G. Yeld, J. Heal,
V.M.H., Monsieur V. Lemoine, and Dr. Stuart have been
invited to supply short papers on these subjects.
Papers have already been promised by Monsieur Duval on Gesneriacez,
Anthurium, and Bromeliacee ; by Dr. Stuart, on Violas, &c.; by Mr. A.
G. Jackman, on Clematis; by Mr. Charles T. Druery, V.M.H., on Ferns ;
by Monsieur Truffaut, on Bromelias; by Monsieur de la Devansaye, on
Anthuriums; by Mr. James Lye, on Fuchsias ; by Mr. William Smythe,
on Cross-breeding; by Professor Ludwig, on Self-fertilisation ; by Mr.
T. Meehan, on Hybrids; by Heer Krelage; and by Mr. George Paul,
WeNinels”* pé,
The writers of Papers are requested to give all the information
possible ; and those who are able to be present in person are requested
to give an epitome of their arguments, or to mark off portions of their
Papers which can be read within a limit of from 20 to 30 minutes.
The final selection of the Papers to be read at the Meetings and their
order must be determined at the time, and will be left to the discretion
of the Chairman and Committee ; but all the Papers will be printed in
full in the Society’s official report of the Conference.
All MSS. in a foreign language should be sent to the Secretary at
least 10 days before the Conference that they may be translated in
readiness.
Amateurs, Nurserymen, and Gardeners are requested to send exhibits
of True Hybrids, and of any plants known to be of ecross-bred origin ; also
of Graft Hybrids; for exhibition at Chiswick on 11th.
—"
On
~1
HYBRID CONFERENCE REPORT. 5
In order that accurate results may be arrived at, and to facilitate com-
parisons and deductions, a card (as shown) will be supplied to all
exhibitors on application, which it is requested may be carefully filled up
with all the necessary details. When either the seed or pollen Parents,
or both, are themselves cross-bred, it is particularly requested that the
pedigree may be given through as many generations of ancestors as
possible. Exhibitors are most earnestly requested to apply for their
cards beforehand, and to fill them up accurately and legibly. Each
separate plant should be entered on a separate card so as to avoid con-
fusion—only one plant on one card.
Anyone who will be so kind as to send plants or cuttings of Hybrids
to be grown at Chiswick in readiness for the Conference will receive the
best thanks of the Council.
SPECIMEN OF CARD (Reduced).
HYBRID OR CROSS-BRED PLANT.
Raised by Mr. ........ BeReeg es seen ces’ BUCLOUECSSecabe eee cious eee a ,, Phillyrea.
a. Osmanthus ; : ee » Phillyrea.
a. Rhaphicfepis 4 ,, Crateegus Pyracantha.
a. Crategus . < 5, Quince.
a. Kriobotrya a ,, Rhaphiolepis.
b. Eriobotrya . - » Quince.
a. Choisya. : . eh yee » Skimmia.
b. Amelanchier . ; Ae , Thorn. —
a. Phillyrea . ; . ms », Olea.
b. Pyrus japonica . ' Pl ,» Quince.
b. Rosa Wichuriana variegata __,, ,, Rubus.
a. Eleagnus . ; 5 Sl eee ,, Hippophaé.
a. Cupressus nutkaensis . fe et ,, Biota orientalis.
c. Kalmia , ‘ 4 a abe ,, Rhododendron.
a. Phillyrea . ; ; ney ,, Osmanthus.
a. Doing well. b. Doing fairly well. c. Doubtful.
THE LUNCHEON. 39
After the Exhibition a luncheon was given by the Council, to which
all whose names appear on pp. 6-8 were invited, together with all the
members of the Scientific, Fruit and Vegetable, Floral, Orchid, and
Narcissus Committees; Sir Trevor Lawrence, Bart., President of the
Society, being in the chair.
Luncheon ended, the President rose and proposed the toast of Her
Gracious Majesty the Queen, Empress of India, patron of the Society.
The toast was received with acclamation and drunk by all upstanding.
The President again rose and said: Ladies and Gentlemen,—I am sure
that we, none of us, wish that the proceedings of the Conference should
be delayed by speech-making, but there is one thing that I cannot deny
myself the pleasure of doing, and it is this: on behalf of the Royal
Horticultural Society to tender to all our friends who have gathered
around us to-day, and especially to the gentlemen who have travelled
from abroad on purpose to join in our Conference, a most hearty greeting
and a most hearty welcome. I am sure that we are very grateful to
those foreign friends whom we see around us, distinguished in horticul-
ture and in botany, for their presence here to-day. We know that they
have come at great expense and at no little inconvenience to join in our
deliberations because, like ourselves, they are devoted to the science and
the art of gardening. And we, we haye been obliging enough to provide
them with an almost tropical temperature, so that I do not think that
when they go back to their own countries, even though they be countries
ordinarily warmer than our own, they will any of them have cause to
complain of any lack in the warmth of our reception. In this country,
rightly or wrongly, we manage things somewhat differently to the way
in which they are managed abroad. When we go abroad to gatherings
of this sort we receive the most cordial and friendly—I might say the
most magnificent hospitality at the bands of our horticultural friends ;
and this hospitality is extended to us not only by them but by the
municipalities and by the Governments of the countries where the gather-
ings are held. I hadthe honour of being a Member of the House of
Commons for several years, and I venture to wonder what would happen
if I were to ask the Chancellor of the Exchequer to give the Royal
Horticultural Society a grant to enable it to entertain its distinguished
visitors in a due and worthy manner. I know very well what the result
would be. But I am sure that, notwithstanding the unavoidable dis-
advantages of our position, no more cordial weleome could be extended
to our foreign friends in any country than that which every Fellow of
the Royal Horticultural Society now desires to convey to them through
me. I hope therefore that our distinguished visitors will accept our
apologies for all defects in our arrangements, and will make allowance for
any shortcomings they may discern, resting assured that our one hope is
that they may carry home with them such a sense of the sincerity of our
British welcome as may induce them to give us the pleasure and the
honour of seeing them again amongst us on many similar occasions.
Asa proof of the cordial feeling entertained by our foreign friends for
the horticulturists of this country I may mention that a letter has this
moment been received announcing that it has pleased His Majesty the
King of the Belgians to bestow the high honour of the Insignia of an
40 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Officer of the Order of Leopold upon our distinguished friend Dr.
Maxwell Masters, F.R.S., who is to take the chair at the first session of
our Conference to-day. ;
The announcement of the honour conferred on Dr. Masters came as
a complete surprise to all present, and was received with continuous
rounds of cheering and applause.
After the luncheon the first session of the Conference was held in a
marquee on the lawn. (See p. 55.)
In the evening the foreign and distinguished guests were entertained
at dinner, at the Hotel Windsor, Westminster, by the members of the
Horticultural Club, under the presidency of Sir John D. T. Llewelyn,
Bart., M.P. The dinner was of an informal nature, and was thoroughly
appreciated by all present. The guests were delighted by the friendliness
and enthusiasm of the greeting given them, one foreign Professor
remarking that the dinner reminded him of his student days at the
University, and that he had no idea the English could unbend so far ;
another writing afterwards, “‘ As long as I am alive I shall remember
that dinner at the Horticultural Club.”
The heartiest thanks of the Royal Horticultural Society are due to
the Horticultural Club for providing so enjoyable an evening for the
Society’s guests.
The second session of the Conference was held on Wednesday,
July 12, at 2 p.m., at the Westminster Town Hall. (See p. 127.)
In the evening a grand banquet was given by the Society to all the
members of the Conference at the Whitehall Rooms of the Hotel
Métropole. The tables were most beautifully decorated with a profusion
of the rarest and most exquisite flowers presented by Messrs. Cutbush,
Laing, G. Paul, W. Paul, Sander, Turner, and Veitch. The thanks of
the Society are due to these gentlemen, but more especially to Mr. James
Hudson, V.M.H., who devoted the whole day to arranging them, and also
contributed all the beautiful hybrid Water-lilies which were so universally
admired. The magnificent fruit was contributed by Mr. Geo. Monro,
V.M.H. Itis due to both of these gentlemen to record that the authori-
ties of the hotel bore witness that they had never in all their experience
seen such a wealth of flowers and fruit, or any so beautifully arranged.
Covers were laid for 180, and, besides the foreign and distinguished
members of the Conference (see pp. 6-8), the guests included His Excellency
the Belgian Minister, His Excellency the Netherlands Minister, the Right
Hon. Lord Justice Lindley, Master of the Rolls, the Right Hon. the Earl
of Annesley, Sir Edward Fry, J. Rutherford, Esq., M.P., the Master
and Wardens of the Worshipful Company of Gardeners, R. McLachlan,
Ksq., F.R.S., T. Dorrien-Smith, Esq., R. Milne-Redhead, Esq., Sidney
Courtauld, Esq., and Mrs. Courtauld, T. B. Heywood, Esq., Dr. Fripp,
N. N. Sherwood, Ksq., and Miss Sherwood, Frederick G. Lloyd, Esq., and
Mrs. Lloyd, J. Wigan, Esq., Charles EK. Shea, Esq., Harry J. Veitch,
sq., the Rev. P. Edwards, M.A., the Rev. Geo. H. Kngleheart, M.A.,
i. Gofton Salmond, Esq., and others.
THE BANQUET. 41
The chair was taken by Sir Trevor Lawrence, Bart., President of the
Society, who was accompanied by Lady Lawrence.
Dinner being ended, the following toasts were proposed :—
1. “ Her Most Gracious Majesty the Queen and Empress.”
(Patron of the Society.)
Proposed by the Chairman, Sir Trevor Lawrence, Bart.
2. “ Horticulture.”
Proposed by the Rev. Professor George Henslow, M.A., V.M.H., &ce.
Responded to by Herbert J. Webber, Esq., Special Envoy from the United States
Department of Agriculture.
Professer Hugo de Vries, Amsterdam University.
Monsieur Henry de Vilmorin, Horticultural Society of France.
3. “ Hybridists.”
Proposed by W. Bateson, Esq., F.R.S., Cambridge University.
Responded to by Monsieur de la Devansaye.
Walter T. Swingle, Esqy., Washington, U.S.A.
4. “ The Royal Horticultural Society.”
Proposed by the Master of the Rolls (Lord Justice Lindley).
Responded to by the President of the Society (Sir Trevor Lawrence, Bart.)
5. “ The Visitors.”
Proposed by Charles E. Shea, Esq., Member of Council.
Responded to by His Excellency the Belgian Minister.
6. “ The Chairman.”
Proposed by Monsieur Mark Micheli, Geneva, Switzerland.
Responded to by Sir Trevor Lawrence, Bart. (President of the Society.)
In proposing the first toast, the President, Sir TRevor LAWRENCE,
said :—Your Excellencies, my Lords, Ladies, and Gentlemen,—The toast
that I have to propose to you is “The health of Her Most Gracious Majesty
the Queen, Empress of India, the Prince and Princess of Wales, and the
Rest of the Royal Family.” It is not necessary for me to say a single
word about Her Majesty the Queen. During the many years that she has
reigned over us we have becom? more devoted to her year by year. Her
Majesty the Queen is the patron of our Society, and in years past Her
Majesty’s illustrious consort was President of the Society, and did all he
possibly could to promote its welfare. With regard to Their Royal
Highnegses the Prince and Princess of Wales, without claiming for them
that they are special devotees of the art and science of horticulture, I
have had the honour of escorting His Royal Highness and Her Royal
Highness and the Duke and Duchess of York round the exhibitions of the
Society at the Inner Temple and elsewhere on more than one occasion,
and they have always expressed themselves highly delighted, as indeed
they may well have been, with what they saw. I propose to you ‘‘ The
health of Her Gracious Majesty the Queen, Their Royal Highnesses the
Prince and Princess of Wales, and the Rest of the Royal Family.”
In proposing the second toast, the Rev. Professor HENsLow said :—
Your Excellencies, my Lords, Ladies, and Gentlemen,—No one can regret
more than myself that I am speaking to you at the present moment.
We hoped to hear Sir Michael Foster, Secretary of the Royal
Society, on this occasion; but at the last. moment, I regret to
say, he is laid on a bed of sickness and cannot be with us
to-night. Having been asked by Sir Trevor Lawrence, at a moment's
notice, to take his place, you can imagine that it was with no
42, JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
great feelings of pleasure that I undertook the responsibility. I thought,
“What can I say about horticulture?’ If I deal with it in its
modern aspects I shall not know where to begin, what to say, or how to
end. J thought, if I speak on the horticulture of past days, there is little
or nothing left to be said. If we ask, what did the ancients know about
horticulture—had they any ideas about horticulture as we have ? we find
a great gap, an absolute silence. All we can find about their gardens is
that they were “herb” gardens. We have all heard of a certain king
who robbed a man of his estate and turned it into a garden of herbs.
We have all heard about the paradise of the Greeks, that consisted of
trees, walks, and so forth. But when we turn to see what they did in
the cultivation of flowers, it is extraordinary that history is perfectly
silent. The great writersof the early centuries of this era, or a little
before it, scarcely spoke of gardens at all. I think probably twenty-five
varieties of plants would cover everything in their gardens; but then in
their regions wild flowers were so abundant and beautiful that there
was no necessity to grow flowers in their gardens. I remember Seneca,
in denouncing the luxurious habits of the Roman nobles of his
time, speaks of the extravagance of making dishes of larks’
tongues, and adds that they literally stripped the fields of their
flowers to adorn their feasts. Ovid speaks of a Rose garden,
but I doubt whether this was more than a few wild Roses. When
we come to the dark ages of the fifteenth century—(we hear of
nothing before, except a few Lettuces and such things, though, that
reminds me, the Romans were proud of their gardens, and some of the
great families named themselves after Beans and Lettuces)—coming down
to the middle ages, there is nothing tobe said. In the sixteenth century,
flowers at last began to be cultivated. But if we look at our own
country, we do not find much in the way of flowers until the eighteenth
century, and it isin the nineteenth century we get them coming in witha
rush. The Chrysanthemums came dribbling in between the tens, twenties,
and thirties of this century, and with a great rush in 1842. The
Calceolarias also came in during this time. And then a few gardeners
began to cross plants, which is the subject which brings us here to-night.
The idea of crossing hitherto was unknown. The ancients were quite
aware of it so far as the Palm was concerned. I mean the Date Palm; and
we suppose that they artificially fertilised the Fig; but they knew nothing
about the sexes of plants; they knew that if an enemy was in the country
the first thing to be done was to cut down the male trees, so as to ruin the
crop of Dates without having to destroy the Date-bearing trees. It is
attributed to Sir Thomas Midleton that he first suggested that the pollen
and stigma should be united to make seed. Linneus took it up as you
know ; but it was not until Knight, the President of the Royal Horti-
cultural Society, and Dean Herbert took up the subject of crossing that
we entered on an entirely new field that transcends to-day everything
else in the realm of horticulture. I have travelled as quickly as I could
over that vast subject of. ‘ Horticulture’? which has been entrusted to
me, and I will only ask you to drink continued success to it, coupled with
the names of those eminent exponents of it—Mr. Herbert J. Webber, of
the Department of Agriculture and Horticulture-of the United States of
THE BANQUET. 43:
America; Professor Hugo de Vries, of the University of Amsterdam ; and
Monsieur Henry de Vilmorin, Vice-President of the Société Nationale
d’ Horticulture de France.
Mr. Hersert J. Wesser :—Sir Trevor Lawrence, your Excellencies,
my Lords, Ladies, and Gentlemen,—It gives me the greatest pleasure to
have this honour of addressing you this evening, and I have furthermore
pleasure in bringing to you across the seas the greeting—the most
friendly greeting—of the Secretary of Agriculture of America, who has
the greatest hopes for the future of horticulture and in the final develop-
ment and advancement of all its allied industries, not only in America
and the United States, but in the entire world. He looks upon our
present condition as simply a formative one, and likely to lead to more
important advancement and results, and in this I think the experience of
this Conference bears our Secretary out. It seems to me, from what has
been brought out at our meetings, that we are on the eve of a great
advancement, and what has been done is simply a herald of the advance
that is to come in the future. It is, however, a great misfortune, as was
so forcibly brought out in our meeting this afternoon, that there is no
way by which the originator of a new fruit or flower can reap the equiva-
lent benefit. There is no doubt a certain amount of honour and pleasure
and personal satisfaction in having originated something of this kind ;
but, after all, that is not quite sufficient reward. There should be more
just and satisfactory recompense at the same time. How this can be
brought about, gentlemen, is, of course, matter for consideration, but it
lies with us to largely compensate the man—the originator of a new fruit
or flower—to give him his just dues. It seems to me that the man
who in any way lightens the struggle of humanity, or puts bread into the
mouths of the starving, by improving our crops or giving us better yields,
more appetising fruits or more delightsome flowers, is worthy of more
honour than the man who invents a new pill, or a new kind of soap, or
who writes a new novel, or than the man who makes war. After all,
we should be at peace. We scientific men are at peace with one another.
Science is an international thing. What we have to do is to popularise
our work so that any development may meet with its just reward; and
it seems to me I can look forward into the very near future and see the
time rapidly approaching when a new discovery in horticulture in this
land will meet its just recompense of reward.
Professor Huco pE Vrirs :—Mr. Chairman, your Excellencies, my
Lord, Ladies, and Gentlemen,—One of the ideas of this Conference that has
struck me most has been the desire to bring together men of science
and of horticultural practice to exchange views. Almost all the papers
showed clearly this tendency. Formerly there was very little feeling of
community or of continuity between practice and science, but now on both
sides this estrangement is being diminished, and the same sort of bonds
that have brought engineering and electricity and all applied sciences
to act together, in order to allow such magnificent results, must be
brought into action in order to unite scientific and practical horti-
culturists in the realms of hybridisation. It seems that the objects we
aim at are not to be so soon reached as we all wish. But what I have
most enjoyed in this Conference is to see that feeling of fellowship
44 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
stretched far wider than I have ever known it before. The interest of your
experiments are so wide that even zoologists have been brought to this
Conference, and even they by attending to the work of the hybridist may
gain some new light. The first paper we listened to yesterday was by
Mr. Bateson, whose views, I believe, were founded on discontinuity in
nature. Discontinuity is here the basis of continuity, for this
gathering of different nations and sciences must needs lead to a greater
union.
M. Henry pe Vinmorin :—My Lords, your Excellencies, Ladies, and
Gentlemen,—I feel it a duty to thank the Royal Horticultural Society of
Great Britain for the compliment paid to myself and my country in being
invited to this meeting—most opportunely called together by the Royal
Horticultural Society. Too much cannot be said about the importance
and the value of horticulture as a part of the national wealth of any
country. Horticulture has been said to be, and is certainly, the highest
and most perfect form of agriculture. It is the science that brings out
the highest results from the soil, and that constitutes most of the wealth
of any and every nation. But horticulture, like every economical under-
taking, is at the present time working under difficulties. New competition
and new difficulties are creeping up every year; and now when this
century is waning and another is coming we have to be considering
harder than ever how best to improve the condition of horticulture in
every country in this world. ‘The difficulties of horticulture, for example,
are increasing in relation to the increased price of coals. We see in
many parts of the world, and in this part in particular, that coals
are used very largely for promoting the quick growth of plants, especially
of fruit. But at the same time you see that the progress of navigation is
so rapid that it is becoming an awkward problem in many cases whether
it is more profitable to use coals to heat steamers to steam ten or
fifteen miles an hour to bring fruit from distant countries, or to use the
coal to bring forth earlier crops in our own countries at home. But if we
could so alter the varieties of fruits that we could raise them by heat in a
few weeks, then we should know what to do. Itis to our hybridists,
then, that we must look to make our old varieties earlier and able to be
brought to maturity in a short time. Our efforts must be made to bring
this about. Plants are our tools. They are the organs by which we
obtain all precious results in horticulture. By improving our tools we
are doing what all sorts of industry are trying to obtain—an improvement
of their finished productions.
In proposing the third toast, that of ‘‘ Hybridists,’”’ Mr. W. Barrson,
F.R.S., said :—Mr. Chairman, your Excellencies, my Lords, Ladies, and
Gentlemen,—I hardly knew to what I owed the honour of being chosen to
propose this toast of ‘‘ Hybridists’”’ to-night until I recollected that
perhaps I was the only man in the room who could say he had never
produced a single hybrid. For this toast is practically the toast of our-
selves. ‘There must be very few here present who are not included in
the term ‘‘ hybridists.”’ I think it is not difficult to anticipate that this
toast will be drunk with alacrity. What is a hybridist ? If you turn up
the dictionary you find it is connected with the Greek word tprc, which
means ‘‘ lawless.” But in these two days that it has been my great
THE BANQUET. 45
privilege to associate with hybridists from many parts of the world, I
have come to believe there is no more law-abiding body to be found than
the hybridists assembled here to-night. Their business is to find out
what the law which governs hybridism and kindred phenomena is, and
they are determined to do it. It is with the law that governs natural
things as it is with the law of the land, you never know what it is until
you get at the point of breaking it, if I may say so in the presence of
one of Her Majesty’s most eminent Judges. You must go on until you
break the law, and then, at last, you know its limitations. The man
who invented the metric system and incubators—the Chinese invented
incubators, of course; but I mean the man who invented incu-
bators we could use—in his interesting book, said one of the projects
he set himself to carry out was to hybridise a rabbit and a fowl. But
there, as Professor Henslow would say, his experiments in hybridisation
failed. He found he had reached the confines of law. But without
going so far as that there are many, many laws which we are perfectly
certain we can find out, and which, if found out, would produce a most
effective development in science and practice. It is the motto of our
sister society, the Royal Agricultural Society, “Science with practice ”’ ;
and a great deal has been said of the possibilities before us if we adopt
this motto too. I believe the Agricultural society, in saying ‘science
with practice,’ meant to imply that practice is to gain by its asso-
ciation with science. I am afraid that in hybridising all the gain is
going to be on the side of science. If we could fully ally science
with practice in horticulture, it seems to me that the gain would be
all to science, for on the subject of hybridisation scientific people
have little or nothing to tell us as yet. There was once a society that
existed for the purpose of mending the clothes of the poor—darning
and sewing on buttons, and so forth. Once an Irishman, of whom you
may have heard, came to that society with a button in his hand and said,
“Tf you would be so good as to sew a shirt to this button, I should be
very much obliged.” That is like science and practice in horticultural
hybridisation. Science produces the button and practice has to bring
the shirt. But by-and-by that will be all adjusted. Everybody knows
how things began with electricity, chemistry, and so forth, and so it will
be in horticulture and hybridisation. When I think of those who are to
respond to this toast, Mr. Swingle, who is associated with that extra-
ordinary development the Bureau of Agriculture in America, which has
experiment stations all over that vast continent; when I think of the
opportunities which they have which we in England have not, for in
England, apart from private enterprise, there is nothing of the sort going
on; when we think of all this, of the time that must elapse before equip-
ment for scientific research can be set up, and any valuable results be
gained, it is essential that some permanent record be made. As one sees
sometimes in legal documents, “ Time is of the essence of the contract.’’
Without having the guarantee that these experiments will be carried
on beyond our lifetime, many people think it is not worth while to begin
them. We need a permanent home, so that the work that has been
done will not be swept away into oblivion when we ourselves happen
to go. Surely sooner or later someone will come forward and offer
46 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
this grand old Society such an establishment. I believe there is
nothing that is so likely to revolutionise the scientific knowledge of
animals and plants as such an establishment as I am _ speaking of
would; and I think the best result of such a Conference as this is to
stir up people’s minds and make them think seriously of my sugges-
tion. It is perfectly certain that there are great successes to be reached
in these fields. I feel certain our experiments will not prove sterile, but
will produce flowers and fruit which will be awarded by posterity with an
“BR.C.C.” This means—I explain for the benefit of the uninitiated—that
the fruit of this Congress will be hereafter judged and awarded a first-
class certificate.
Monsieur DE LA DrvANSAYE (who spoke in French) :—Sir Trevor
Lawrence, your Excellencies, my Lords, Ladies, and Gentlemen,—It gives
me the greatest delight to respond to this toast. Hybridisation has been
one of the great pleasures of my life. I see in it the potentiality of quite
an amazing extension of the world of plants, and that not in the very far
distant future as world periods are reckoned. There appears to me to be
practically no limit to what the hybridist may accomplish. Of course I
mean no limit within that boundary of natural laws which Mr. Bateson
has so humorously referred to. Gentlemen, I wish I could address you
in your own language, but it is too hard for me. Ithank you for inviting
me to this most interesting Conference, and I hope it may be continued
and reopened at our great Exhibition next year in Paris, when we shall
be only too proud to give you as hearty a welcome in my country as we
foreign guests have so heartily appreciated and enjoyed in yours.
Mr. Water T. Swiyeue, Department of Scientific Agriculture,
Washington, U.S.A. :—It is with particular pleasure that I, a cousin
from across the sea, rise on this occasion to respond to the toast of
“ Hybridists.”” It seems particularly appropriate that the Conference
should be held in England, for it is in this island that Thomas Fairchild
made the first hybrid known to the learned world. I don’t think it was
the first hybrid that existed, but it was the first hybrid known. It is
also with particular pleasure that it is under the auspices of the Royal
Horticultural Society, which has published the magnificent work of Dean
Herbert, that I respond to this toast. It seems to me it is scarcely
possible for us to over-estimate the future of the hybridist. When we
recollect that scarce two hundred years ago Thomas Fairchild made the
first hybrid ever known, and that now there have come people from all
parts of the world deeply interested in the subject, and when we think of
what a tremendous future there is for the improvement of our flowers,
our fruits and foodstuffs, and all that appeals to our pleasure and our
sense of beauty, we realise that hybridisation is the best and noblest
branch of horticulture.
In proposing the toast of “The Royal Horticultural Society,’ Lord
Justice LinpuEy, Master of the Rolls, said:—Mr. President, your Kx-
cellencies, my Lords, Ladies, and Gentlemen,—It will probably be a
matter of some speculation and perhaps surprise that an old lawyer like
myself should be invited to propose to you the toast of the Royal
Horticultural Society. The reason is known to a few, and I will state it
to those who are unaware of it. Iam the bearer of a name which-I am
THE BANQUET. AT
proud to say was borne by a man who in his day for thirty-five years was
the life and soul of the Royal Horticultural Society. I am not old
enough to recollect the creation of the Society, for it was started in 1804 ;
but I am old enough to recollect those days which were the glorious,
prosperous days of the Society—the days of the great Chiswick fétes in
May, June, and July, when all the rank and fashion of London and the
country went down to enjoy those great fétes. They developed in my
own time from that iron skeleton of a tent which used to stand in the
arboretum of the Society till they culminated in those wonderful shows at
Chiswick, and later on at Kensington. These were days when the Horticul-
tural Society’s exertions took the form of sending out explorers and col-
lectors all over the globe, and the work they did was astonishing to those
who are aware of their results. Irecollectsome of them. There was that
fiery Douglas, who went out to Oregon and the Far West and met his
death by being gored by a buffalo, as I recollect. Then I recollect
Robert Fortune, a Scotchman, who, thanks to his high cheek-bones, his
knowledge of Chinese, and his extraordinary dexterity with chopsticks,
held his own in those outlandish Chinese places where he risked his life in
order to obtain information. Those are the days that are past. Those
are the days when money came in from the wealthy and from those
who visited the Society. I recollect the time when the Emperor Nicholas
was at Chiswick. There were more than 14,000 people present ;
and then came a time of depression. The Horticultural Society had
certainly given an enormous spur to the life of gardening. But times
were not prosperous. Chiswick Gardens were curtailed, and the
arboretum had to be given up. Then we came to South Kensington,
and there came again a time of outward prosperity, followed by a terrible
blight. These tactics were changed. You appealed to scientific men
rather than to the wealthy. You pursued a new course of utility. You
adopted a distinctly horticultural policy with a lower rate of subscriptions,
and, thanks to these things, but, above all, to the energy of your Presi-
dent, Sir Trevor Lawrence, and your hard-working and genial Secretary,
Mr. Wilks, the Society now is entering upon a career which I trust will
be as prosperous, if not more so than in the past. I have heard some-
thing about hybridisation, of which I know little. I have heard
something which leads me to suppose that the development of that art
may react upon the profession to which I have the honour to belong.
Without being a prophet, I seem to see before me a vista of patent hybrids !
What a treat for the patent lawyers! and what an accession of work for
Her Majesty’s Judges! I invite you to drink to the health of the Royal
Horticultural Society as heartily as I have had the honour to propose it.
The Chairman (Sir TREvor Lawrence) :—The Master of the Rolls,
your Excellencies, my Lords, Ladies, and Gentlemen,—I must confess it
was with peculiar satisfaction that I received an intimation from the
Master of the Rolls that he would give us the honour of his company
here to-night. It is quite impossible for anyone who remembers the
invaluable services which were rendered by his father to the Royal
Horticultural Society and to the cause of the science of botany to do
other than rejoice that a man who, like the Master of the Rolls, has
made his mark in the world, though in a different direction from that of
48 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
his father, should be present here as our guest to-night. The Master of
the Rolls has referred to some of the early parts of the history of this
Society. The Society, as he has justly and correctly said, was founded
in 1804, and our excellent and most energetic Secretary is already asking
us how we are going to celebrate our centenary. There are numerous
suggestions, and I am not going to trouble you with them to-night; but
I think I may fairly claim for the Royal Horticultural Society that
during the nearly hundred years that it has existed it has done very
valuable work, not only in the cause of horticulture, but for the advance-
ment of that which has giyen incalculable pleasure and delight to
the people of this country. I very much wonder whether that very
distinguished botanist, Sir Joseph Banks, in co-operation with Mr.
Andrew Knight, whose name is so well known to hybridists, quite
foresaw the yery valuable work they were setting on foot when they
met together at 187 Piccadilly, then occupied by Messrs. Hatchard,
the booksellers, to inaugurate this Society. The objects of the Society
were these, to foster and encourage every branch of horticulture and all
arts and sciences connected with it. And when a few years later the
Society had a Charter, a Royal Charter, granted to it, the objects were
set forth very briefly—the improvement of horticulture in all its
branches, ornamental as well as useful. As the Master of the Rolls
has already told you, the Society in those early days sent out many
collectors—not only those whom he has mentioned, but many others
besides. I venture to think that when the Royal Horticultural
Society sent Robert Fortune to China it was hardly aware that
it was laying the foundation for the revolution of a great trade, for trans-
ferring to one country a great trade which up to that time had been
the property of another country. I mean the shifting of the tea trade to
a great extent from China to India. For it was owing to the fact that
Robert Fortune was sent out by this Society to China that the cultivation
of tea was undertaken in the Himalayas. It spread thence to Ceylon, and
so, as we know, at the present time the great bulk of the tea which is
consumed in Western countries comes, not from China, but from those
countries into which Robert Fortune introduced it. With regard to the
Scotchman who could not get out of the way of the bullock, he was gored
to death in the Sandwich Islands, I believe. But with regard to Douglas he
has introduced so many valuable plants that it is justly remarked his efforts
and those of his colleagues have had marvellous results—results which
have affected all parts of England. ‘ For nowhere can a day’s ride now
be taken where the landscape is not beautified by some of the introduc-
tions of the Royal Horticultural Society.’’ That is a quotation from a
quarto volume which has some value, though not as much as it ought to
have, by Mr. Andrew Murray, who wrote an account of the Royal
Horticultural Society. The Master of the Rolls has referred to the
Chiswick Shows. I have always been of opinion, and every day I live my
opinion is strengthened, that when any society depends upon the some-
what fickle favours of fashion sooner or later it is certain to come
to grief. So far as the fashionable world was coneerned, as the
Master of the Rolls has observed, it used at one time to favour
Chiswick. Then something else attracted its attention, and at
THE BANQUET. 49
the same time the elements were most unpropitious, and the
Chiswick Shows came to an end. If the Royal Horticultural Society
during recent years has had the advantage of greater prosperity,
it has not been due, allow me to say, as I have been President for several
years—it has not been due to the exertions either of the President or
Council. It has been due to the fact that the President and Council of
late years have adopted the only true policy, which is—to stick to
horticulture. As long as any society, for which there is really any
public demand—as long as it sticks to the subject which it is created to
develop, so long will that society succeed. Our success, then, has been due,
not to individuals, but to the policy inaugurated some twelve years ago,
viz. that the Royal Horticultural Society existed, and should be con-
sidered to exist, wholly and solely for the promotion of scientific and
practical horticulture. There is one thing with regard to the Congress
we have been lately holding which I think has hardly perhaps been suf-
ficiently recognised—that is the enormous obligation which the public owe
to the hybridist and the horticulturist. There is scarcely a flower which
grows in our gardens which has not been created, or which has not been
enormously improved, by the work of hybridisation and selection. There
is scarcely a fruit on our tables which we do not owe to the successes of
the hybridist. Do you want early Strawberries? You get them. Do
you want late Strawberries? Yougetthem. All the result of hybridisa-
tion! If you want early or late Peaches you get them, the result of
hybridisation. With Grapes it is the same ; and so it is with vegetables,
Peas, French Beans, Cauliflowers, Broccoli, Lettuces, you get them early
and late—all the result of skilful hybridisation or of careful selection. I
venture to think the public at large owe a great debt of gratitude to the
horticultural profession for the enormous amount of work done in that
direction. Well now, I do not wish to detain you any longer; but there
is one thing I want to say before sitting down. The Royal Horticultural
Society has no doubt been progressing of late years by leaps and bounds.
We are now not far short of five thousand Fellows, a number which has
never been approached in former times, but a number which, so far as
I can see, will be by no means the limit of the popularity of the Society.
We are not wealthy, but we are at all events in fair water. But we want
two things. The Royal Horticultural Society wants a hall in London. If I
had the good fortune to be addressing an audience not of my fellow-Lon-
doners, but of the people of Manchester, or Liverpool, or one of our great
northern cities, I believe in all probability some one would get up and say,
“Twill build you that hall.”’ Now, is it impossible in this enormously rich
metropolis that some gentleman who has had the greatest possible plea-
sure and delight from horticulture will come forward with some few
thousands of his many millions and build us that hall? I cannot but
believe that such a man will shortly appear. We want another thing—a
new garden. Chiswick is too small,and too near London smoke. We
want a garden which will be called, I hope, the New Chiswick ; we cannot
abandon the old name. We want a new garden, and for that we want
money. I am thankful to say that the only card that has gone round
the tables to-night is on behalf of the photographer. We are not going
to send round the card to invite ladies and gentlemen to subscribe on
19
50 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
this occasion ; but if any lady—and I appeal more particularly to the
ladies, for they are great admirers of flowers, and have a great influence
on the opposite sex—if any lady present happens to have influence with
any millionaire, I ask her to be good enough to urge the claims of the
Royal Horticultural Society for a hall in London, and whether she
succeeds or not, the Society will be deeply indebted to her. I wish, in
conclusion, to say once more how grateful we are to our foreign friends
who are gathered round us in such numbers to-day. I beg to thank the
guests who have been good enough to be here to-night. This will be a
red-letter day in the history of the Society, and I hope on some future
occasion to have the great pleasure of seeing you all here again.
In proposing the toast of ‘‘The Visitors’? Mr. CHartes EK. SHEA
said :—I believe somewhere there is a telegram telling me I should have
to propose the toast that Sir John Llewelyn had undertaken to propose.
I had not the advantage enjoyed by Professor Henslow of receiving that
telegram before I started, but on arriving I received the digestion-
destroying command of the Secretary to take the place of Sir John. Of
course the Secretary has made an enemy of me for life. But at the
same time I felt that the toast was one that should be so easy, so pleasant,
to propose that I accepted it. The occasion is graced to-night by the
presence of many ladies, not only from England, but from abroad. Sir
Trevor Lawrence has just laid a rather heavy charge on the ladies to
build us a hall. Now they know what they have to do. Sir Trevor
Lawrence has in his mind what we are all thinking—‘“ the hand that
rocks the cradle rules the world,’’ and we of the Royal Horticultural
Society would be the first to submit to and to admit the sweet sway which
they have over us all. I do not think that we horticulturists altogether
appreciate the great good which ladies have done for horticulture. We
have to-night many distinguished visitors. We have the Ministers—the
Belgian Minister, who is the representative of a country famed all the
world over for its love of and its skill in horticulture. Then we have the
Netherlands Minister, a keen friend of horticulture, who, in the Nether-
lands, holds the same position as Sir Trevor Lawrence does here. Time
necessitates my passing by our English friends—Mr. Bateson, whose
name we all know; Sir Michael Foster, whose absence, through
illness, we all so much regret. But I will pass to the foreigners.
We have among us no less than four representatives of our cousins
across the water. We receive them to-night not only in their
individual capacity, but as sent by the Government of the United
States of America as a token of friendship and appreciation. We have
Mr. Webber, Mr. Hays, Mr. Fairchild, and Mr. Swingle. France sends
us many guests to-night—Monsieur de la Devansaye, the two Messieurs
de Vilmorin, and others. Germany sends us again our friend Herr
Schmidt, and we have from Holland our distinguished guest Professor
Hugo de Vries and Herr Simon de Graaf. There are many others here
that lack of time alone prevents me from mentioning. But let me deal
for one moment with the impressions that the Conference has left on my
mind. I think the impression our visitors will take back with them, as I
shall take away with me, is the immense practical use of the Congress
we have held. Our visitors, I think, will take back certain lessons.
THE BANQUET. 51
They cannot help doing so. They, on their part, have taught us many
lessons. I refer more to the American, because the Continental methods
are so much more allied to our own that it is difficult to differentiate
between ours and theirs. Perhaps we, of Europe, are too speculative
and less practical than we ought to be. I admire scientific speculation
tending towards the elucidation of first causes; but I was deeply im-
pressed by the fierce, practical, utilitarian methods of the Americans,
as Mr. Webber laid them before us this afternoon in a very
strong and practical manner. Our American cousins know what they
want, and they go straight at it. They get a “freeze’’ among the
Oranges, and they say at once, “‘ We must get Oranges that will withstand
a frost,” and they go straight at it. They try other Oranges and make a
multitude of experiments towards the desired goal. Another point that
has struck me very much, a point accentuated by Mr. Webber's lecture,
was this—the large support which is given to the important matters of
horticulture and agriculture by the Government of the United States.
In our own country, if we went to the Chancellor of the Exchequer to ask
for an extra hundred or so for Kew, we should be met by the usual
official and departmental frown. Mr. Webber has told us that horti-
culture brings us all together, arouses in us those sympathies, those
friendly feelings, which have been exhibited so largely the last few days.
At the Hague there has been a conference with the object of making
nations settle their disputes without going to war. It seems not to have
suggested itself to the representatives of the Great Powers that there
is one way which would render ironclads and Maxim guns drugs on the
market—that all these nations should become Fellows of the Royal
Horticultural Society.
His Excentency THE Bexta@ian Minister :—Mr. Chairman, my
Lords, Ladies, and Gentlemen,—To. be called upon to respond to the
toast which you have just honoured is always regarded by every member
of the body to which I belong not only as a matter of international
courtesy, but as a very great personal pleasure. The exceedingly kind
manner in which it was proposed and acknowledged encourages me to
ask a yet further favour at your hands—that you will not take any poor
words of mine as expressing my full sense of your kindness, and of the
honour you have done to the visitors. This is no ordinary occasion. It
is one which every one of us here will long remember for reasons
which are common to us all. But each of us, no doubt, will have some
special reason for its recollection. Speaking for myself, it will hold a
leading place among my memories of all the kindness, all the hospitality,
all the friendship that I have enjoyed since I first found myself at home
among Englishmen. I say “at home”’ advisedly, for I know how much
that word means here, and all that it meansin England. It is, further-
more, our common diplomatic experience that British hospitality, not only
in the special sense in which we enjoy it here this evening, but in the
friendly offices of every day, is unsurpassed throughout-the world. But,
if this be true of the official representatives of all countries, how much
more true must it be for the countries which are so specially and
honourably represented here this evening. Speaking specially for the
country and the Sovereign I have the honour to serve, | need not remind
22
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52 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
you of the cordial friendship and admiration of that country for your
own. You are aware also how deeply interested my august Sovereign is
in all that concerns horticulture, to which he is very sincerely devoted,
asit is also one of our national tastes. Gentlemen, I can now only ask you
to accept our warmest thanks for this evening’s welcome, and for the
great honour you have conferred upon us by giving that welcome such
cordial expression, and I fervently wish that our thanks could be as
eloquent as they are sincere.
Monsieur Mark Micweui, of Geneva, Switzerland, in proposing the
health of the Chairman, said:—Mr. Chairman, your Excellencies, and
Gentlemen,—Allow me a very few words. At one time there was a little
disagreement between botany and horticulture. Some botanists look
down a little on horticulture; some look down a little on the horticul-
tural varieties of plants. But what would be our garden—what would
be the worth of the flower without the work of horticulture, and the
work of the hybridist ? We have many instances of it around us. These
flowers that cover the table here are due to the horticultural art. It is
due to the efforts of horticulturists that we have all these beautiful Water-
lilies that are gracing our table, and now from a practical point of view
the botanist can only look on the hybridist and horticulturist with very
sreat satisfaction. From a practical point of view, hybridisation and
horticulture are very useful to botany; but besides that from a scientific
point of view, we have heard to-day at the meetings that the question of
hybridisation might be treated from a scientific point of view, and we
have had some papers which were of a scientific nature. One of the
best ways to obtain our ends is by well-organised societies which will
facilitate the work and help the workers on in their enterprise. I think
not many societies are so well blessed as your Royal Horticultural
Society, which is so ably directed by your most admirable President,
Sir Trevor Lawrence, our Chairman to-night, to whom I am most happy
to raise my glass, and invite you all to do likewise.
The toast was drunk with ‘ three times three.”’
The CHarrman :—M. Micheli, your Excellencies, my Lords, Ladies,
and Gentlemen,—I am extremely obliged for the very kind way in which
you have referred to the Society and to myself. I think I may venture
to say on behalf of the Society that we greatly admire the fluency and
the admirable way in which our foreign guests have spoken to us in
English to-night. I am afraid when we have the honour of visiting
Ghent, or Geneva, or Amsterdam, or wherever it may be, that we shall
be unreasonable enough to expect the inhabitants of those countries to
listen to our English speech. That reminds me. I have ason just going
into the Army, and concerning him I had the honour of asking Lord
Wolseley’s advice. He said: ‘‘ There are two things your son ought to
be able to do—to ride very well and to speak foreign languages.” I am
afraid the latter art is not cultivated so much as it ought to be in this
country. I ami sure of one thing—that we are very grateful to our
foreign guests for the very successful efforts they have made in expressing
what they desired to say in our somewhat stubborn and difficult tongue.
I can only repeat what I have said before, that we have been very pleased
indeed to see the cordiality with which our foreign guests have come
LUNCHEON AT CROYDON. D3
round us. We appreciate their presence exceedingly. We know what
valuable work they are doing in the cause of horticulture. We know
what they have said about the Society has been said from their hearts,
and we thank them most heartily for what they have said.
* * * * *
The proceedings of the Conference were brought to a close by a most
enjoyable Luncheon and Garden Party on Thursday, July 13, given by
the Master of the Worshipful Company of Gardeners, Philip Crowley,
Esq., F.L.S., F.Z.8., &e., &e., at his residence, Waddon House, near
Croydon. Covers were laid for 120, and among the guests invited were
the Right Hon. C. T. Ritchie, M.P., and Mrs. Ritchie, Sir Trevor
Lawrence, Bart., and Lady Lawrence, Sir John Llewelyn, Bart., M.P.,
and Lady Llewelyn, Sir Frederick and Lady Edridge, Sir William and
Lady Farmer, Colonel and Sheriff Probyn and Mrs. Probyn, the Mayor
and Mayoress of Croydon, the Master of the Leathersellers’ Company,
the Rev. Canon and Mrs. Pereira, and all the foreign and distinguished
members of the Conference.
Special trains conveyed the guests from London, setting them down
at the very boundary of Mr. Crowley’s gardens. Luncheon was served
in a marquee, a military band being in attendance. After luncheon, Mr.
Crowley received upwards of 250 guests at a Garden Party, and when
the time came for the special train to convey the members of the Con-
ference back to London all were agreed that a most delightful conclusion
had been given to the Conference by the hearty welcome and unbounded
hospitality of the Master of the Gardeners’ Company.
54 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Fic. 8.—Nepenrues mixta. (Journal of Horticulture.)
(N. Currist x N. NorrHiana.)
CONFERENCE. 55
CONFERENCE.
TuEsDAY, JuLY 11, 1899, ar CHISWICK. .
Introductory Address by Dr. Maxwetu T. Masters, F.R.S., Officer of
the Order of Leopold, &c., &e.
Our first duty, and a very pleasant one it is, is to welcome our foreign
cuests, our friends from across the sea as I prefer to call them, to thank
them for their presence here to-day, and to express a hope that their
sojourn among us may be both agreeable and profitable. At the same
time we regret that some such as Dr. Focke, the historian of hybridi-
sation, has not been able to preside over this meeting, as we had hoped
he might have done. Nor can we at such a meeting do other than express
our abiding regret at the loss, though at an advanced age, of the great
hybridiser, Charles Naudin.
Our next duty is to thank the Council of the Royal Horticultural
Society for this opportunity of meeting once more in these time-honoured
gardens to discuss what, I venture to think, is one of the, if not the most
important subject in modern progressive experimental horticulture. I
use the words progressive and experimental because I believe that the
future of horticulture depends very greatly on well-directed experiment.
So far as the details of practical cultivation are concerned we are not
so much in advance of our forefathers. We have infinitely greater
advantages, and we have made use of them, but if they had had them
they would have done the same. We are able to bring to bear on our .
art not only the ‘‘ resources of civilisation ’’ to a degree impossible to our
predecessors, but we can avail ourselves also of the teachings of science,
and endeavour to apply them for the benefit of practical gardening. We
are mere infants in this matter at present, and we can only dimly per-
ceive the enormous strides that gardening will make when more fully
guided and directed by scientific investigations. One object of this Con-
ference is to show that cultural excellence by itself will not secure
progress, and to forward this progress by discussing the subject of cross-
breeding and hybridisation in all their degrees, alike in their practical
and in their scientific aspects.
To appreciate the importance of cross-breeding and hybridisation we
we have only to look round our gardens and our exhibition-tents, or to
scan the catalogues of our nurserymen. Selection has done and is doing
much for the improvement of our plants, but it is cross-breeding which
has furnished us with the materials for selection.
A few years ago by the expression “new plants,’’ we meant plants
newly introduced from other countries, but, with the possible exception
of Orchids, the number of new plants of this description is now relatively
few.
The “new plants ’’ of the present day, like the Roses, the Chrysan-
themums, the Fuchsias, and so many others, are the products of the
gardener’s skill. From Peaches to Potatos, from Peas to Plums, from
56 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Strawberries to Savoys, the work of the cross-breeder is seen improving
the quality and the quantity of our products, adapting them to different
climates and conditions, hastening their production in spring, prolonging
their duration inautumn.* Surely inthese matters we have outdistanced
our ancestors.
But let us not forget that they showed us the way. Ido not propose
to dilate on the share which Camerarius, Millington, Grew, Morland, and
others at the close of the seventeenth century had in definitely establish-
ing the fact of sexuality in plants; but I do wish to emphasise the fact
that it was by experiment, not by speculation, nor even by observation,
that the fact was proved; and I do wish to show that our English
gardeners and experimenters were even at that time quite aware of the
importance of their discovery, and forestalled our Herbert and Darwin in
the inferences they drew from it. In proof of which allow me to quote
from a work of Richard Bradley, called ‘‘ New Improvements of Planting
and Gardening, both Philosophical and Practical,’ published in 1717,
cap. ii. After alluding to the discovery of the method of the fertilisation
of plants, he says (p. 22) :—
“ By this knowledge we may alter the property and taste of any fruit
by impregnating the one with the farina of another of the same class; as,
for example, a Codlin with a Pearmain, which will occasion the Codlin so
impregnated to last a longer time than usual, and be of a sharper taste ;
or if the winter fruits should be fecundated with the dust of the summer
kinds they will decay before their usual time; and it is from this acci-
dental coupling of the farina of one with the other that in an orchard
where there is variety of Apples even the fruits gathered from the same
tree differ in their flavour and times of ripening ; and, moreover, the seeds
of those Apples so generated, being changed by that means from their
natural qualities, will produce different kinds of fruit if they are sown.
“Tis from this accidental coupling that proceeds the numberiess
varieties of fruits and flowers which are raised every day from
seed
‘Moreover, a curious person may by this knowledge produce such
rare kinds of plants as have not yet been heard of by making choice of
two plants for his purpose, as are near alike in their parts, but chiefly in
their flowers or seed vessels; for example, the Carnation and Sweet
William are in some respects alike : the farina of the one will impregnate
the other, and the seed so enlivened will produce a plant differing from
either, as may now be seen in the garden of Mr. Thomas Fairchild, of
Hoxton, a plant neither Sweet William nor Carnation, but resembling
both equally, which was raised from the seed of a Carnation that had
been impregnated by the farina of the Sweet William.”’
Here we have the first record of an artificially produced hybrid, and
you will remark that this was more than forty years before Kolreuter
began his elaborate series of experiments. Fairchild was the friend and
associate of Philip Miller, and of a small knot of ‘‘advanced”’ thinkers,
* See some interesting observations of MacFarlane on the period of flowering in
hybrids as intermediate between that of the parents, Gardeners’ Chronicle, June 20,
1891; and on the structure of hybrids, May 3, 1890. :
OPENING ADDRESS, BY)
and workers who banded themselves together into a ‘‘ Society of
Gardeners.”’
“He is mentioned,” says Johnson in his “History of English
Gardening,” “ throughout Bradley’s works as a man of general informa-
tion and fond of scientific research, and in them are given many of his
experiments to demonstrate the sexuality of plants and their possession
of a circulatory system. He was a commercial gardener at Hoxton,
carrying on one of the largest trades as a nurseryman and florist that were
then established. He was one of the largest English cultivators of a
vineyard, of which he had one at Hoxton as late as 1722. He died in
1729, leaving funds for insuring the delivery of a sermon annually in the
Churel: of St. Leonard’s, Shoreditch, on Whit Tuesday, ‘ On the wonder-
ful works of Godin the Creation ; or, On the certainty of the resurrection
of the dead proved by the certain changes of the animal and vegetable
parts of the Creation.’ ”’
Fairchild was thus not only the raiser of the first garden hybrid, but
the originator of the flower services now popular in our churches.
We do not hear much of intentionally raised hybrids from this time
till that of Linneus, in 1759.* The great Swedish naturalist having
observed in his garden a Tragopogon, apparently a hybrid between T.
pratensis and T. parvifolius, set to work to ascertain by experiment
whether this conjecture was correct. He placed pollen of T. parvifolius
on to the stigmas of T. pratensis, obtained seed, and from this seed the
hybrid was produced.
About the same time (that is, in 1760) Kolreuter began his elaborate
experiments ; but these were made with no practical aim, and thus for a
time suffered unmerited oblivion.
Some years after the President of this Society, Thomas Andrew
Knight, and specially Dean Herbert, took up the work, with what
splendid results you all know.
It is curious, however, to note that objections and prejudices arose
from two sources. Many worthy people objected to the production of
hybrids on the ground that it was an impious interference with the laws
of Nature. To such an extent was this prejudice carried that a former
firm of nurserymen at Tooting, celebrated in their day for the culture,
amongst other things, of Heaths, in order to avoid wounding sensitive
susceptibilities, exhibited as new species introduced from the Cape of Good
Hope forms which had really been originated by cross-breeding in their
own nurseries.
The best answer to this prejudice was supplied by Dean Herbert, whose
orthodoxy was beyond suspicion. He, like Linnezeus before him, had
observed the existence of naturai hybrids, and he set to work to prove
experimentally the justness of his opinion. He succeeded in raising, as
Engleheart has done since, many hybrid Narcissi, such as he had seen
wild in the Pyrenees, by means of artificial cross-breeding. If such
forms exist in nature, there can be no impropriety in producing them by
the art of the gardener.
In our own time, Reichenbach, judging from appearances only,
described as natural hybrids numerous Orchids. Veitch and others have
* Amen. Acad., ed. Gilibert, vol. i. p. 212.
58 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
confirmed his conjecture by producing by artificial fertilisation the very
same forms which the botanist described. ’ |
It remains only to speak of another respectable but mistaken pre-
judice that has existed against the extension of hybridisation. I am
sorry to say this has been on the part of the botanists. It is not
indeed altogether surprising that the botanists should have objected to
the inconvenience and confusion introduced into their systems of classi-
fication by the introduction of hybrids and mongrels, and that they
should object to hybrid species, and much more to hybrid genera; but
it would be very unscientific to prefer the interests of our systems to the
extension of the truth.
I may mention two cases where scepticism still exists as to the real
nature of certain plants: Clematis Jackmani of our gardens, raised, as is
alleged, by Mr. Jackman, of Woking (‘‘ Gardeners’ Chronicle,’ 1864, p. 825),
was considered by M. Decaisne and M. Lavallée* to be a real Japanese
species, and not a hybrid. This may be so, but there is no absolute
impossibility in the conjecture that the Japanese plant and the cultivated
plant originated in the same way. Again, Mr. Culverwell’s hybrid
between the Strawberry and the Kaspberry has been pronounced to be
no hybrid, but to be Rubus Leesii. But what, I may ask, is Rubus
Leesii? It appears to be a sterile form more closely allied to the Rasp-
berry than to the Strawberry. Is it not possible that Mr. Culverwell
has produced it artificially ? ;
The days when “ species’’ were deemed sacrosanct, and “ systems ”’
were considered ‘“natural,’’ have passed, and Darwin, just as Herbert
did in another way, has taught us to welcome hybridisation as one means
of ascertaining the true relationships of plants and the limitations of
species and genera.
Darwin’s researches and experiments on cross-fertilisation came as a
revelation to many practical experimenters, and we recall with something
akin to humiliation the fact that we had been for years exercising
ourselves about the relative merits of ‘“‘ pin eyes”’ and ‘‘ thrum eyes”’ in
Primroses, without ever perceiving the vast significance of these apparently
trifling details of structure.
It would occupy too much time were I to dilate upon the labours of
Gaertner, of Godron, of Naudin, of Naegeli, of Millardet, of Lord
Penzance, of Engleheart, and many others. Nor need I do more than
make a passing reference to the wonderful morphological results
obtained within our own times by the successive crossings and inter-
crossings of the tuberous Begonias, changes so remarkable that a French
botanist has even been constrained to found a new genus, Lemoinea, so
widely have they deviated from the typical Begonias.
For scientific reasons, then, no less than for practical purposes, the
study of cross-breeding is most important, and we welcome the opportunity
that this Conference affords of extending our knowledge of the life
history of plants, in full confidence that it will not only increase our
stock of knowledge, but also enable us still further to apply it to the
benefit of mankind.
* Lavallée, Les Clématites ad Grandes Flewrs, p. vi-and p. 9, tab. iv.: Clematis
Hakonensis.
HYBRIDISATION AND CROSS-BREEDING. 59
HYBRIDISATION AND CROSS-BREEDING AS A METHOD
OF SCIENTIFIC INVESTIGATION.
By W. Bateson, M.A., F.R.S.,
University of Cambridge.
Ir was with a special pleasure that I accepted the kind invitation of the
Council to address this Conference of persons interested in hybridisa-
tion. Of all the methods which are open to us for investigating the facts
of Natural History there is perhaps none which is more likely to bring
forth results of first-rate importance. Not only is the field a vast one,
but the work is ready to hand. Though the patience and labour needed
are very great, the practical methods are simple, and can be in many
cases carried out by any person who has leisure and is able to carry out
anything accurately. Leisure, accuracy, and a garden of moderate
extent are almost the only equipment necessary for such work. On the
other hand, the scientific importance of the results to be obtained is
transcendent. ;
It is perhaps simpler to follow the beaten track of classification or of
comparative anatomy, or to make for the hundredth time collections of
the plants and animals belonging to certain orders, or to compete in the
production or cultivation of familiar forms of animals or plants. But all
these pursuits demand great skill and unflagging attention. Any one of
them may well take a man’s whole life. If the work which is now
being put into these occupations were devoted to the careful carrying
out and recording of experiments of the kind we are contemplating, the
result, it is not, 1 think, too much to say, would in some five-and-
twenty years make a revolution in our ideas of species, inheritance,
variation, and the other phenomena which go to make up the science
of Natural History. We should, I believe, see a new Natural History
created.
It seemed to me that I could not better make use of this opportunity
than by indicating, as far as I can, some of the aims which I think a
worker in this field should put before him, and the class of work which,
as it seems to me, is most likely to prove fruitful in bringing about
the result I have indicated.
The problem, it is assumed, on which all such work is to be brought
to bear is the problem of species.
I must ask you for a moment to consider the present position of
knowledge in regard to Evolution and the nature of Species—for it is
with a clear reference to the problem of species that breeding experi-
ments, in the first instance, should, in my opinion, be undertaken. We
see all living nature—animals and plants—divided into the groups
which we call species, groups often so sharply marked off that there
can be no doubt where they begin and end; groups often, on the other
hand, so irregularly characterised that no two people would divide
them alike. What are the causes that brought this about and keep it so?
What are the facts underlying this phenomenon of species? For pheno-
menon it is; and, believe as we may that all these forms are related in
60 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
descent, there they are now, grouped into species as we know. How
did this come about ? b
We all know the accepted view. We start from the fact that, since of
all forms of life many more are born than can possibly survive, some
—indeed, nearly all—must perish and leave no descendants. Next we
observe the fact of Variation—that even the offspring of the same parents
are never precisely alike, but vary. Now, since all cannot survive, it is
clear that different individuals have a different chance of survival and of
being represented by descendants. For each individual this chance will
depend on the degree to which its structure and aptitudes fit it to bear
its part in the struggle to which it is exposed. Briefly, on the whole the
fittest will survive and breed.
Lastly, as the places in life that the organisms fit are diverse, so the
forms of the surviving organisms are diverse too.
Everyone who cares at all for Natural History knows this reasoning,
and knows also the difficulties by which its application to the facts of
Nature is beset—how simple the theory seems when thus stated in
general terms, but how hard it is to apply it in detail to a particular
case. ‘
Of all these difficulties the most serious are two. The first
is the difficulty which turns on the magnitude of the variations by
which new forms arise. In all the older work on evolution it is
assumed, if the assumption is not always expressly stated, that the
variations by which species are thus built up are small. But if they are
small, how can they be sufficiently useful to their possessors to give
those individuals an advantage over their fellows? That is known as the
difficulty of small or initial variations.
The second difficulty is somewhat similar. Granting that variations
occur, and granting too that if they could persist and be perpetuated
species might be built up of them, how can they be perpetuated ?
When the varying individuals breed with their non-varying fellows, will
not these variations be obliterated? This second difficulty is known as
that of the swamping effect of intercrossing. Now on each of these two
points the work of the hybridist and the experimental breeder comes in
exactly. It is he who can see the variations arise, and can note their size
and find out exactly how large they are—whether they are great or
small—whether offspring do really differ but little from their parents,
or whether, in certain cases and in respect of certain characters, the
differences in variation may not be very great and definite; whether,
also, the supposed swamping effect is a real one or not, or to what extent
it is real, and in regard to what characters.
I need not tell a body of persons, most of whom have themselves
made experiments of this kind, that in numberless cases both great and
thoroughly definite variations do occur. This much every practical man
now recognises. But we are far from knowing which kinds of variations
may thus be definite and palpable, and which are not. All we know is
that both large variations and small variations occur, some in one
character and others in other characters, and that characters which in
one species may vary greatly and suddenly, in other species vary only
slowly or hardly at all. All this isa matter which comes daily under
HYBRIDISATION AND CROSS-BREEDING, 61
the observation of the breeder—especially the cross-breeder of plants or
of animais. It is to him that we look for first-hand evidence as to the
magnitude of variations.
At this point a word of caution is needed. All those present are
aware of the great and striking variations which occur in so many orders
of plants when hybridisation is effected. As everyone knows, it is to
those extraordinary “ breaks”’ that we owe perhaps the majority of our
modern flowers. Such, for example, are Narcissus, Begonia, Pelargonium,
Gladiolus, Streptocarpus, a great number of Orchids, Rhododendron, the
Cineraria, and the like. JI mention the Cineraria, because I have
personal knowledge of these hybrids, and because I notice that the view
that our garden Cinerarias are not hybrids is being again repeated, in
spite of the clear evidence, both of history and recent experiment, to the
contrary.
With such cases in view some may be disposed to say: “‘ Here are the
great and striking variations we are seeking. These new forms are like
new species—some would even take rank as new genera. May not the
natural species have arisen in like manner by hybridisation?” The
answer to this question, however, is almost certainly No. And herein I
believe most, if not all, professed botanists and zoologists will agree. To
go into the matter fully here is impossible ; but for many reasons, most
of which have often been repeated, there is, I think, no good evidence for
supposing that any natural species, whether of animal or plant, arose by
direct hybridisation. Tempting as it may at one time have been to hope
that we should thus get a short cut to the origin of species, few, I
think, are now sanguine of such an issue. It is not in this direction that
we can look for that advancement in knowledge which I believe will
surely come from the work of the cross-breeder.
I am far from saying that these striking hybrids are without scientific
interest, or that they have no bearing on the problem of species. I wish
only to say that it is pretty clear that they have not the direct bearing
which they would have if it could be supposed that natural species arose
as similar hybrids.
The interest in the cross-breeder’s work lies, as I think, in a somewhat
different field. Whatever view we adopt of the origin of species—pro-
vided that we believe in the doctrine of Descent at all—we believe that
every species has been actually produced from something like itself in
general, though different in some particular. Wherever these two closely
allied varieties exist, the problem of species is presented in a concrete
form: How did variety A arise from variety B, or B from A, or both from
something else? This question involves two further questions :—
1. By what steps—by integral changes of what size—did the new
form come into being ?
2. How did the new form persist? How was it perpetuated when
the varying individual or individuals mated with their fellows ?
Why did it not regress to the form from which it sprang, or to
an intermediate form ?
To those who admit this reasoning it will be clear that the whole
question of the origin of species turns on the relationship of each species
62 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
or each variety to its nearest ullies. We may not yet have an authentic
case of a nascent species that will satisfy all doubts, but unquestionably
we have lots of nascent varieties. If only we make it our business to
observe the way in which these nascent varieties come into being, and
especially what happens when these varieties are crossed with their
nearest allies, we shall have material from which to answer the main
questions of which the Species problem consists.
It is only quite lately that any systematic study of such variations has
been undertaken from the point of view of the evolutionist, and already
some very clear results have been perceived.
As the first difficulty in applyimg the doctrine of Descent turned on
the magnitude of variations, so as soon as careful study of Variation is
begun it is found that large and distinct variations are by no means
rare, and that in certain classes of characters they are indeed the rule.
To this class of variation, in which the variation is found already at
its beginning in some degree of perfection, I apply the term discon-
tinuous.
We are taught that Evolution is a very slow process, going forward by
infinitesimal steps. To the horticulturist it is rarely anything of the kind.
In the lifetime of the older men here present it is not Evolution but
Revolution that has come about in very many of the best-known Orders
of horticultural plants. Even the younger of us have seen vast changes.
It may have seemed a slow process to individual men in the case of their
own speciality. It may have taken all their lives to obtain and fix a
strain; but in Evolution that is nothing. It is going ata gallop !
Whenever, then, it can be shown that a variation comes discon-
tinuously into being, it is no longer necessary to suppose that for its
production long generations of selection and gradual accumulation of
differences are needed, and the process of Evolution thus becomes much
easier to conceive. According to what may be described as the generally
received view, this process consists in the gradwal transition from one
normal form to another normal form. This supposition involves the
almost impossible hypothesis that every intermediate form has succes-
sively been in its turn the normal. Wherever there is discontinuity the
need for such a suggestion is wholly obviated.
The first question was: How large are the integral steps by which
varieties arise? The second question is: How, when they have arisen,
are such variations perpetuated? It is here especially that we appeal
to the work of the cross-breeder. He, and he only, can answer this
question: Why do not nascent varieties become obliterated by crossing
with the type torm
If you study what has been written on these subjects you will find it
almost always assumed that such blending and obliteration of characters
is the rule in Nature Whole chapters have been compiled with the
object of showing how, in a world in which there is such complete
blending, evolution might still go on. There has been a word invented
to expressly denote this kind of blending ; the word is Panmixia, a word
barbarously and incorrectly formed to denote an idea which is for the
most part incorrect likewise. For if instead of abstract ideas the facts
of cross-breeding are appealed to, it is found that so far from this blending
HYBRIDISATION AND CROSS-BREEDING. 63
and gradual obliteration of character being the rule, it is nothing of the
kind. In many characters, on the contrary, it is at once found on cross-
ing that the varying character may be transmitted in as perfect a degree
as that in which it was found in the parent. It need scarcely be said
that there are many structures and conditions which do not thus retain
any integrity when crossed, but there are very many that do. Which
characters are thus unblending, and which blend, must be determined by
careful cross-breeding ; and this knowledge can be discovered in no other
way.
The recognition of the existence of discontinuity in variation, and
of the possibility of complete or integral inheritance when the variety is
crossed with the type, is, I believe, destined to simplify to us the
phenomenon of evolution perhaps, beyond anything that we can yet
foresee. At this time we need no more general ideas about evolution. We
need particular knowledge of the evolution of particular forms. What
we first require is to know what happens when a variety is crossed
with its nearest allies. Ifthe result is to have a scientific value, it is
almost absolutely necessary that the offspring of such crossing shculd
then be exainined statistically. It must be recorded how many of the
offspring resembled each parent and how many showed characters inter-
mediate between those of the parents. If the parents differ in several
characters, the offspring must be examined statistically, and marshalled,
as it is called, in respect of each of those characters separately. Even
very rough statistics may be of value. If it can only be noticed that the
offspring came, say, half like one parent and half like the other, or that
the whole showed a mixture of parental characters, a few brief notes of
this kind may be a most useful guide to the student of evolution.
Detailed and full statistics can only be made with great labour, while
such rough statistics are easily made. All that is really necessary is that
some approximate numerical statement of the result should be kept. The
horticulturist makes a cross: he is perhaps obliged by want of time and
space simply to keep what he wants and throw the rest away ; but some-
times surely he might put down a few words as to what that “ rest ’’ con-
sisted of. If he would do so he would have the gratitude of many a
student hereafter. On looking through the literature of hybridisation
one is saddened by the thought that while so much skill and money
and effort have been expended, for want of a very little more attention to
recording immeasurable opportunities have been missed.
We have seen that it is likely that those experiments will be found
the most fruitful which deal with the relationship subsisting between a
given variety or species and its nearest allies. The essential problem of
evolution is how any one given step in evolution was accomplished. How
did the one form separate from the other? By crossing the two forms
together and studying the phenomena of inheritance, as manifested by
the cross-bred offspring, we may hope to obtain an important light on the
origin of the distinctness of the parents, and the causes which operate to
maintain that distinctness.
Useful contributions to the physiology of inheritance may no doubt
be made by experimental crossing of forms only remotely connected.
Such work, however, will not supply the particular kind of evidence
64 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
most needed. This can only be got by an exhaustive study of the results
of cross-breeding between various forms whose, common origin is not
very distant. Such experiments must, besides, be repeated sufficiently
often to give a fairly extensive series of abservations on which to base
conclusions. Anyone, therefore, who wishes to work on these lines would
do well to restrict himself to an examination of the transmitting pro-
perties of a small group of closely allied varieties or species, and to explore
these properties thoroughly within that group.
Cross-breeding, then, is a method of investigating particular cases of
evolution one by one, and determining which variations are discon-
tinuous and which are not, which characters are capable of blending to
produce a mean form and which are not. It has sometimes been urged
as an objection against this method of investigation that the results are
often conflicting. It has been said that such work will only lead to
accumulations of contradictory evidence. It is, however, in this very
fact of the variety of results that the great promise of the method lies.
When varieties and species are tested by this method it is found that
their mutual relations are by no means alike, and properties are disclosed
which can in no other way be revealed.
In illustration, I will refer to three cases of hairy and smooth varieties.
In each case there is a well-marked discontinuity between the two
varieties ; but, as is shown by the evidence obtained by cross-breeding,
the nature of the relationship* of the two forms to each other is different
in each case, and the distinctness is maintained by different means.
The plants (produced at the meeting) illustrating the following
observations were raised by Miss E. R. Saunders, of Newnham College,
Cambridge, who is carrying out a large series of experiments on this
subject.
The first case is that of MJatthiola incana, a hoary species, and its
smooth variety known in gardens as the Wallflower-leaved Stock. Ex-
periments in crossing these two forms were made by Trevor Clarke, and
briefly described by him in ‘“ Report of Botanical Congress,” 1866.
Amongst other things his investigations showed that on crossing these
two varieties the offspring consisted entirely of completely hoary and
completely glabrous individuals, no intermediate being present. Miss
Saunders’s work entirely confirms thisresult. The type-form used by her
was procured from seed of presumably wild specimens growing in the
Isle of Wight. The glabrous variety was the ordinary garden form the
origin of which is not known to us. In this case discontinuity is
manifested in its simplest form.
The second example is that of Lychnis diuwrna. There, again, the
normal is hairy. A glabrous variety was found by Professor de Vries,
and was by him crossed with the type. All the first generation of cross-
breds inherited the hairiness in its complete form. When, however, these
plants were crossed again with the smooth form, the result was a mixed
progeny, of which some were hairy and others smooth. The same result
*The term “relationship” is somewhat misleading, but I cannot find a better.
It is used to denote not simply the blood-relationship of the forms to each other, but
those physiological relations subsisting between them which are manifested by
experimental crossing. The word is thus used in a sense similar to that which it
bears when we speak of the chemical relations of one substance to another.
HYBRIDISATION AND CROSS-BREEDING. 65
also occurred when the cross-bred plants were bred with each other.
Professor de Vries kindly sent seed of his glabrous form to Cambridge,
- where Miss Saunders repeated the experiments with the same results. In
all the cases of mixed progeny there is a sharp discontinuity. :
The third case is that of Biscutella levigata. A full account of this
important case was published by Miss Saunders in “ Proc. Roy. Soe.’’ 1897,
vol. lxii. p. 11. Briefly the facts are as follows. The species is common
as a hairy plant throughout a great part of the Alps. In a few localities
a variety occurs having the swrfaces of the leaves quite devoid of hairs.
(There are almost always some hairs on the margins and leaf-teeth.)
When present, this smooth form occurs abundantly, mixed with the hairy
type. Intermediates are of rare occurrence. If plants of the two kinds
breed freely together, as in the natural state we must suppose they do,
how is the sharp distinction in their respective characters maintained ?
The result of artificial cross-breeding went to show that of the young
seedlings of mixed parentage some were hairy, some smooth, and a good
many intermediate. But as these seedlings grew, the hairy and the
smooth retained their original characters, while the intermediate ones
gradually became smooth. The transition was not effected by actual loss
of hairs, but after the first few leaves of intermediate character the leaves
subsequently produced were smooth.
In all these three cases there is discontinuity, the intermediates between
the varieties being absent or relatively scarce. Nevertheless, on examina-
tion it is found that the discontinuity is not maintained in the same way
in the different cases. The transmitting powers of the one variety in
respect of the other are quite different in each case, and it must, I think,
be admitted that we have here a fact of great physiological significance.
In each of the three cases enumerated the two varieties are seen to stand
towards each other in a different relation, and in each the mechanism of
inheritance works differently.
From facts like these we perceive how imperfect is the survey of the
characteristics of species and varieties which can be obtained by the
ordinary methods of anatomy and physiology. There can be no doubt
that, tested by the method of breeding and by study of the transmitting
powers, the relation of varieties and species would be shown in an entirely
new light. Weare accustomed to speak of “ variability ’’ as though it
were a single phenomenon common to all living things; and just as the
older naturalists spoke of species in general as all fixed and comparable
entities, so many of the present evolutionists speak of ‘“‘ varieties’: in
general as all comparable. This is a mere slurring of the facts. Not
only must variability in respect of different characters be a manifestation
of distinct physical processes, but, as we have seen, variability, even in
what appears to us to be the same character, may be a wholly different
matter.
Our business, then, is to test and examine these different kinds of
variabilities according to their behaviour when the different varieties
are crossed together. By this means we are enabled to investigate the.
properties of organisms in a way that no other method provides.
If I may be allowed to use a metaphor taken from chemical science,
regarding species and varieties as substances, we may investigate their
.
ne,
66 JOURNAL OF THE .ROYAL HORTICULTURAL SOCIETY.
properties and their powers of entering into genetic combinations, just as
the chemist investigates the powers of his bodies to enter into, chemical
combinations. : .s
To lump all the different manifestations of variation together as
varieties,’’ and to rest there, is to give up in despair.
Similarly, it is certain that what we call “species’’ is a mixture of
different phenomena, or rather of different classes of phenomena con-
founded under one name. I look to the study of cross-breeding to un-
ravel that extraordinary mass of confusion. I look to this method of
investigation to deliver us from the eternal debates on the subject of
what is specific rank and what is not.
On the one hand we have at the present day many who devote them-
selves entirely to discussions of this nature, though they know in their
hearts that their views correspond to no natural fact whatever. On the
other hand, many in disgust and impatience reject the whole thing.
“There is no such thing as species,” say they. Both sides are surely
wrong: there is such a thing as species, and we have to find out what
are the properties of species.
It is true that, as to most species and varieties, artificial breeding is
impossible, but in numerous cases a beginning can be made. Take
merely the phenomenon of local varieties, or local species, or local races,
about which such weary discussions have arisen. Each of these offers a
particular example of the Evolution problem. In numbers of such cases
an investigation of the behaviour on crossing could be practised, and a
very few such experiments would, I venture to predict, do more to
establish true views of the relation of species and varieties than the
labours of systematists will do in ages.
To come much nearer home, we do net know for certain the true
relationships—in this special sense—between the varieties of the com-
monest domestic animals and plants. For example, I have been trying
to investigate these relationships between the several kinds of comb in
domestic poultry. Ihave thus far found no one who can tell me for
certain what happens when they are crossed. The various forms of comb
in our breeds of poultry—simple comb, pea-comb, rose-comb, &¢.—are
important structural features, which differ from each other very much as
many natural species do. ‘The answer generally given is that the result
of such crossing is uncertain—that sometimes one result occurs, and
sometimes another. This, of course, merely means that the problem
must be studied on a scale sufficiently large to give a statistical result.
There is here an almost untouched ground on which the properties of
specific characters can be investigated. Many similar examples might be
given.
True and precise experiments in these fields so ready to our hand
have never been made, We appeal to those who have the opportunity to
use it for the advancement of this fascinating line of research. It is
delightful to form great collections of animals or plants, and to ‘ bring
out a novelty’’ may be an exhilarating sensation; but if anyone will
abandon these well-worn pursuits, and devote himself to experimental
cross-breeding, he will soon haye his reward, for no line of research is
likely to prove more fruitful.
FERTILISATION OF THE GENUS ANTHURIUM. 67
FERTILISATION OF THE GENUS ANTHURIUM.
By Monsieur pE LA DEVANSAYE.
I HAVE published in the Flore des Serres et des Jardins de l’ Europe,
1877, vol. xxii. p. 37, a general article on the fertilisation and hybrid-
isation of Aroidee. Some time after, in vol. xxiii. of the same
journal, at p. 26, I also published an article in which I explained the
evolution of Anthurium Scherzerianum. The two articles confirmed
and illustrated the researches and results then obtained, and even the
hopes of hybridists of those days.
I have also published in the Revue Horticole of Paris special articles
dealing with the same subject. Those to whom these experiences are
interesting, and perhaps of service, will find in the Revue the history
of the genus Anthurium, as well as useful and necessary knowledge ; but
as I followed up and always continued my studies on Anthurium I think it
my duty to draw attention, not only to the two rules which formerly were
supposed to terminate the question, but also to a third one.
Rule 1. In most of the species of the genus Anthurium the fecunda-
tion only operates successfully when the pollen of the same species is
taken from a plant raised from a different batch of seedlings.
Rule 2. The fecundation also operates with success by the application
“of pollen belonging to species of some allied genus; for instance, that
of Spathiphyllum. This assures fecundation, and often gives variation
to the colouring of the flowers, and at other times to the form of the
flowers or foliage. When the variation shows itself in the flowers the
growth of the plant is more vigorous. The contrary happens when it
shows itself in the form and markings of the leaves. If the fecunda-
tion is only done with a view of reproducing and improving the type, the
resultant seedlings coming from carefully selected varieties are generally
more vigorous in point of growth.
Rule 8. Now let me form a third rule, resulting from the experiences
of many years, and to which I think I ought to attract your most
particular attention, as it does not seem to have been noticed or explained
before.
I have already said how one can obtain variations, but in spite of
good crossing it often happens that the first and second generations of
se@llings have no (or very little) new blood in them. Such seedlings
similar only to the type have been abandoned, given up, or destroyed.
It is an error to do this because the variations may eventually result from
a very slight—almost unnoticeable —change of the type. One must have
patience, as the seed of the third and fourth future generations obtained
from these plants may unexpectedly give the desired change.
It very seldom occurs that a variation is produced immediately among
first seedlings of species or of hybrids; the process must be continued.
F2
68 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
A second batch of seedlings will perhaps give 50 per cent., and a third
trial 75 to 80 per cent. ; thus half results may be obtained with the third
generation, and from 75 to 80 per cent. with the fourth. These succes-
sive seedlings of the same variety are necessary to definitely insure the
improvements obtained since the first generation. A careful selection
must always be the principal aim of the raiser, because without
that, far from succeeding in getting progress or improvement and
fixing the definite success, the success itself degenerates and returns to
the type.
Discussion.
Mr. F. W. Bursipas, M.A., V.M.H.: I should like to ask; Monsieur
de la Devansaye whether he has ever obtained a hybrid between A.
Andrianum and A. Scherzerianum.
Monsieur DE LA DEVANSAYE: Never; nor have I ever heard'of one.
HYBRIDISING OF MONSTROSITIES. 69
HYBRIDISING OF MONSTROSITIES.
By Professor Hugo DE VRIEs,
University of Amsterdam.
THE well-known hypothesis of Darwin with regard to the material trans-
mitters of hereditary qualities, called Pangenesis, assumes that each
particular quality is determined by a special transmitting body. This
theory forms, in point of fact, though this is often overlooked, the scientific
foundation of the speculations regarding heredity now so much in vogue.
And in order to obtain starting points for experimental investigation in
this branch of study, it is always best to return to the actual basis of the
theory, since, as Mr. Galton says in his “ Hereditary Genius,” “ it gives a
key that unlocks every one of the hitherto unopened barriers to our com-
prehension of the nature of heredity.” *
In connection with the teaching of Quetelet and Galton regarding the
laws of continuous variability,t Pangenesis leads to the conviction that
new distinctive features arise, not through this, but discontinuously. It is
a question, it is true, of very small steps, but nevertheless they are steps,
and not a gradual improvement of existing characters, as with the
origination of races.
One very important result from Pangenesis appears to me to be that
one and the same quality in various organisms depends upon the presence
of the same material bearer.$
Such material unities may therefore be transferred from one species to
another by means of hybridising. Thence must arise hybrids which
would be just as stable as ordinary species, and which therefore, in certain
cases, could imitate normal species.
If the literature of Hybridity be examined with regard to this question
two facts present themselves. One is that a number of cases are men-
tioned which should be classed under this head ; and the other, that very
little is known of the way in which such a transferring of characters
takes place.
In horticultural practice, especially, there have frequently been trans-
ferred with good results certain peculiarities in newly discovered or
newly imported species into existing hybrid races. The genera Gladiolus,
Caladium, and many others afford examples. In scientific trials also new
and constant forms of mixed character have frequently been obtained by
hybridising; as, for instance,'by Lecoq with Mirabilis, and by Godron with
Datura and Linaria. Focke, however, emphasises the unsatisfactory
nature of our knowledge in this direction in his splendid work on
nf PManzenmischlinge ” (, 484). As is well known, stable hybrids are
the result of the experiment ; but of how it is done, how the transfer of
the peculiarities is effected, we know as yet very little.
Professor Le Monnier, of Nancy, has recently observed a very re-
markable case, and I am indebted to his kindness for the possibility of
* F. Galton, Hereditary Genius, p. 364.
+ Bateson, Materials for the Study of Variability.
t “Unity and Variability,” The University Chronicle, Berkeley, California, 1898.
§ Intracellulare Pangenesis, Jena, 1889
70 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
showing you the result. This is seen in two twisted stems of Dipsacus
fullonum, which owe their twisting to a cross of the common Teazel
with my hereditary race of Dipsacus sylvestris torsus.* As you will see,
the twisting is just as perfectly developed as in the paternal form.tT
In 1896, in the botanical garden at Nancy, there flowered both the
plants in question, which had been cultivated for several years at a
distance of about 100 metres from each other. Pollen could easily be
transferred by insects. From the seed of Dipsacus fullonwm plants were
raised in 1897, among which three in the next summer had perfectly
twisted stems. One of these bore an inflorescence with an involucre
formed of bracts bent upwards; in the other two the bracts were bent
outwards. It is well known that the first is peculiar to D. sylvestris, and
the second form to D. fullonum.
It is to be remarked that in the same year the number of swisha
individuals of D. sylvestris torsus was considerably reduced in Professor
Le Monnier’s garden. Professor Le Monnier was also kind enough to
send me some of the seed of this hybrid: they were sown in April, and
yielded vigorous plants, mostly of the D. fullonwm type.
In this newest example of transferring a monstrosity by hybridising
there is also, as regards the modus operandi of the transfer of the torsion
character, very little known.
For some years, in connection with this position of matters, it has
appeared to me that it would be interesting to investigate a single
case of hybridising carefully and in full detail, and to describe the same.
To this end I chose a very simple case, and one which could be followed
thoroughly—viz. the transference of the lack of pubescence in Lychnis
vespertina glabra into Lychnis diurna. ‘The object was to produce
artificially a hairless form of the latter.
This task is all the more important since the form in question has
already arisen elsewhere in the ordinary way of variation. About 1842
Sekera had found tie hairless form of Lychnis diwrna on a mountain slope
not far from Munchengriitz. It grew there in quantity, and has remained
constant until now, that is, for more than fifty years. He called it at
first L. diwrna glaberrvma, but later L. Preslii. Under the latter name
it is still found in botanical gardens, especially in Prague, in Tiflis, and in
M. Correvon’s garden at Geneva. From Prague Professor Celakowski
sent me, in May of this year, a female plant, and later he sent me some
examples collected for me by his assistant, Dr. Nemec, at the original
station near Minchengratz, for which aid my best thanks are due to
both gentlemen.
I possess, therefore, now the material enabling me to compare my
hybrids with these plants, obviously originated directly from L. diwrna,
and find that, as far as regards the leaves, stems, and flowers, there is no
appreciable difference between the two.
Moreover I have addressed myself to Dr. mil Sekera, Professor of
Zoology at the K.K. Staatsrealschule in Jicin, in Bohemia, a nephew of
ag’. Monographie der Zwangsdrehungen,” in Pringsheim’s Jahrbiicher fiir Wiss.
Bot. vol. xxiii. Part 1, 1891.
t Two twisted stems of the new hybrid and several twisted stems of the paternal
form were shown at the Conference.
{ Lotos, iii. p. 133; Oesterr. Bot. Wochenblatt, 1854, p- 197.
HYBRIDISING OF MONSTROSITIES. 71
the author of the species in question. He had the kindness to give me
all necessary information. He also sent me an authentic specimen
of the Lychnis Preslii collected by his uncle more than forty years ago.
And now I have the pleasure of showing it to you for comparison.
Lychnis vespertina glabra, which formed the starting point of my
trials, does not appear to have been so far described; at any rate, I have
not found it named in the literature at my disposal.*
On the other hand, I found the plant itself at a station not far from
Amsterdam, a station which has since disappeared. This was in August,
1888, in the vicinity of Hilversum, where I collected seed from fully
dried and nearly unrecognisable plants. When the following year I sowed
these in my experimental garden, there appeared a few hairless among
many hairy examples. I collected the seed of the former and sowed them,
and as the culture did not turn out to be a pure one, [| isolated the hairless
form later, during the flowering period. In 1892, in a bed containing
many hundred examples, they were almost entirely true, since only a
single more or less hairy plant was found.
As already stated, I then projected to transfer this hairless condition
to Lychnis diurna, and in that way to produce artificially a L. diwrna
glabra or giaberrima.
The purpose of my experiments can also be thus described—viz. to
obtain, in quite another way, the form known as Lychnis Preslii, which
is recognised by many authors as a good species, and which apparently
has arisen in the Bohemian Alps from ZL. diurna.
My attempt has fully succeeded. I effected the cross in the said
year (1892), f and already in 1894 I had a not inconsiderable number of
hairless examples of Lychnis diurna. The following year this form
proved to be nearly constant, and since then I have cultivated it annually,
and sometimes in large quantities. Among many hundreds of speci-
mens there appeared only exceptionally solitary hairy individuals, so rarely,
indeed, that this may perhaps be imputed to the introduction of weed
seeds into the beds.t
Hybrids between Lychnis vespertina and L. diurna have been obtained
by Gaertner, Focke, and many other investigators.§ The crossing is easily
effected ; the hybrids are fertile, and even apparently no less fertile than
the parent species (Focke). Godron has also crossed Lychnis Preslii
with L. vespertina, and obtaifted hairy hybrids which did not essentially
differ from those obtained by crossing L. diwrna and L. vespertina. The
investigation of the progeny of these hybrids does not appear to have
excited much interest with the said authors. In the second generation
these hybrids, as is the ordinary rule, break into various forms, among
* The pubescence in Lychis vespertina and L. diwrna is essentially the same.
Long many-celled unbranched hairs form a soft covering, among which smaller
glandular hairs are distributed.
{ In order to protect my flowers from insect visits I cover them with parchment
paper bags, which have for years proved excellent for the purpose. These bags can
be got from the manufactory of P. J. Schmitz, in Diisseldorf. Vide a separate paper
on the subject.
{ “Erfelyke Monstrositeiten’’ in Kruidkundig Jaarboek, Dodonea, 1897, pp. 71
and 87.
§ Gartner, Die Bastardbefruchtung im Pflanzenreich, and Focke, Die Pflanzen
mischlinge.
72 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
which, besides the hybrid type, the paternal and maternal characters
appear more or less sharply defined. For my purpose, however, it was
specially desirable to observe the behaviour of the subsequent generations.
When in 1892 I wished to effect the first cross, I sowed to that end
seed of Lychnis diwrna obtained by exchange in the usual way from
botanical gardens. The seed-bed, about one metre square, yielded a brightly
coloured mixture of various forms. Certainly all the plants were normally
pubescent, but between L. diwrna and individuals similar to L. vespertina
there were almost all grades and combinations, both as regards habit of
growth, form of leaf, and colour of flower, as well as the formation of
flower stalks in the first year, or only leafy rosettes.
During the flowering I selected three female plants, which appeared
to me to present the pure characteristics of Z. diwrna. They had the
normal pubescence and dark-red flowers. All the rest were weeded out,
and from these three examples the flowers, which were already open or
had faded, were removed.
I then fertilised these three plants with pollen from my Lychnis
vespertina glabra, and they yielded plenty of seed.
The following year I sowed from this seed a bed of about two square
metres, and had at the flowering period something over 200 examples.
I sowed some more also in the greenhouse, for control and pot culture.
This first generation of hybrids, up to the time of flowering, appeared
very uniform. All the plants were hairy and had the characters of
Lychnis diurna. Closer examination, however, during the flowering
period, afforded opportunity for some not unimportant observations.
In his excellent work upon ‘‘ The Minute Structure of Plant Hybrids,”
Mr. Macfarlane has carefully examined how hybrids are constituted with
regard to anatomical characters which are absent in one of the parents
but present in the other.* He treats of these cases together under the
name of Unisexual Heredity, and deduces the rule that they “ are handed
down, though reduced by half.’ Lychnis vespertina and L. diwrna have
both, upon all parts of the plant, long, soft, many-celled, sharply pointed
hairs, among which there are scattered glandular hairs, rare upon the
stems and more numerous upon the flowers. The hybrid between
L. diurna and the hairless form of LZ. vespertina has shorter and blunt-
ended hairs and a lesser number of glandular hairs, especially on the
stalks.
Of my hybrids, in the first year about two-thirds produced flower
stalks, whilst the remainder only formed rosettes of basal leaves. It is
well known that ZL. diwrna is a perennial species, whilst L. vespertina is
an annual or biennial. But then ZL. diurna also frequently flowers the
first year, as did the mother plants, which germinated and flowered in
1892, when they served for my crossing experiment.
I have especially directed my attention to malformations. It is said,
and pretty generally acknowledged, that hybrids show a greater tendency
towards malformations than do the parental forms. In my seed-beds they
were not rare. In the first place, as regards the number of the pistils,
Gaertner (/.c. pp. 842 and 531) foundin L. diurna x vespertina occasion-
* J. Muirhead Macfarlane, ‘The Minute Structure of Plant Hybrids,’ Trans.
Ioy. Soc. Edin. vol. xxxvii. Part 1, No. 14, 1892, p. 273.
HYBRIDISING OF MONSTROSITIES. 73
ally six, and regards this as an example of increase of the female organs
by hybridisation. I found upon my hybrids a fair number of flowers with
six, and a few with seven pistils. I thereupon examined my stock plants
of Lychnis vespertina glabra and found the same deviation among them.
I had therefore simply overlooked it the previous year, and it is not
to be doubted that, in this case at least, the malformation has not resulted
from the crossing, but is simply inherited from one of the two parents.
It results, however, from this that the same explanation may be true
in other cases: the hybrids are, as a rule, examined more closely than
their parents, and hence more malformations are remarked in them.*
I found furthermore, in my bed of hybrids, tricotyledonous and hemitri-
cotyledonous plants, divided leaves, triple leaves, fasciate stalks and forked
ones, four-petalled flowers (K,,C,Mg), and other malformations. Most
of these divergences, however, I found on careful examination to exist
on one or both of the parental species. They were, therefore, simply
inherited.
The inheritance of malformations by hybrids I have often found con-
firmed by experiments with species of other genera: it appears to me to
form a rule which so far has been too much overlooked as an explanation
of hybrid characters.
The colour of the flowers in my culture bed varied greatly. The great
majority were purple, some were quite white, others dark red, but, as it
appeared to me, not so deeply red as the mother plants in 1892. Between
these three principal colours there were numerous grades of intermediate
tints.
Gaertner also (J.c. p. 241) found the colour of the flowers of his hybrids
to vary: by far the greater number were purple ; a few, however, were white-
flowered.
It appears to me to be very unlikely that the cause of this variability
- is to be found in the crossing. I would rather assume as an explana-
tion that the examples fertilised by me in 1892 in this connection
were not of pure origin. They were selected from a varied mixture of
colours as the finest examples. Regarding their integrity, I had at the
time when I fertilised them no cause for doubting it. 1f they, however,
were hybrids between the warious forms of the mixed lot in question,
one would naturally expect white-flowered offspring as well as red to be
yielded by the seed.
On this view the circumstance, that my hybrids of the first generation
were variable as regards the colour of the flowers, justifies the supposition
that they have simply inherited this variability from their mothers. And
this assumption may possibly embrace the essence of an explanation of
the variability of so many hybrids in their first generations, since only
in the rarest cases have the parental forms, in hybridising experiments,
been carefully tested as to their constancy. It does not suffice that they
appear to be of a constant type. Many hybrids are exteriorly hardly
to be distinguished from one or other of the parents, and therefore
many hybrids may easily be mistaken for true species. In many other
* It has been so in other cases. When I began to give special attention thereto
I found twistings and ascidia to be much more frequent than one would expect from
existing literature. Compare for the first Ber. d. d. bot. Ges. vol. xii. 1894, p. 25;
and for the latter, Dodonea, 1895, vol. vii. p. 129, Over de erfelijkheid van Synfisen.
74 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
experiments I have subsequently been able to test my hybridising
material in this respect, and found the assumption, above given to be
confirmed ; unfortunately, in this case it was no longer possible.
In the horticultural practice of hybridising it is a rule to choose forms
of which one at least is very variable, and hence arises the known multi-
formity of the hybrids.
With regard to the flowers and other important characters, my
hybrids resembled the true Lychnis diurna.
IT come now to the third generation, which I cultivated in 1894. For
this I used seed of the dark-red examples of 1893, which I had fertilised
with pollen from equally dark-coloured flowers, taking care to exclude
insect visits.
But whilst in 1898 all the hybrids had been hairy, this was no longer
the case in 1894. Only about three-fourths were hairy, the rest hairless.
T had 99 hairy and 54 hairless, in all 155 plants, and counted them in
July at the commencement of flowering. The character of the grand-
father, the transfer of which I had had in view, was therefore once again
visible.
Both among the hairy and among the hairless plants there were red-
flowered and white-flowered and _ broad-leaved and _ narrow-leaved
examples; the broad-leaved had the habit of L. diwrna, the narrow-
leaved that of LZ. vespertina. Also, as regards the corolla and the calyx,
there was a similar diversity of form. The parental characters were,
in all imaginable combinations and grades, to be found in the bed of
seedlings.
As confirmation of the above, as regards the inheritance of malforma-_
tions, I found, for instance, a flower with two corollas in one calyx.
Among the vari-coloured mixture, I now sought out my Lychnis
diurna glabra, selecting some male and female examples, which latter
I fertilised with the former, excluding insect visits. They were entirely
hairless broad-leaved plants with the flowers of L. diwrna and with dark-
red petals—characteristics of the grandfather, with the exception of the
entire hairlessness, I failed to find.
The seed reproduced the desired form in the following year (1895)
quite truly—at least as regards the absence of hairs and the other
constant characteristics of my starting plants. Only the colour of the
flowers remained variable. Out of 206 plants there were 13 white-
flowered, or about 6 per cent. The rest were partly purple, partly dark
red.
As regards the pubescence, I have made the following experiments.
As the bed was in the vicinity of that in which the cuiture of the previous
year had been made, its integrity, owing to possible subsequent
germination of older seed, was not certain. I sowed, therefore, a portion
of seed in pans with sterilised soil and raised 390 young plants, all of
which were hairless. The transmitted character could therefore be
regarded as constant.
In the two following years (1896 and 1897) I have carried the new
form through two further generations, choosing always the dark-red
individuals as pollen and seed parents. In 1897 I had a bed of four
square metres, containing about 1,350 plants. Pubescent plants occurred
HYBRIDISING OF MONSTROSITIES. ' 75
in both years as solitary specimens, perhaps through chance introduction
of seed. On the other hand, I did not succeed in reducing the number of
white-flowering plants to any marked extent : it remained about 6 per cent.
If the white-flowering plants be isolated, it is found that they are fully
constant. I fertilised them in 1898 in the first hybrid generation, when
they were all hairy. The hairiness was inherited, as in the red-
flowered plants, in three-fourths of the individuals, but the white colour in
nearly every individual. I fertilised the hairless white-flowered plants with
pollen from same type, and could now, according to the experience given
above, rely upon having the seed of an almost completely true and suffi-
ciently constant new form, Lychnis diurna glabra alba.
It is to be remarked that Sekera mentioned that his Lychnis Presliz
produced no white-flowered examples.
As regards monstrosities, it appeared that split leaves and twisting were
inherited in this race.
To summarise the progress of our experiments, it may be stated that
the fertilisation of Lychnis diurna by L. vespertina glabra succeeded
easily. The hybrids of the first generation were, with the exception
of the colour of the flowers, alike; they were all hairy, only in a less
degree than the mother plants, but otherwise very like it. In the second
generation they broke into the most varied combinations and mixtures,
among which hairless plants of the Lycinis diurna type were easily
found, both red-flowered and white-flowered. ‘These proved themselves
both fully constant from the very moment of their first appearance,
especially in regard to their smoothness, and remained so during all the
succeeding generations. Only the red-flowered seed always yielded about
6 per cent. of white-flowered plants.
The artificial production of Lychnis diurna glabra, which, with the
exception of constancy of the flower colour, seems to be identical with
L. Preslii of Sekera, may therefore be regarded as entirely performed in
the course of nearly four years.
76 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
HYBRIDISATION AND ITS FAILURES.
By the Rev. Professor G. Henstow, M.A., F.L.S., V.M.H., &e.
INTRODUCTION ; DEFINITION OF A SpEcrES.—In endeavouring to
find some clue to the interpretation of hybrids, as to why some species
when crossed fail, while others succeed and bear fertile offspring, it is
desirable to consider what is the present idea of a species. Two con-
siderations were formerly maintained, viz. morphological structures and
a presumable physiological affinity. Thus Bentham defined a species as
follows: “A species comprises all the individual plants which resemble
each other sufficiently to make us conclude that they are all, or may
have been all, descended from a common parent.’’ *
This definition may be sufficient as long as no physiological question
is raised as to the capabilities of different species of the same genus
intercrossing. Dean Herbert, however, soon found that another element
must be considered, and that was interbreeding. Since the practice of
hybridising plants has been extensively pursued ever since he wrote, the
idea has been maintained that if two species would cross and produce
fertile offspring, then they must be regarded as of common parentage,
and as being only varieties of one and the same species. Thus Dean
Herbert writes, referring to experiments of Knight: “The President
adopted in his writings a principle or dogma, which seemed to be then
much relied upon by botanists, that the production of a fertile cross was
proof direct that the two parents were of the same species, and he
assumed as a consequence that a sterile offspring was nearly conclusive
evidence that they were of different species.’’ Hethen further adds: “I held
also... that the production of any intermixture amongst vegetables,
whether fertile or not, gave reason to suspect that the parents were
descended from one common stock and showed that they were referable
to one genus; but that there was no substantial and natural difference
between what botanists had called species and what they had termed
varieties. . . . If two species are to be united in a scientific arrange-
ment on account of a fertile issue, the botanist must give up his specific
distinctions generally and entrench himself within the genera.’’t
Testing the question as to the more or less agreement in external
features between so-called closely allied species being correlated with
fertility in their hybrids, we now know that the general rule may be
formulated that such is the case; yet there are so many exceptions that
the suggestion of Herbert for systematists to follow must be disregarded,
and that they must continue to describe new species and genera solely
by the morphological characters they present.
This is practically what is always done; so that for purely systematic
purposes it would seem that physiological affinity must be neglected
altogether, as, ¢.g., when masses of dried plants are sent to Kew from
some newly explored country.
* Introduction to the Handbook of the British Flora, 1865, p. xxxvii.
+ Amaryllidacee, p. 336.
HYBRIDISATION AND ITS FAILURES. 77
What then is a definition of a species? The following may perhaps
answer the question. A species is known by a collection of, presumably,
relatively constant characters; which may be taken from any or all
parts of the plant. But how many features are required to distinguish a
species from a sub-species or variety is a matter of opinion, and will
always remain debatable. Indeed, the difference between an “ artificial ”’
and ‘‘natural’’ system of classification depends greatly on this point:
for any group in the former is based on one, two, or very few points of
agreement ; in the latter it is generally on as many as possible. Though,
in many cases, a single character may coincide with the strictest affinity,
such as the tetradynamous stamens of the Crucifere, the papilionaceous
corolla of a great section of Leguminose, &c.; and when we come to
other large groups with irregular corollas, we find that systematists
professing to classify plants on a natural system do not hesitate to drop
into an artificial one when it suits their purpose. For example, Liliacce
are separated from Amaryllidacee solely by having a superior ovary.
Yet elsewhere we can find both inferior and superior ovaries in genera
of the same order, as in Samolus and Primula of Primulacee ; or, again,
in species of the same genus, as Saxifraga tridactylites, S. wmbrosa, and
half-superior in S. granulata.
But although the two orders mentioned above are separated on
account of this single character alone; yet, testing it by crossing, no
known attempt to unite two members of these orders has ever yet
succeeded, as far as I can hear from experimenters. It would seem,
therefore, that they have been differentiated at so remote a period that
they have lost all physiological connection.
So too with genera; the corolla of Snapdragon only differs from
Toadflax in having a small pouch at the base, which elongates into a
spur in the latter. I can hear of no cross raised between them. Now
Ehododendron, Rhodora, and Azalea are as much entitled to be called
genera respectively, if systematists may separate genera by such slight
differences as the above; and there is no reason why they should be
merged into one, solely because they will interbreed : for if interbreeding
is to be a test, then those polymorphic forms of one and the same
species that cannot be intercrossed with complete fertility ought to be
separated, as of Lythrum; to say nothing of Linwm perenne and some
Orchids which cannot bear seed with their own pollen.
Ehododendron jasmviniflorwm has a corolla as unlike that of a typical
Rhododendron as can well be imagined—indeed, Mr. Burbidge likens it to
Erica Aitonii—and might be regarded, therefore, with justice as a
different genus; since systematists separate the genera of plants with
irregular corollas entirely by that organ in many cases—as in the
Scrophularinee. Now it will cross readily with R. Javanicwm, which
has the typically formed corolla; but not with the American, or species
of other countries. On the other hand, Mr. Burbidge crossed R. jasmini-
florum with an Indian Azalea as the male parent.
Let us take as another instance, the “genera” Lelia and Cattleya.
Species of these two have yielded many so-called “ bi-geners”’ ; but are
they worthy of the name? Now the variations in the forms of the
flowers of different species of each of these two genera do not differ more
78 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
among themselves than between different species of these genera. In other
words, they would form one genus if the perianth alone were the basis of
classification. But this is not the feature relied upon, but the nwmber
of pollen masses—i.c. a single feature, and therefore, so far, an artificial
character—just as Linneeus would unite the Ash tree, Veronica, a Grass,
and the Duckweed because they have two stamens. Turning to the
Genera Plantarum” we find that Cattleya has four pollinia. Then
follow three genera with eight in two series; those of the upper series
very often much smaller than the lower. Then comes Lelia, also with
eight pollinia in slightly unequal series.*
Here, then, is obviously a closely graduated series based on a single
character, and a purely artificial one. The classification is therefore
not strictly natural, though the series of so-called ‘“‘genera’’ may be.
Consequently, though we may call the cross-products ‘“‘ bi-geners,”’ it is
only so from Bentham and Hooker’s classificatory point of view.
These observations apply to Hpidendrum and Sophronitis as well.
Similarly with the so-called bi-gener between Lapageria and Philesia.
Those genera stand together in the “ Gen. Pl.,”” being No. 10 and No. 11
in Liliacee: both are mono-specific, and both live in Chili. The
distinguishing features are recorded as being, in Lapageria, ‘‘ Leaves 3-5-
nerved,” and ‘“‘ the segments of the perianth sub-equal.’’ In Philesia,
“ Leaves 1-nerved,” and “ the exterior segments of the perianth are much
shorter than the interior.” But much ereater differences in nervature
occur in species of Plantago ; and also between the outer and inner
whorls of the perianth of species of Iris.
Consequently, to be true to principles of natural classification, it
would seem that the above two genera should be regarded simply as two
species of the same genus.
Once more, in the “Gen. Pl.” Gloxinia (gen. 6) and Achimenes
(gen. 7) belong to the sub-tribe Gloxinee ; while the genera Gesnera (gen.
18) and Sinningia (gen. 19) are in the sub-tribe Hugesneree. There is,
however, no special feature to separate them—a fact which Dean Herbert
perceived and discussed at length some seventy years ago.
He mentions also that Simningia and Gloxinia produced fertile
hybrids.
Gloxinera—i.e. Gloxima x Gesnera—was raised in 1894.+
Selenipedium and Cypripedium are genera which Bentham and
Hooker admit to be scarcely distinguishable except by the ovary being
one-celled in the former, from a want of cohesion of the placentas,
and its habitat, viz. South America, the nearest home of the latter
being Mexico.
Though it has been found difficult to cross these, yet Mr. Swinburne,
of Winchcombe, near Cheltenham,$ raised small plants from S. Schlin
x C. Spicerianum, male parent; also between S. Donvinianum x C. Cham-
berlaint. The plants were raised in 1896, but have not yet flowered.
* See observations by Mr. C. C. Hurst relative to this matter, Jowrn. R.H.S.
1898, p. 475.
+ On Hybridisation amongst Vegetables.
{ For successful Bi-geners and Hybrids in Gesneriacee, see Burbidge’s Prop. and
Improv. of Cult. Plants, p. 331 seqq.
§ Gard. Chron. Oct. 10, 1896, p. 435.
HYBRIDISATION AND ITS FAILURES. 719
Bi-GENERIC FarnurEs.—lIf species of the same genus, but natives of
widely distinct countries, often refuse to cross; d fortiori, would it be
anticipated that genera of the same order would fail? The genus
Hippeastrum has been used for attempted crosses with other genera from
warm countries, of the order Amaryllidacee. Thus, it has failed with
Sprekelia, the former being of tropical and South America; the latter—
a monotypic form—of Mexico.
Hippeastrum has’ failed to produce healthy progeny with Clivias of
South Africa. Mr. Wright observes: ‘This attempted cross was success-
ful so far as the actual cross went; but the progeny were so weak that the
seedlings only lived: about a year. This proved to be the case with three
distinct lots of seeds.”’
M. Rodigas, of Ghent, makes a suggestive observation: “The decay .
in the persistent leaves of many plants of Clivia may be attributable to
the employment of pollen from Amaryllis and Hippeastrum, the leaves
of which are deciduous.” *
Hippeastrum has also failed with Vallota and Hemanthus, both of
South Africa. Attempts have been made to unite Hippeastrum with
Urceolina (Andes) and Pancratiwm (Mediterranean regions) without
success; but as these genera belong to a different sub-tribe, as well as
widely different countries, the probability of their having any physio-
logical or constitutional affinity was proportionally diminished. Similarly,
attempts to cross Griffinia, allied to Hippeastrum, with Hucharis and
Urceolaria failed.
Of other genera of the Amaryllidacee of widely different countries that
have failed are Amaryllis Belladonna (South Africa) with Lycoris (Japan,
China, &c.).
Of two genera of the same _ sub-tribe—Cyathifere—Pancratium
canariense failed with Hucharis grandiflora (Andes).
But genera from the same country may fail, as Cyrtanthus with
Vallota, genera closely allied and both of South Africa. Similarly,
Zephyranthes brachyandrum has failed to cross with Hippeastrum
stylosum, H. sub-barbatum, H. equestre, and H. vittatwm, though
these two genera are very closely allied; but while Zephyranthes are
natives of tropical and sub-tropical America, Hippeastrwm belongs to
South America.
Crinum and Amaryllis (gen. Nos. 26 and 27 in “‘ Gen. PIl.”’) have failed
to cross as far as the following species are concerned: C. Moorei,
C. fimbriatulum, and C. zeylanicum. F
A large number of bi-geners have been attempted at the Utrecht
Botanic Gardens, but without results. The following is a selection :
Helleborus x Caltha, Caltha x Eranthis, Caltha x Nymphea, Caltha x
Peonia, Fuchsia x @nothera, Bellis x Cineraria, Hemerocallis x Lilium,
Pancraticum x Crinum, Phalienopsis x Vanda, &e.
Of other genera in which the morphological characteristics would
warrant an d priort probability of success in crossing, but failed on
practice, is Streptocarpus x Didyncarpus ; but while the former genus
* Gard. Chron. Jan. 5, 1895, p. 16.
t Other failures among genera of Amaryi~LIpace® are Elisena longipetala x
Hymenocallis calathina; of Irtpex, Cypella plumteax Herbertia pulchella, Iris
Robinsoniana x Marica cerulea; of AroipE®, Alocasia x Caladium.
80 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY,
is found in South Africa and Madagascar, species of the latter are natives
of the Malay Archipelago, and E. Asia ; so that in this case constitutional
affinity does not correspond with morphological resemblances.
That Streptocarpus should fail to be crossed by Gesnera was more
likely, as, besides being natives of different hemispheres, they are distantly
located in the ‘Genera Plantarum.’
Of sub-genera that failed to cross, Mimulus x Diplacus may be
mentioned.
Though Hpidendrum radicans has been successfully crossed as male
with Sophronitis grandiflora female, yet S. violacea has been crossed with
E. radicans and E. Obrienianum without result.
CoNSTITUTIONAL AFFINITY AND SteRILITy.—Admitting the fact that
the closer agreement there may be between the forms of two species, the
more likely is it that they will cross, yet it is not universally true; so
that, leaving ‘morphological affinity’ out of the question, we have to
depend on, for want of a better expression, what one may call “ constitu
tional affinity,’’ cautioning the reader that this is a phrase which covers
our profound ignorance of the true nature of physiological aftinity !
Dean Herbert observes: ‘Some crosses are sterile and some quite
fertile, without any apparent reason, except the greater or less approxima-
tion of constitution in the parents; and that the cross-bred plant which
has seemed for a long course of years to be absolutely sterile becomes
under some circumstances productive.” *
The last sentence is important, for it introduces another fact, that
sterility and fertility are not absolute features, but vary in the same
plant according to circumstances; and it applies to self-fertilisation as
well as crosses and hybrids. Thus, Darwin found that the dimorphic
forms of Linwm perenne were self-sterile ; but Mr. T. Meehan, of German-
town, Philadelphia, had one form only in his garden, which never set
seed for fourteen years; yet, then, one branch bore flowers which became
homomorphic and immediately fruited. Under cultivation Primulas of
various kinds, as P. sinensis, can become self-fertile iv a similar way.T
Eschscholtzia californica was self-sterile in Brazil, bus acquired great
self-fertility in England in three years—nearly 87 per cent. +
Dean Herbert says elsewhere: ‘ Experiments have confirmed the
view to such a degree as to make it almost certain that the fertilisation
of the hybrid or mixed offspring depends more upon the ¢oustitution than
the closer botanical affinity of the parents.” $
He illustrates this by the genus Crinwm, showing that while certain
nearly—i.e. morphologically—allied forms are difficult to produce fertile
hybrids, others so distinct as to have been placed in different genera do
so, the interpretation being that the latter were aquatic plants, and
therefore presumably of the same constitution ; whereas in the former
case the ineffectual cross was made between an aquatic and a terrestrial
form frequenting dry localities.
This hybrid between C. capense (aquatic) and C. scabrum continued
for sixteen years to be sterile, but ‘‘ produced one good seed in 1884, and
* Amaryllidacee, p. 340.
t Origin of Floral Structures, p. 209.
g
Ibid. p. 320.
Amaryllidacee, p. 342.
HYBRIDISATION AND ITS FAILURES. 81
again in 1835.” He mentions another instance of a sterile hybrid, called
C. submersum, growing near Rio Janeiro in company with a small variety
of C. erubescens. It was exactly intermediate between this species, which
is aquatic, and C. scabrum of high ground.
Of dissimilar species readily crossing, Dean Herbert * alludes to “ the
prickly, angular Cereus speciosissimus, the flexible C. flagelliformis or
Whip-plant, and the unarmed C. phyllanthocides, are nearly the most
dissimilar ; yet they have produced mixed offspring, which readily bears
edible fruit of intermediate appearance and flavour.”’
As illustrations of failures through constitutional differences, Mr.
Buffham could obtain no success between perennial and annual species
of Sunflower. With Rhododendrons, Mr. Veitch could get no hybrids
between the East Indian hybrids and the Himalayan section, nor with
the Ff. arborewm section.
With Primroses, all British species fail to cross with Primula sinensis
either way; and a significant fact is that all kinds of cultivated P.
sinensis fail now to cross satisfactorily with the original wild form,
according to Mr. Sutton’s experience; for though he was successful in
obtaining ten plants from two crosses between P. sinensis ‘* Chiswick
Red,”’ the female, and the original P. sinensis as male parent, all ten
plants were very weak, and all died while in the first stage of flowering.
Messrs. Sutton, however, have never been able to obtain any seed from
the original P. sinensis when pollinated by any other variety. It is self-
fertile. P. sim.“ Stellata,” apparently the same as ‘‘ The Lady,” and
representing an early stage of cultivation, can cross (either way) with
the normal cultivated forms.
P. obconica failed to be crossed with P. sinensis by Messrs. Sutton ;
but with Mr. Wright, of Chiswick, it so far succeeded that while the
progeny resembled the mother; that of the second generation indicated
the effect by bearing flowers with four, five, six, or seven petals, and
once eight ; no such disorganisation occurred in the first generation.
It would therefore seem to be a common, if not a general, rule that -
species of different countries present greater difficulties in crossing than
those of the same country, which probably grow under similar conditions.
Thus, Fuchsia procumbens of New Zealand refuses to unite with the
South American species, which readily intercross. Mr. W. G. Smith
tells me that the outline of the pollen-grains of the former species is
spindle-shaped, while of the latter it is a spherical triangle.
Indian Azaleas are difficult to unite with the deciduous species of
Japan.
Begonia “ sempertiorens”’ section will not be successfully crossed
with the tuberous section.
Begonia ricinifolia x B. tuberosa (hyb.) produced seeds but no plants
at the Utrecht Botanic Gardens.
As instances of failures between species with marked morphological
differences, yet residing in the same country, may be mentioned the
“ Fancy” Pelargonium with the scarlets. Krelage failed also in attempt-
ing Pelargoniwm gibbosum with P. zonale. Other failures between
species crossed by this experimenter were Aristolochia elegans x A. bra-
* Anuryllidacee, pp. 343 and 345.
G
82 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
ziliensis; Stanhopea eburna x S. tigrina, which bore fruit, but it
decayed before ripening. .
With regard to Cypripediums, Mr. Veitch sends the following obser-
vations as the result of his experience. No progeny has yet been raised
from crossing the species of Selenipediwm with Cypripediwm (Sect.
Coriacea, Benth., Paphiopediwm, Pfitzer), or vice versd, or between
species of either of these sections and the hardy cypripedia ( foliose,
Benth.).
The species chiefly used in the experiments were, of Selen., well-nigh
all in cultivation ; of Cyp. (coriacee), the group of species known among
horticulturists as the barbatwm section, distinguished by their one-,
rarely two-, flowered scapes, their tessellated foliage, and their semi-
lunar staminode ; and the group called the Stonei section, distinguished
by their many-flowered scapes, their pendent, narrow petals and shield-
shaped staminode ; and in Cypripedium ( foliose), our native species. C.
Calceolus, and the American species C. spectabile, C. pubescens, &ce.,
have formed capsules in abundance, but they were invariably barren.
Interesting eXperiments upon the capability of pollen have been made by
Professor EK. Strasburger, which show that very similar effects of imperfect
fertilisation can be produced where it cannot be said that there is any
affinity at all. Thus, he found that Lathyrus montanus would put out
pollen-tubes, which will enter the ovary of Convallaria latifolia ; those of
Agapanthus wmbellatus will penetrate deep into the style of Achimenes
grandiflora. Those of Fritillaria persica will not only enter the ovary
of species of Orchis, but will even excite the development of the ovules
and will cause them to begin to swell. The pollen-grains of Achinvenes
grandiflora will not, on the other hand, penetrate the stigma of
Agapanthus.
The possibility of the pollen-grains of one species or genus developing
tubes on the stigma of another species or genus does not depend upon the
possibility of hybridisation between them. As a rule, the pollen-tubes
penetrate the style or ovary to a depth proportional to the relationship of
the species ; though Lathyrus montanus and Convallaria, as mentioned
above, are exceptions.
That varieties of the same species exhibit greater capacity for exciting
the development of pollen-tubes than species of the same genus, depends
simply on a greater resemblance in the composition of the nutrient
material, furnished to the pollen grains and tubes by the stigma and
style.
Hybridisation is an evidence of sexual affinity, but its non-occurrence
is no evidence of the absence of affinity.
ExcesstvE Preporency, or Fause Hysprivs.—The question as to
the influence of the male or female parent respectively has often engaged
the attention of hybridisers. In some features one parent has seemed
to predominate, in others the other parent; while perhaps as a general
rule neither does so, but the progeny are strictly intermediate between
them.
Experience, however, leads one to the conclusion that, starting from
the intermediate condition, either parent may predominate in every degree,
up to an apparently exact imitation of itself in the hybrid offspring. In
HYBRIDISATION AND ITS FAILURES. 83
other words, its influence has been so prepotent as to arrest all trace of
the other parent in the offspring.
M. Millardet, who studied the hybrids between Alpine and American
Strawberries, called these extreme results ‘‘ False Hybrids.” *
This peculiarity was early observed, for Gaertner records the fact that
Datura Stramonium x D. ceratocaulis bore two fertile plants which
resembled the female except in height. Their seeds produced D. Str.
normal.
D. Levis x D. Str. bore: forty plants resembling the male parent.
Mr. Burbage records somewhat similar results as obtained by Mr.
Anderson-Henry with Veronicas,{ observing ona particular instance: ‘I
have seldom seen two hybrids with so much of one parent and so little
of the other.’ Mr. T. Meehan, of Germantown, Philadelphia, has
experienced the same thing; for example, he says that ‘‘ Disemma
aurantia x Passiflora cerulea as the male parent, gave rise to a progeny
which was simply Disemma,t with no trace of the Passion-flower.”
Again, Fuchsia arborescens x garden hybrids ‘‘ bore seedlings which,
both in foliage and flowers, were J’. arb., and nothing more.’’ Lastly,
Quercus palustris x . imbricaria resembles the female parent entirely,
except that it has numerous entire leaves as well, which are like those
of Q. imb., but in venation and all other characters it is wholly
Q. palustris.
In speaking of Fuchsia longiflora x F'. fulgens, Mr. Meehan observes
that ‘several dozen plants were raised, all being from one berry ; but no
two of the many seedlings were alike. Some nearly approached the
female, others the male parent. None could fairly be said to be inter-
mediate.”
Herr Max. Leichtlin found from his experiments that ‘the female
parent gives to the offspring form and shape of the flowers; while the
male parent gives more or less the colouring of the flowers ; and if it is
richer and freer-flowering than the female, this property is transferred to
the offspring.’ To whatever degree it may be true for certain plants, no
absolute law appears capable of being formulated. Thus, Dr. Denny
remarks on Pelargonia: ‘The result of my experience, derived from
experiments as regard the relative influence of the parents, certainly
tends in the reverse direction to my previous ideas, which were derived
from books, from which I gleaned that the form of the flower and consti-
tution and habit of the plant were inherited from its mother; while the
colour of the flower only was supposed to be conveyed by the father.
The recorded results of my crossings indicate an immense preponderance
of influence over the progeny on the part of the father in all respects—
in colour and in form, in the quality, in size and substance of the flower,
as well as in the production of variegation of the foliage, and in the habit
and constitution of the plant also, provided the plants employed were of
equal strength.”’
Dr. Denny “ fertilised without much difficulty a variety (Peltatwm
elegans) of the Ivy-leaved section by the pollen of the zonal. . . . The
* Hybridation sans croisement, ou Fausse Hybridation (1894). See Gard. Chron.
1894, Nov. 10, p. 568.
+ Op. cit. p. 537.
t A section of Passiflora (Gen. Pl. vol. i. p. 811).
84 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
foliage [of the cross] resembled almost entirely that of the mother ;
which is the reverse of my experience of the results produced between
varieties.’ *
Mr. C. C. Hurst experienced the same thing in Orchids. Thus he
writes: “In May, 1891, Mr. R. Young, of: Sefton Park, Liverpool,
crossed Cypripedium barbatum with pollen of C. nivewm. Fourteen
hybrids were raised. . .. Every one of nine which flowered was C. bar-
batum, without a trace of the father parent, C. nivewm.”’ T
Mr. James Douglas has also shown how the same phenomenon occurs
in the case of Carnations.
Mr. Moore, of the Royal Botanic Gardens, Glasnevin, informs me
that he has never succeeded in crossing Lachenalia pendula with any
other species or variety. On one occasion he thought he had succeeded
in doing so with Z. awrea, but the seedlings were only aurea. He also
failed to raise a hybrid between Helleborus niger and any other species.
When crossed with H. orientalis the progeny proved to be H. mger.
’ Non-rEcrprocity iv Hyprips.—As a general rule, it may be stated
that hybrids are not only intermediate in character between their parents,
but that they are alike when either parent is the male or female. But
it is not always so; and the peculiar difference may occur of a species
being readily crossed with others, yet refusing to cross them in return, or
vice versd. Thus Mr. J. Scott says: ‘‘I inserted pollinia of Oncidiwm
microchilwm into the stigmatic chamber of eight flowers of O. ornitho-
rhyncum; of these, three produced capsules containing about 21 per cent.
of good seed. I also tried the converse experiment, and applied pollinia
from O. ornithorhyncum to the stigmatic chambers of twelve flowers of
O. microchilum, but in this case I failed in causing a single capsule to
swell.” §
Mr. Burbidge || records a similar fact of Rhododendron EHdqworthii
as narrated by Mr. J. Anderson-Henry, who writes: ‘‘ While it has been
repeatedly made the male, it has never submitted to become the female
parent... . &. Nuttalli behaved in the same manner.’’ He further
adds: ‘This remarkable circumstance of non-reciprocity has perplexed
and defied me in innumerable instances throughout my long experience
in these pursuits.”’
Mr. E. Scaplehorn, of Mayford, Woking, writes me with regard to
Clematis coccinea: ‘1 understand, from experiments made here respect-
ing the new C. coccinea hybrids, that C. coccinea when used as the female
parent did not produce any material results ; but only when the various
varieties of C. Jackmanni were crossed with the pollen from C. coccinea,
was the production of these hybrids possible.”
Again, Mirabilis longiflora x M. Jalapa proved a failure, though the
reciprocal hybrid was a success.
Professor I’, Parkman records his experience of a like kind with Lilies.
* «On the Relative Influence of Parentage,” Journ. R.H.S. New Series, vol. iv.
pp. 18, 19, and 23.
+ “ Notes on Some Curiosities of Orchid Breeding,”’ Journ. R.H.S. 1898, p. 442.
t “ Cross-fertilisation of Florists’ Flowers,’ Journ. R.H.S. 1897, p. 205.
§ Journ. Lin. Soc. xv. p. 164, where other instances are mentioned.
|| Op. cit. p. 299.
{ Gard. Chron. Jan. 5, 1878, p. 19.
HYBRIDISATION AND ITS FAILURES. 85
Oneidiwm Papilio x Phalenopsis grandiflora was crossed, but failed
at the Utrecht University Botanic Gardens; but the reverse cross has
succeeded, the seeds of which have been saved and sown, but the result
is at present unknown.*
Non-reciprocity also occurred in Epidendrum. Thus Mr. Veitch
found that L. radicans could be successfully used as the male parent with
E. evectum, Cattleya Bowringiana, Lelia purpurata, and Sophronitis
grandiflora; but when itself has been used as the seed-bearer the cross
invariably failed. Trials have been made with the pollen of its own
progeny, as Hpiphronitis Veitchii (=H. radicans, male; Sophronitis
grandiflora, female), and of HE. Obrienianum (EH. radicans, male; E.
evectum, female), but with no better result. Yet when pollinated with
its own pollen it seeds freely.t
INFERTILE “CROSSES”? BETWEEN VARIETIES.—As different species
of one and the same genus may or may not yield successful hybrids—
thus, while the “ Fancy’ Pelargonia and the zonals mostly breed together,
respectively, yet these two sections will not unite—so, too, is it the
case with varieties. Mr. C. E. Pearson writes me on crossing Pelargonium
vars.: “The French seem to have differentiated three strains of
zonal Pelargoniums, two of which are quite sterile with our own. The
first failure was with a variety called, I think, Dame Blanche (some
twenty years ago), which refused to cross, either as male or female, with
our English varieties, but was fertile with its French contemporaries.
The second was with the ‘Bruant’ race of zonals, a strain with huge
trusses, but very irregular pips with large windmill-sail petals. I have
not tried all these, but those I did were all sterile, both ways.
“The most recent French strain, originating in Jules Chrétien,
crosses freely with ours.
‘““T may also mention that there is a close relation between colour and
fertility in some zonals, the very dark crimsons being so nearly sterile as
to make seed-raising difficult, the sterility being in proportion to the
depth of the colour.’
This last observation refers to self-fertilisation, and agrees with
Darwin’s. It is because the flowers are strongly proterandrous. In the
paler varieties, as ‘‘ Christine,” they are more nearly homogamous, and
consequently are very self-fertile.t
Dr. Denny found similar inconsistencies among varieties of Pelar-
gonia in 1873. He writes: ‘I have alluded to the antipathies and
affinities we find to exist, without any explicable cause; for instance, I
have found it impossible to fertilise three or four varieties of the scarlet
Pelargonium (viz. the Duke of Cornwall, Dr. Muret, Beauté de Suresnes,
and all that section of the doubles which sprang from Beauté de Suresnes),
which to all appearance are mere varieties of the zonal section—sayve
with one another.’ §
A florist informed me (in 1880) that he found the “ rough-leayed”’
fancy Pelargonia, the flowers of which have a blotch-on all five petals
* Communicated by Mr. Krelage, from Mr. J. K. Budde, the curator.
t+ See also paper by Mr. C. C. Hurst, Gard. Chron. Jan. 7, 1899, p. 14 seqq.
t See Darwin’s Cross and Self Fertilisation of Plants, pp. 142 note and 352.
§ Op. cit. p. 22.
86 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
would not cross with the smoother-leaved forms, the flowers of which
have blotches—at least distinct—on two petals only. \I do not know how
far this has been corroborated, if at all.
PartiAL Hysripisation.—A feature not infrequently observed by
hybridisers is that a result of foreign pollen applied to the stigma of a
different species is that it may take effect in varying degrees without
securing any fertilisation of the ovules at all.
One of the first botanists to note this fact was Wichura in the case of
Willows, in which the following degrees of failure were observed :—
1. “The catkins submitted to hybridisation wither as soon as the
flowering is complete, and fall off.
2. ‘*The ovaries swell and mature, but do not contain a_ trace
of seed.
3. “ The ovaries are quite filled with the silky hairs which clothe the
funicle of the seed, which contains no embryo.
4. “Seeds are present, but small, feeble, and~- incapable of
germination.
5. “Seeds apparently perfectly developed, but do not germinate.
6. ‘ Seeds germinate, but the young plants are weak, and wither in a
short time without further development.
“The gradation in the number of seeds was very various. Sometimes
the seeds were few, but fertile and active; sometimes, on the contrary,
numerous, but with only a few fertile mixed with a number of abortive
seeds ; sometimes tolerably numerous, without any such admixture ; but,
in general, hybrids yielded on the whole a smaller number of seeds than
plants impregnated with their own pollen.’’ *
The above quotation was published in 1866; but Dean Herbert
experienced the same results with Alstroemerias, and records Mr. Bidwell’s
crossing Passiflora cwrulea with P. On unrane which bore a fine orange
fruit, but devoid of seeds.
Similar results have occurred repeatedly since then with other plants.
Thus, just as Wichura found that silky hairs were the sole result of
poilination in Willows, so is it in Orchids; as, e.g.,in an attempt at
hybridisation by Mr. Veitch in the case of Phalenopsis Luddemanmana
x P. Schilleriana, amabilis, and grandiflora. There was no seed, but
hypertrophy of the placental hairs, giving the appearance of a pod full of
cotton wool.t This has also occurred with many other Orchids.
Phalenopsis grandiflora x Stanhopea tigrina, as well as Stanhopea
eburna x S. tigrina, developed fruits; but no seed could be obtained
which would germinate in the Utrecht Botanic Gardens.$
That the pollen may only affect the fruit is a well-known phenomenon.
Thus, for example, Dr. Bonavia crossed the native Pumpkin of India,
called Koomrd, with the American Squash pollen. The ovary enlarged
and came to maturity, but did not contain a single seed. When it is
fertilised with its own pollen, it is full of good seed.
Mr. Veitch observes that ‘neither the Cattleyas nor the Brazilian
* Abstract in Journ. R.H.S. New Series, vol. i. p. 63.
t On Hybridisation amongst Vegetables.
¢ The reader is referred to Origin of Floral Structures, p. 165 seqq., for a dis-
cussion on the influence of the pollen-tube upon the ovary.
§ Communicated by Mr. Krelage.
HYBRIDISATION AND ITS FAILURES. 87
Lelias will cross freely with the Mexican Lelia albida, autwmnalis
majalis, rubescens (better known in gardens as acuminata), ke.
Numerous crosses have been effected both ways, and capsules have been
produced, but the seed has always proved barren.’’*
Similarly, Mr. Salter, of Woodhatch, writes me: ‘ Dendrobium
Phalenopsis, var. Schroederianum, was crossed with D. Ainsworthii,
D. formosum, D. Cassiope, and D. heterocarpum, and the fertilisation
seemed perfectly ‘successful; and the pods swelled in the ordinary
manner until the ripening season. When, however, they were split
open, there was no seed, only a kind of fluff [hypertrophied hairs| upon
the internal ridges of the pods.”
Sophronitis violacea and S. grandiflora have both been crossed.
reciprocally, by Mr. Veitch; but although capsules were formed no
fertilisation had taken place.
Empty capsules also resulted from crossing Vanda tricolor with species
of Angrecum and Phalenopsis. So too between species of Phalaenopsis.
P. Luddemanniana, the male parent of some of the finest hybrids of
this genus raised, has been crossed with the pollen of well-nigh every
species of P. in cultivation; but nothing has yet resulted therefrom.
The application of the pollen of species of P. to the stigma of
P. Ludd. stimulates the ovary into growth, but seems to be impotent
to fertilise the ovules. Similar results have attended P. violacea when
used as the female parent, with the single exception of the hybrid
P. Ludd. violacea raised from it, and P. Ludd., male. The above result,
which is Mr. Veitch’s experience, was repeated in the cases of Cyii-
bidiwm male x C. Lowianum, C. gigantewm, and C. Traceyanum; and
several other genera gave similar results.
Lastly, Campanula Van Houttei, believed to be a hybrid, as it is
generally barren, was crossed by Mr. E. Scaplehorn with C. mirabilis.
The ovary enlarged and contained ovules, but the latter were deformed,
yet much larger than in the case of those not crossed, proving that a
partial impregnation had taken place. A similar result followed on
crossing the first named with C. medium.
A general result is seen in a hybrid, or bi-gener, vegetating freely
and healthily, but failing in various degrees in its reproductive system.
It may show in its leaves &c. every intermediate character, or none at all,
being exactly, to all appearances, like one of the parents. Results of
this kind have followed attempts to cross Geraniums with Pelargoniums,
Abutilon with Hibiscus, Raspberry with Strawberry, and Gooseberry with
Black Currant. With regard to the last two, the former of them has
flowered but borne no fruit, while the latter has borne fruit as well.
Fause INFERENCES FROM FaILuRES.—That a cross may fail in one
season and not in another shows that no absolute rule can be laid down,
as in the following case in the experience of Dr. Bonavia, who writes me
as follows: ‘ When in India I imported a Dutch Hippeastrum. It
flowered. At the same time I had a large number of Lucknow
Hippeastrums in flower. I endeavoured to cross the Dutch H. with
the Indian ones; but no result occurred either with the Dutch pollen or
the reverse. I tried the same experiment in the next year, again with
* Gard. Chron. May 16, 1885, p. 630.
88 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
no result whatever. But in the third year I tried again, both ways, and
I got a number of seeds in each case, which germinated. It struck me
that possibly either the Dutch bulb was too young or that it was not
sufficiently acclimatised to afford results either with its pollen or its
pistil ; for the climate, or the season, or the cultivation \c. may interfere
with a successful result.”
Mr. C. C. Hurst has given us the following important conclusion from
his own experiences: ‘‘ The nigro-hirsute section of Dendrobiums are
well known to be bad setters. Mr. R. Eichel, of Bradford, tells me that
for eight years he has failed to cross D. formoswmn with pollen of the
deciduous section ; but that he has now seedlings two and a half months
old of D. formosum x D. nobile (male) from four seed-pods. This
circumstance proves to us once more how misleading and unsatisfactory
purely negative results are, and in this there is much hope for the future.
However many times a cross has failed to set, we can never be sure that
it may not be accomplished by some one. Very trifling conditions seem
to affect the delicate and susceptible organs of reproduction, causing
apparent sterility. For instance, it is said that Hpidendrum ciliare can
only be fertilised with success in the evening, when the flowers begin to
emit their fragrant perfume; though this did not prove to be the case
with Mr. Veitch.”
One of the most unlikely results occurred with Poppies. M. Henry
L. de Vilmorin succeeded in raising a hybrid between Papaver bracteatum
and one of the double-flowered varieties of P. somniferum. The seedlings
were annuals, and bore single carmine-coloured flowers. At first the
plants were nearly all sterile; but subsequently seed was freely
produced.*
With regard to Ferns, Stelzner t describes the hybridisation of two
species of Gymmnogramma, viz. G. chrysophylla and G. lanata. One
plant so raised was so different from the parents that Koch named it
G. Stelzneriana. It proved to be entirely barren. But in 1864 he
repeated the experiment, and had a number of plants of the hybrid, all
oi which were wholly fertile.
M. Naudin experienced a similar result with Daturas : thus, “ D. levis,
ferox, Stramonium, and quercifolia, four species perfectly distinct, between
which there are no known intermediates, and moreover they do not
appear susceptible of variation. Nevertheless, though very distinct,
these species are sufficiently closely related to admit of reciprocal
impregnation, and to give rise to hybrids ; which, though sterile at first,
become very fertile at a more advanced period.”’ §
One cannot do better than conclude with the hopeful advice of Dean
Herbert, in alluding to the artificial separation of genera by botanists :
“Let the cultivator not be discouraged by every nominal generic
separation; but let him take his own view of apparent affinities, and
bring the accuracy of those separations to the test.’’ |
Gard. Chron. 1896, Jan. 11, p. 50.
Wochenschrift, Berlin, 1859.
Bull. Bot. Cong., Amsterdam, 1866.
§ “On Hybridism considered as a Cause of Variability in Vegetables,’’ Jovwn.
R.H.S. New Series, vol. i. p. 1.
|| Essay on Hybridisation amongst Vegetables.
Pitter
HYBRIDISATION AND ITS FAILURES. 89
DISCUSSION.
Tue VEN. ARCHDEACON MEREDITH: You said, Professor Henslow, that
the French Pelargonium would not hybridise with the English. Are
there any special characteristics by which the French Pelargonium
is known; or would any other Pelargonium hybridise with the
English ?
Proressor Henstow: The report was sent to me by one of the
numerous friends I have to thank for a variety of information. There
was no other remark on the subject, merely the statement of the fact.
ARCHDEACON MerepitH: I have tried it myself, but have generally
failed.
Proressor Henstow: Then that corroborates my informant.
ARCHDEACON MerrepitH: Are there any differences between Pelar-
goniums grown in other countries, such as Germany or America ?
Proressor Henstow: That I cannot tell you. I am passing on my
information just as I received it.
ARCHDEACON Merepitu: Is it possible for plants to get naturalised
to the particular country where they are reared? After a time do they
lose their foreign characteristics ?
Proressor Henstow: I think that is so. AsI have said the Primula,
according to Mr. Sutton, will not now cross with the original form from
which it is derived—the Chinese form. I do not know of any other
instance ; perhaps other cultivators may know.
Mr. Georce Bunyarp, V.M.H.: I would like to say that a gentleman
in our neighbourhood has made many curious crosses, among which is
one of the Gooseberry and the Blackcurrant. He succeeded in producing
fruit on it, and I tasted it; but it was of no use whatever from a com-
mercial point of view, and I did not entertain his offer to sell the plant
tome. He also had a cross between the Blackcurrant and Ribes san-
guinea, and between the Ribes sanguinea and the Gooseberry (p. 168).
Prorressor Henstow: Do you know whether the seed was retained ?
Mr. Bunyarp: Yes.
ProFressor Henstow: That is an advance on the information that
I possessed.
90 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
NOTES ON SOME EXPERIMENTS IN HYBRIDISATION AND
CROSS-BREEDING.
By Mr. C. CHAMBERLAIN Hurst, F.L.S.
Durine the past few years the question of inheritance has been of
increasing interest to students of Evolution as well as to the practical
breeder.
Since the foundation-stone of the subject was laid by Charles Darwin
in the standard work, ‘‘ Animals and Plants under Domestication,’’ our
knowledge of one part of it has considerably increased. Thanks to recent
improvements in the mechanism of the microscope, and the consequent
facilities for studying the inner processes of fertilisation, the tendency has
been for students of heredity to give most of their attention to the mys-
teries of the germ-cells and the part they play in sexual reproduction.
This is, undoubtedly, very desirable and very necessary ; yet, on the other
hand, there seems to be a danger that in so doing we may lose sight of
the broad facts of inheritance as manifested to us in the outward charac-
ters of plants and animals. And it seems to me that, notwithstanding
the great body of facts already brought together by Darwin in his magni-
ficent work, there is still a wide field open to the student in making
further experiments and in gathering fresh facts.
The aim of this paper is to record, as concisely as possible, some
experiments in the hybridisation and cross-breeding of plants, carried out
by myself and others, which seem to bear directly upon the problems
of inheritance and variation.
THe INHERITANCE OF VARIETAL CHARACTERS.
From the horticultural point of view, the inheritance or non-inherit-
ance of varietal characters is most important. If a useful or orna-
mental variety be capable of transmitting its good qualities to its
offspring, then its own natural value becomes greatly enhanced, and in
the course of a few generations a more or less permanent race may be
established. Most breeders have a strong impression that varieties
possess the power of transmitting their qualities to their offspring, and
in practice they take care to breed only from the best which suit their
purpose, in the hope that the improvement may be maintained, and, if
possible, increased. But, having observed many exceptions to that
general rule, in the Orchidee, I have thought it worth while to consider
the question somewhat in detail. Take, first of all, a natural variety
fertilised with its own pollen; in this case, if a varietal character be
hereditary at all, it should, @ priori, be especially so when fertilised with
its own pollen. Paphiopedilum Lawrenceanum Hyeanum is a colour
form of the type, in which all the purple and brown colouring matter is
suppressed, leaving the whole plant shades of green and white. Mr.
Norman Cookson, of Wylam-on-Tyne, fertilised this variety with its own
pollen, and a batch of seedlings was raised.
EXPERIMENTS IN HYBRIDISATION, &c. I
The first eight plants that flowered reproduced exactly the characters
of the parental variety, P. L. Hyeanum, but the ninth one reverted to an
ordinary form of the type P. Lawrenceanum. P. insigne Sander is a
variety in which nearly all the brown and green colouring matter of the
type has vanished, leaving the variety shades of yellow and white. Mr.
Fic. 9.—PAPHIOPEDILUM INSIGNE SANDERS. (Orchid Review.)
Norman Cookson has also raised this perfectly true from self-fertilised
seed. (Fig. 9.)
P. x Harrisiamum Rossianum is a striped variety or sport of a light-
coloured hybrid between P. villosum and P. barbatum, in which the
colours of the two parents, in the flowers, lie side by side, instead of being
fused together as in the type, giving the variety a curious harlequin
appearance. Mr. H. J. Ross, of Florence, fertilised this variety with its
92 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
own pollen, and the first plant which flowered reproduced the varietal
characters faithfully, while the second one reverted. to the light-coloured
original form.
Dendrobium nobile Cooksonianum is an abnormal variety, with the
petals coloured somewhat as in the lip (irregular peloria). This variety
was crossed by Mr. Cookson with D. n. nobilius, a variety with deep
purple sepals and petals; and from the same seed capsule were raised
both D. n. Cooksonianum and D. n. nobilius true to character, together
with a series of reversionary forms grading down to the ordinary type of |
D. nobile.
On the other hand, Mr. Fred Hardy, of Ashton-on-Mersey, crossed a
large form of the typical D. nobile with pollen of D. n. Cooksonianum,
and, though the seedlings resulting therefrom varied considerably, not one
had the characteristics of D. n. Cooksonianum.
Again. Mr. Cookson crossed D. n. Cooksonianum with pollen of D. n.
Burfordiense, the latter being a variety with the two lower sepals
coloured like the lip, instead of the petals, as in D. n. Cooksonianum. One
of these seedlings reproduced D. n. Burfordiense truly.
Mr. Cookson also crossed D. n. Burfordiense with a distinct species,
D. Findlayanum, and raised a hybrid known as D. x Cybele, Oakwood var.,
and all the plants reproduced the characteristic blotch on the lower sepals
asin D.n. Burfordiense. (Fig. 10.) Both D. n. Cooksonianum and D. n.
Burfordiense are technically anomalies, being cases of irregular peloria ;
and they seem to reproduce their sportive characters in their offspring
either wholly or not at all, there being no intermediate forms between
them and the normal.
D. x Cybele, Oakwood var., mentioned above, is a good illustration
of the inheritance of varietal characters, especially when we remember
that the typical D. nobile, crossed with D. Findlayanum, produces the
typical D. x Cybele ; and again, when D. n. nobilius, a richly coloured
variety of the type, is crossed with D. Findlayanum, the result is
D. x Cybele nobilius, a correspondingly coloured variety of the typical
hybrid.
D. nobile crossed with D. Falconeri produces the typical D. x Venus,
but when D. n. nobiliusis used as one parent D. x Venus magnificum
is produced, its colour being correspondingly deeper than the type.
D. nobile crossed with D. aureum gives the typical D. x
Ainsworthii ; but Messrs. Veitch & Sons, of Chelsea, by using
special varieties of each species as parents, produced D. x Ainsworthii
splendidissimum, a greatly improved form. On the other hand, a partial
exception may be quoted where D. n. nobilius, crossed with D. aureum,
produced D. x Ainsworthii Edithe, a light-coloured form of D. x Ains-
worthii splendidissimum, inheriting the form of D. n. nobilius, but not
the colour.
Mr. Cookson crossed the typical D. nobile with the typical D. x
Ainsworthii, and raised a light-coloured form called D. x Apollo.
Mr. J. Cypher, of Cheltenham, and Mr. C. Winn, of Birmingham,
crossed D. n. nobilius with D. x Ainsworthii splendidissimum, and raised
the correspondingly deep-coloured D. x Rubens; while the Hon. Oakes
Ames, of Massachusetts, raised an almost identical hybrid from the
EXPERIMENTS IN HYBRIDISATION, &c. 93
reverse cross; but, on the other hand, Mr. R. B. White, of Ardarroch,
raised a rosy-coloured form of D. x Rubens, nearer to the type, from the
same Cross.
Again Baron Schréder crossed D. n. Schréderianum, a variety with
white sepals and petals, with .D. x Ainsworthii splendidissimum, which
Fie. 10.—Denprosium x CyBELE, VAR. OAKWOODIENSE. (Gardeners’ Chronicle.)
(D. NopmLE BurrorpDIENSE x D. FINDLAYANUM.)
Showing the Inheritance of the Peloriate Sepals of D. n. Burfordiense.
produced D. x R. dellense, also with white sepals and petals, and Mr.
Cypher crossed D. n. pulcherrimum, also a variety with white sepals and
petals, with D. x Ainsworthii splendidissimum, which produced D. x R.
Apollo and D. x Apollo grandiflorum, both with white sepals and petals.
The original D. Wardianum from Assam, with slender pseudo-bulbs,
crossed with D. lituiflorum by Messrs. Veitch, gave D. x micans with
slender pseudo-bulbs, whereas the modern D. Wardianum from Burma,
94 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
with stout pseudo-bulbs, gives D. x micans with pseudo-bulbs corre-
spondingly stout. .
Varietal characters seem also to be generally inherited in the
Cypripedium group; for instance, Paphiopedilum insigne crossed
with P. Spicerianum produced the typical hybrid P. x Leeanum, with
Sir Trevor Lawrence ; but when P. i. Maulei or P. i. Chantini were used
as parents by Messrs. Veitch and Mr. Winn, P. x Leeanum superbum
was the result, the offspring in these cases corresponding with the parents’
varieties in having a larger area of pure white, and being much broader
in the upper sepal of the flower. Again, when the densely spotted P. i.
Wallacei was used as a parent by M. Jules Hye-Leysen, of Ghent, the
densely spotted P. x Leeanum Albertianum was the result; while the
yellow P. i. Sander gave with Messrs. Veitch the yellowish P. x Lee-
anum Prospero, and the large P. i. giganteum gave with Messrs. Heath, of
Cheltenham, the large P. x Leeanum giganteum. Finally, P. i.
Chantini crossed with P. Spicerianum roseum gave with Hon. Erastus
Corning, Albany, U.S§.A., the richly coloured P. x Leeanum roseum. In
the same way, the typical P. insigne crossed with P. villosum gives
P. x nitens Sallierii, while P. i. Chantini and P. i. Maulei give P. x
nitens, P. x n. superbum, P. x n. Celeus, and P. x n. giganteum; all
being superior forms, showing clearly the larger flowers, broader upper
sepal, and white area of the parent varieties. Similarly, the typical
P. insigne crossed with P. barbatum gives the typical P. x Ashburtoniz,
while the variety P. i. Chantini, with M. Bauer, of Paris, gave P. x A.
Barteti and P. x A. Laforcadei, both showing the varietal characters
of the parental variety. In the same way, the typical P. insigne, crossed
with P. Fairieanum, gave with Messrs. Veitch the typical P. x Arthur-
ianum ; but when their Mr. Seden used P. i. Chantini as the parent, the
result was P. x A. pulchellum, in which the characters of the parental
variety are marked. Again, the typical P. barbatum crossed with P.
bellatulum, with several raisers, has given the typical P. x Richmanii,
with nearly horizontal petals, while P. barbatum Crossii, with drooping
petals, when used as the parent in this cross, has given P. x R. Leysen-
ianum, P, x R. ‘‘ Francois Peeters,’ and P. x R. “ Lilian Greenwood,”’
all with pendent petals.
Two apparent exceptions to the above may be cited: P. b. Crossii
crossed with P. Charlesworthii gave P. x barbato-Charlesworthii, with
nearly horizontal petals, and P. b. Crossii crossed with P. Spicerianum
eave P. x Eyermannianum Hermione, with nearly horizontal petals.
P. Boxalli crossed with P. hirsutissimum with Mr. Cookson, gave the
typical P. x Godseffianum, but the dark-coloured variety P. B. atratum,
used by M. Desbois, gave the dark-coloured P. x G. Jupiter. In the
same way P. Boxalli crossed with P. Spicerianum, by Messrs. Veitch.
gave the typical P. x Calypso, while P. x B. atratum, used by Mr.
Winn and Mr. Cookson, gave the darker forms, P. x C. Winn’s var.,
P. x C. Armstrongianum, and P. x C. Oakwood var. Similarly P.
Boxalli, crossed with P. barbatum, gives P. x apiculatum, while P. B.
atratum gives P. x a. atratum.
In another section of the Cypripedium group the inheritance of varietal
characters still holds good to a large extent. For instance, Phragmi-
.)
2v1eU
>
v
(Orchid I
AGMIPEDILUM CAUDATUM WZALLISII.
>
‘
PHE
Fie. 11.
Showing normal Lip.
96 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
pedilum Schlimii crossed with P longifolium, with Messrs. Veitch, gave
the typical P. x Sedenii (the reciprocal cross, too, being exactly the same),
whereas P. Schlimiu albiflorum, with light-coloured flowers, gave P. x
Sedenii candidulum, with light-coloured flowers; while P. Schlimii,
crossed with P. longifolium Roezlii, with dark-coloured flowers, gave P.
< Sedenii porphyreum, with dark-coloured flowers. Similarly, P. longi-
folium crossed with P. caudatum gave the typical P. x grande, while
the darker variety, P. 1. Roezlii, gave the darker P. x grande
atratum.
One of the most distinct and interesting varieties in the Cypripedium
Fre. 12, PHRaGMIPpEDILUM * ScHRODERA. (Orchid Review.)
(P. caupATUM 9 x P. SEDENII 2.)
Hybrid from P. caudatum with the normal Lip of its Parent.
soup is Phragmipedilum caudatum Lindenii, a natural peloriate variety
so distinct that, when it was first introduced, Lindley created a new genus
for it. It is peculiar in being lipless, the place of this organ being
oceupied by a long petal-like segment which sometimes measures twenty
inches in length ; it has also a third fertile stamen inserted below the
stigma at the base of the column, This curious plant was first found
growing wild in Rep. Colombia, by the late M. Jean Linden, of Brussels,
in 1843, and has since been found by later collectors in other localities,
so that apparently it must breed true to character in its own habitat.
There is not much doubt, however, that it is simply a peloriate form of
Fro. 13.—Prnaomirepi.um x Harpyanum, var. Penenaus. (Journal of Horticulture.)
(P. x Aryswortni caLurnum 2 = P. cacparom Linpentt d.)
With normal Lip; the abnormal Lip of P. c. Lindenii not inherited.
(To face page 97.)
EXPERIMENTS IN HYBRIDISATION, &c. 97
P. caudatum, for a flower once appeared on a typical P. caudatum
midway between this curious variety and the type.* This curious
variety, P. c. Lindenii, is interesting from another point of view. In its
native home it apparently breeds true to character, yet when crossed
with other species its curious characters do not appear to be reproduced
at all. For instance, it has been crossed with P. longifoliam, giving P.
x grande macrochilum (fig.14); with P. x conchiferum, giving P. x Clonius;
with P. x Ainsworthii calurum, giving P. x Penelaus (fig, 13) ; and with
P. x grande, giving P. x macrochilum, and in no case has its
curious lipless character been transmitted. It would be interesting if
someone would fertilise this curious variety with its own pollen, or cross
it back again with one of the four hybrids of which it has been a parent,
and record the result.
Many more instances of inheritance and non-inheritance of varietal
characters in the Orchidew might be recorded, but space will not permit
any more. Suffice it to say that a general survey of the whole of the
facts has brought me to the following conclusions :—
(1) Distinct varieties tend to transmit their qualities, especially if
fertilised with their own pollen, though exceptions are not rare.
(2) The chief exceptions seem to arise where the parents or the
ancestors of the variety have been variable.
(8) Slight variations are seldom hereditary.
(4) Abnormal sports are generally transmitted wholly or not at all.
(5) Distinet varieties, as a general rule, transmit their qualities in
different degrees, sometimes wholly, sometimes partly, and at other times
not at all.
(6) Varietal characters can seldom be traced in the second or follow-
ing generations, unless they happen to recur on both sides of the
pedigree.
(7) The law of Partial Prepotency, elaborated further on in this
paper, may possibly account for these varied results in the inheritance
of varietal characters.
Tue INHERITANCE OF SPECIFIC CHARACTERS.
Those who have studied hybrids between distinct species must be
impressed with the undoubted inheritance of specific characters.
Varietal characters, while perhaps of more practical importance, are
yet so indefinable, so uncertain, and so fleeting that in the second
generation they are with difficulty traced at all. On the other hand,
specific characters are more definable, more certain, and more lasting,
and can be traced through several generations. For instance, in
Paphiopedilum x triumphans, a hybrid of the third generation raised by
M. Jules Hye-Leysen, of Ghent, the crimson veining in the upper sepal
of the flower can be traced through the parent, P. x enanthum superbum,
and the grandparent, P. x Harrisianum, back to the great-grandparent,
P. barbatum.
In studying the inheritance of specific characters, I have found it a
great advantage to take up a special group of plants and to study their
* See Dr. Maxwell Masters, in Veitch’s ‘‘ Manual of Orchids,” x. 1894, p. 45, figs. 6, 7.
H
‘poyoyUtl you muepury ‘0 ‘gq Jo diry [eusouqe oyy ‘ dry [wus1ou WAT AY
4
((\ PUNGaNIT “UvA ‘WALVaaVO ‘g x 4 WATTOSTONOT *g)
(apnudiyp ,sLauapany)
‘MO TIHOOUNVN “UVA ‘MONVUD x WOTICUdINOVYHY— FL “Ply
ae ( SWELCY Se
CGARDCHRON.
EXPERIMENTS IN HYBRIDISATION, &c. 99
characters as carefully and minutely as a monographer would do, and in
this way I have been able to follow the inheritance of specific characters
much more easily than otherwise I could have hoped to do. In following
out this idea I have chosen the orchideous genus Paphiopedilum (Pfitz),
better known in gardens as Cypripedium, partly because hybridisation
has been carried farther in this genus than in many others, and partly
because I have the good fortune to have a large collection of living
hybrids and their parents of this genus under my own observation from
day to day.
The limits of this paper will not allow fully detailed observations, but
a few condensed analyses of some primary hybrid Paphiopedilums will
well illustrate the inheritance of specific characters. In these cases
practically the whole plant has been analysed from living specimens,
twenty points in all being taken into consideration :—
(1) The habit of growth; (2) the habit of flowering ; the form or
shape of the (8) leaves, (4) scape, (5) bract, (6) ovary, (7) upper
sepal, (8) lower sepal, (9) petals, (10) lip or slipper, (11) staminode ;
the colour of the (12) leaves, (18) scape, (14) bract, (15) ovary,
(16) upper sepal, (17) lower sepal, (18) petals, (19) lip or slipper,
(20) staminode.
Each of these parts or organs of the hybrid has been compared with
the same part of each of the parent species. Each part is then classed
in relation to the two parents, either (a) in the ratio as 1:1, which re-
presents the part as fairly intermediate between the two parents; or (b)
in the ratio as 3:2, which represents one parent to be slightly pre-
dominant in that particular part; or (c) in the ratio as 2:1, showing the
decided prepotency of one parent in that part; or (d) in the ratio as 3: 1,
showing the very large prepotency of one parent in that part. In this
way the twenty parts are classified, and when the various figures are
added together one can see at a glance the total ratio of one parent to the
other in the hybrid. In the following condensed analyses I have ignored,
for the sake of simplicity, all the ratios as 1:1 and also those as 8: 2,
classing them as intermediate or thereabouts, and only showing the
undoubted prepotencies of either parent in the ratios as 2:1 and over.
At the end of each are given the full ratios of the plant as a whole, as
originally analysed, with the corresponding percentages of the predominant
parent, for the sake of comparison. (For additional instances, see also
under the heading of “ Variation of Primary Hybrids.’’)
(1) Paphiopedilum x Winnianwm, a hybrid raised by Messrs. Veitch,
of Chelsea, out of P. villosum (Pfitz) by P. Druryi (Pfitz). In form, the
parent P. Druryi is prepotent in habit of growth, leaves, scape, and lower
sepal; while P. villosum predominates in habit of flowering, petals, and
staminode ; in all, favouring P. Druryi as 18:17. Jn colowr, P. Druryi
preponderates in the leaves, lower sepal, and staminode ; while P. villosum
prevails in the petals ; altogether favouring P. Druryi as 16:15. The
whole plant in form and colour favouring P. Druryi as 34: 32, or
51°5 per cent.
(2) P. x Swinburnet, a hybrid raised by Messrs. Heath, of Cheltenham,
out of P. insigne (Pfitz) by P. Argus (Pfitz). In form, the parent P.
insigne is prepotent in bract, ovary, and upper sepal; while P. Argus
H 2
100 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
predominates in the lip; in all, favouring P. insigne as 24:23. In
colour, P. Argus predominates in lower sepal, petals, and lip, altogether
favouring that parent as 19:15. The whole plant, in form and colour
favouring P. Argus as 42:39, or 51°8 per cent. (Fig. 16.)
(8) P. x Ceres Medea, a hybrid between P. Spicerianum (Pfitz) and
P. hirsutissimum (Pfitz), raised by Mr. Latham, of Birmingham. Jn
form, the parent P. Spicerianum is prepotent in the upper sepal, while
P. hirsutissimum predominates in the leaves, ovary, and staminode; in
all, favouring P. hirsutissimum as 20:19. Jn colour, P. Spicerianum
preponderates in the leaves, bract, upper sepal, and staminode ; while
P. hirsutissimum prevails in the scape and petals, altogether favouring
P. hirsutissimum as 16:15. The whole plant, in form and colour, favour-
ing P. hirsutissimum as 36: 34, or 51°4 per cent. (Fig. 17.)
(4) P. x Arthurianum, a hybrid out of P. Fairieanum (Pfitz) by
Fie. 15.—P.x SeLuicerum. Fic. 16.—P.x Swinsurner. Fic. 17.—P. x CERES MEDEA.
Hysrip PAPHIOPEDILUMS.
P. insigne (Pfitz), raised by Messrs. Veitch. Jn form, the parent P. insigne
is prepotent in the upper sepal, while P. Fairieanum predominates in the
lip and staminode ; in all, favouring P. Fairieanum as 23:20. In colour,
P. insigne preponderates in the scape and upper sepal, while P. Fairie-
anum prevails in the staminode ; altogether, intermediate, as 16:16.
The whole plant, in form and colour, favouring P. Fairieanum as 39 : 36,
or 52 per cent.
(5) P. x conco-villosum, a hybrid between P. concolor (Pfitz) and
P. villosum (Pfitz), raised by Messrs. Charlesworth, of Bradford. Jn
form, the parent P. concolor is prepotent in the leaves and lip, while
P. villosum predominates in bract and ovary; in all, favouring P. villosum
as 23:22. In colour, P. concolor preponderates in the lower sepal and lip,
while P. villosum prevails in the leaves and bract; altogether favouring
P. concolor as 15:12. The whole plant, in form and colour, favouring
P. concolor as 87 : 85, or 51°38 per cent. j
EXPERIMENTS IN HYBRIDISATION, &c. 101
(6) P. x Ashburtome Laforcadei, a hybrid raised by M. Bauer, of
Paris, out of P. barbatum by P. insigne Chantini. Jn form, the parent
P. barbatum is prepotent in habit of growth, leaves, lip, and staminode ;
while P. insigne preponderates in the lower sepal and petals; in all,
favouring P. barbatum as 20:18. Jn colowr, P. insigne predominates in
the lower sepal. Altogether the hybrid is fairly intermediate, as 15:15.
The whole plant, in form and colour, favouring P. barbatum as 35 : 38
or 51:4 per cent. (Fig. 20.)
(7) PB. x apiculatum, a hybrid raised by Mr. D. V. Drewett, of Riding-
Mill-on-Tyne, out of P. barbatum (Pfitz) by P. Boxalli (Pfitz). In form,
the parent P. barbatum is prepotent in habit of growth, leaves, and
staminode, while P. Boxalli predominates in the petals; in all, favouring
’
Fie. 18. Fie. 19. Fie. 20.
P. x APICULATUM. P. x LarHamianum I. P. x Asus. LAFORCADEI.
Fie. 21. Fig. 22. Hic, 23:
P. Boxaut. P. x RUBESCENS. P. INSIGNE MACULATUM.
PAPHIOPEDILUMS.
P. barbatum as 26:21. In colowr, P. Boxalli preponderates in the bract,
petals, and lip, while P. barbatum prevails in the staminode; altogether
favouring P. Boxallias 19:15. The whole plant, in form and colour,
favouring P. barbatum as 41: 40, or 50°6 per cent. (Fig. 18.)
(8) P. x selugerwm, a hybrid out of P. barbatum (Pfitz) by P. philip-
pinense (Pfitz), raised by Messrs. Veitch. Jn form, the parent P. barbatum
is prepotent in the leaves, while P. philippinense predominates in habit
of flowering, ovary, and lower sepal; in all, favouring P. philippinense as
20:19. In colowr, P. barbatum preponderates in the lip, while P. philip-
pinense prevails in the leaves and lower sepal; altogether fairly inter-
mediate, as 16:16. The whole plant, in form and colour, favouring
P. philippinense as 36:35, or 50°8 per cent. (Fig. 15).
102 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
(9) P. x Doncasterianum II., a hybrid between P. hirsutissimum
(Pfitz) and P. callosum (Pfitz), raised by Messrs. Charlesworth. In ferm,
the parent P. callosum is prepotent in habit of flowers, scape, bract,
ovary, lower sepal, and staminode, while P. hirsutissimum predominates
in the leaves and lip; in all, favouring P. callosum as 24:20. In colour,
P. callosum preponderates in scape, ovary, lower sepal, lip and staminode,
while P. hirsutissimum prevails in leaves, bract, and petals ; altogether
fairly intermediate, as 15:15. The whole plant, in form and colour,
favouring P. callosum as 39: 35, or 52°7 per cent.
(10) P. x Quies II., a hybrid between P. Curtisii and P. Hookere
volonteanum, raised by Messrs. Charlesworth. In form, the parent
P. Hooker is prepotent in habit of flowering, scape, and lip, while
P. Curtisii predominates in habit of growth, bract, ovary, and petals; in
all, fairly intermediate, as 19:19. In colowr, P. Hooker preponderates
Via. 24. Fie. 25.
Ep1-La:uiA x RADICO-PURPURATA. EPIDENDRUM RADICANS.
(Orchid Review.)
Generic Hybrid with its prepotent Pollen Parent.
in the ovary and upper sepal, while P. Curtisii prevails in the bract ;
altogether favouring P. Hookere as 17:16. The whole plant, in form
and colour, favouring P. Hookere, as 36:35, or 50°7 per cent.
From the above analyses it will be seen that in primary hybrids
between two species the amount of the inheritance of the specific charac-
ters of each parent is found to be about one-half.
THe INHERITANCE OF GENERIC CHARACTERS.
Generic hybrids, or bigeners, 7.e. hybrids between species belonging to
two distinct genera, have now become rather numerous, especially in the
Orchidex, in that order numbering about 150 distinct crosses. As a
rule it is found that generic characters, like specific characters, are
inherited in primary hybrids to the amount of one-half or thereabouts.
EXPERIMENTS IN HYBRIDISATION, &c. 103
An interesting illustration of this may be seen in the structure of the
pollinia in the many hybrids between Cattleya and Lelia.
The genus Cattleya (Lindl.) has four pollinia of equal size, arranged
in one row, while Lelia (Lindl.) has eight pollinia of equal size, arranged
in two rows of four each, being generally somewhat smaller than those of
Cattleya.
The hybrid genus Lelio-Cattleya x (Rolfe), obtained by crossing these
two genera, has eight pollinia, arranged in two rows of four each, as in
the parent Lelia; but in the lower row the pollinia are large and of
equal size, as in the parent Cattleya, while in the upper row they are
small, uneven, and apparently rudimentary. In this way the generic
characters of both parents are inherited.
Generic characters appear to be more powerful and more lasting than
either specific or varietal characters, persisting, little changed, for several
generations, possibly more; and would, no doubt, be much more difficult
to breed out than either specific or varietal characters.
For example, Lelio-Cattleya x leucoglossa, raised by Messrs. Veitch,
is a hybrid of the third generation, whose pedigree may be seen at a
glance in the following diagram :—
DIAGRAM SHOWING THE TWO PARENTS, FOUR GRANDPARENTS, AND EIGHT GREAT-
GRANDPARENTS OF Lamnio-CATTLEYA x LEUCOGLOSSA.
; ; | Cat- | ae
G2 % pas Cc 8 86. C. : B12 | tleya Lelia
Ee oe ie Min a Be 15% Mossiz | crispa
Gb es Boling @ = & (Hook.) ope
eit Dea Lie 24 eV, it ade tee ann. 1 ie arity: {
C | Lelio-Cattleya
; | x exoniensis
ie L. Ti. | (Veitch)
9 g gr lL ps rv
:
Cattleya Lelio-Cattleya
Loddigesii x fausta
(Lindl.) (Veitch)
Q 3
L21io-CarrLeya x LEUcoGLossA (Veitch).
According to Mr. Galton’s law of ancestral heredity, this hybrid
should contain in its pedigree } C. Loddigesii + } L.-C. x fausia
+ % C. Loddigesii + ~, L.-C. x exoniensis + =, C. Mossie
+ z L. ecrispa; or, to reduce it to more simple terms, ? C. Loddi-
gesii + $ C. Mossie + 3} L. crispa; that is to say, 3 Cattleya
+ ¢ Lelia. Yet, when we come to examine the generic characters of
104 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
this complex hybrid, we find that it is a pure Lelio-Cattleya, having
eight pollinia in two rows of four each, the upper row being small and
apparently rudimentary; and although the Lelia parentage is only
represented to the extent of 3, yet the generic characters are the same as
if it had been}. In other words, through its parent and grandparent
the hybrid has inherited the generic characters of one of its great-grand-
parents, while the specific characters of that ancestor can be traced but
little, and the varietal characters not at all.
Generic hybrids in the Orchidexw have produced many anomalies; for
instance, when the species of Lelia, Cattleya, and Sophronitis are
intercrossed, normal hybrids are produced, intermediate in their generic
characters; but when species of Lelia, Cattleya, and Sophronitis are
crossed with the reed-like species of Epidendrum, the latter genus is
always prepotent to a remarkable extent, completely swamping the other
genera, no matter how they may have been crossed; yet, in every case,
in specific and varietal characters, one can easily trace the influence of
the other parents, thus proving that the cross has been really and truly
made.
Seven positive cases, and no negative ones, of these prepotent Epi-
dendrum crosses are on record, and all agree in this curious generic
prepotency.
(1) Epiphronitis x Veitchii, raised by Messrs. Veitch out of Sophronitis
grandiflora (Lindl.) by Epidendrum radicans (Pay.).
(2) Epi-Cattleya x matutina, raised by Messrs. Veitch out of Cattleya
Bowringiana (Veitch), by Epidendrum radicans.
(8) Epi-Leelia x radico-purpurata, raised both by Messrs. Veitch and
Messrs. Charlesworth out of Lelia purpurata (Lindl.), by Epidendrum
radicans. (Figs. 24 and 25.)
(4) Epi-Lelia x Charlesworthii, raised by Messrs. Charlesworth out of
Lelia cinnabarina (Lindl.), by Epidendrum radicans.
(5) Epi-Cattleya x‘ Mrs. James O’Brien,’ raised by Messrs. Veitch out
of Cattleya Bowringiana, by Epidendrum x O’Brienianum (Veitch), the
latter parent being itself a hybrid out of EH. evectum (Hook. f.), by
K. radicans.
(6) Epi-Lelia x heatonensis (Charlesworth), out of Lelia cinnabarina,
by Epidendrum x O’Brienianum.
It is difficult to account for this anomaly, but I have suggested in
another place that possibly the aristocratic Cattleya and Lelia, as well as
the more modest Sophronitis, are all descended—or should it not be
ascended ?—from a lowly reed-like Epidendrum ancestor, and, when
crossed with their poor relations, tend to revert to their common ancestor.
In addition to these Epidendrum hybrids there are eleven curious crosses
between very distinct genera, which, strangely enough, have all reproduced
the characters of their seed-parents almost exactly.
(1) Zygopetalum Mackayi ¢ crossed with Odontoglossum nobile
(Pescatorei) ¢, both by Messrs. Veitch, of Chelsea, and by Messrs. Heath,
of Cheltenham, produced over 300 plants, of which more than twenty
flowered Z. Mackayi pure and simple (the remainder were thrown away
unflowered, but all were evidently the same species).
(2) Zygopetalum Mackayi 2 crossed with Odontoglossum crispum ¢.
EXPERIMENTS IN HYBRIDISATION, &c. 105
(3) Z. Mackayi 9 crossed with O. grande ¢.
(4) Z. Mackayi ? crossed with O. bictonense ¢.
(5) Z. Mackayi ? crossed with Lycaste Skinnerii, all by Messrs.
Veitch, produced a few seedlings of each cross, all of which flowered
pure Z. Mackayi.
(6) Z. Mackayi ¢@ crossed with Oncidium unguiculatum ¢, by Rev.
F. D. Horner, of Burton-in-Lonsdale, and by a Florentine hybridist,
both produced Z. Mackayi, pure and simple, four plants being raised.
(7) Epidendrum x O’Brienianum ¢ crossed with Dendrobium crystal-
linum 2, by Mr. Statter, of Stand Hall, near Manchester, produced a
large number of plants, all of which flowered EK. x O’Brienianum.
(8) Phragmipedilum longifolium Hartwegii 2 crossed with Paphio-
pedilum Stonei ¢, by Mr. R. M. Grey, for Mr. Graves, of Orange, Mass.,
produced a plant which flowered Phrag. longifolium Hartwegii.
(9) Phrag. x Sedenii ¢ crossed with Paph. Stonei ¢, by Mr. Statter,
produced a plant which flowered Phrag. x Sedenii (as far as one could
determine from a somewhat imperfect first flower). I also have an un-
flowered plant of the same cross, which is undoubtedly a Phragmipedilum
in its habit of growth, and form and colour of leaves.
(10) Lelia harpophylla @ crossed (curiously enough) with Paphio-
pedilum villosum ¢ (belonging to a distinct swb-order) and the reverse
cross, viz.—
(11) Paph. villosum ¢? x Lelia harpophylla 3, both raised by a well-
known expert hybridist in the North of England, have produced plants,
yet unflowered, which I have seen and examined, and which, in each case,
have the habit and characteristics of their respective seed-parents, No. 10
being evidently true Lelia and No. 11 true Paphiopedilum.
Here we have eleven distinct crosses between nine very distinct
genera, all of which have produced “false hybrids,” reproducing the
characters of their seed-parents absolutely unmodified by the so-called
pollen-parents. Nor are these mere solitary exceptions, for as far as
experiments have yet been made they seem to be the absolute rule
with no exception ; in one case, as we have seen, no less than 300 plants
were raised from one capsule, all with the same result. These curious
crosses are evidently very different from the prepotent Epidendrum
hybrids, for in the latter it was the pollen-parent that was prepotent,
and all of them were slightly modified by the influence of the other
parent, showing them to be true hybrids. But those now under con-
sideration are evidently not true hybrids at all, showing no trace of one
of the so-called parents.
In the face of modern knowledge concerning the germ-cells and the
inner processes of reproduction, it would be idle for us to assert that the
seeds which produced these plants had ever been hybridised. They must
‘therefore have been fertilised with their own pollen, or have reproduced
themselves by parthenogenesis. After a lengthy correspondence and a
careful sifting of the facts, I have come to the conclusion that in eight
cases at least out of the eleven, self-fertilisation is quite out of the
question, being practically impossible in the circumstances.* There
* See Jour. Roy. Hort. Soc. xxi. 1898, p. 477.
106 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
seems to remain to us then one reasonable explanation, and that is
parthenogenesis. :
Parthenogenesis, or the production of fertile seeds in a capsule without
fertilisation, is well known to occur in certain plants, e.g. Gnapha-
lium, Mercurialis, and Ceelebogyne.*
Professor Henslow, in his ‘“‘ Structure of Flowers,’’ p. 171, relates how
Dr. Treub found a larva of an insect in the ovary of a Mauritian Orchid,
Liparis latifolia, which seemed to feed on the juices secreted therein,
without injuring either the ovules or the ovary. In a short time, without
the aid of pollen, the ovules developed and became covered with seed-
coats, as if under the influence of pollination; the irritation of the larva
seemed to have developed the ovules in the same way the pollen
tubes would have done. And this is possibly what has happened with
these curious crosses. The pollen tubes of the distinct genera may have
irritated and developed the ovules by feeding on the juices secreted by
the ovary, yet by some incompatibility failed to fertilise the egg-cells, the
result being seed-buds developed within the capsule, naturally bearing
the characters of the seed-parent only. [Whether these seed-buds arise
direct from the egg-cells, or from the antipodal cells as in cases of poly-
embryony in Fuchsia, Allium, and Citrus, yet remains to be seen. T]
There is, however, one slight difficulty in this explanation which
puzzled me for some time, and that is that hitherto it was generally
understood that in parthenogenesis all the plants were exactly
alike from one capsule, reproducing the varietal characters of the seed-
parent down to the minutest detail, just in the same way as ordinary buds
and cuttings do; whereas, in the case of the Zygopetalum crosses par-
ticularly, the seedlings varied slightly in colour, form, and size, both
iter se, and from the seed-parent also.
But recent experiments with “Daphnia” have shown that there is
a certain amount of variation even in parthenogenetic offspring {; and as
it has been already demonstrated that at least one nuclear division occurs
in parthenogenesis,§ this might reasonably have been expected. The one
slight difficulty, therefore, in accepting parthenogenesis as the explanation
of the above curious crosses seems now to be removed.
THE VARIATION OF PRimMARY Hyprips.
Hybrids of the first generation between the same pair of species are
found to have a certain specific likeness, yet at the same time they differ
one from the other in varietal characters.
Sex, per se, does not seem to have any influence in the variation of
hybrids in the Orchidew (owing possibly to their being hermaphrodite by
nature), the same varieties occurring both in the reverse and obverse
crosses ; indeed, in several cases recorded, the progeny of the reverse
cross and that of the original one have proved to be exactly the same.
As we have seen in the inheritance of varietal characters, when a different
variety is used as a parent, the result tends to be different, the variation
generally corresponding with that of the variety used. But the variation
* Kerner & Oliver, “ Nat. Hist. Plts.’’ ii. p. 469.
+ N. H. P. ii. p. 469.
t Roy. Soe., 4/5/99, “ Nature,’’ 59, p. 142,
§ Weismann’s “ Germ Plasm,” 1893, p. 347.
EXPERIMENTS IN HYBRIDISATION, &c. 107
of first hybrids extends beyond the differences caused by using different
varieties as parents, because we often get considerable variation among
hybrids raised from the same seed-capsule.
How then is this variation to be explained? A careful analysis of
hybrids of Paphiopedilum seems to give a clue to this problem, as the
following condensed analyses show. (Compare also those given under
the heading of “‘ The Inheritance of Specific Characters.’’)
(1) (a) Paphiopedilum x Lathanianum I.—A hybrid between P..
Spicerianum (Pfitz) and P. villosum (Pfitz), first raised by Mr. Latham,
of Birmingham. Jn form, the parent P. Spicerianum is prepotent in the-
lower sepal and lip, while P. villosum predominates in the leaves ; in all,.
favouring P. Spicerianum as 20:15. Jn colour, P. Spicerianum prepon-
derates in the bract and upper sepal, while P. villosum prevails in the-
scape and lip; altogether favouring P. Spicerianum as 18:17. The-
Fie. 26. Mages PIT (E Fic. 28.
P. SprceRIANUM. P. x LatHamianum II. P. vILLOsuUM.
Primary Hybrid with its two Parent Species.
whole hybrid, in form and colour, favouring P. Spicerianum as 38 : 382,.
or 54°2 per cent. (Fig. 19.)
(1) (0) P. x Lathamianum II.—Another variety of the same parent-
age. In form, the parent P. Spicerianum is prepotent in the leaves,
lower sepal, and lip; in all favouring that parent as 23:17. In colour,
P. Spicerianum predominates in the upper sepal and staminode, while
the other parent, P. villosum, preponderates in the scape and petals.
altogether favouring P. villosum as 17:15. The whole plant, in form
and colour, favouring P. Spicerianum as 38: 34, or 52°7 per cent.
(Fig. 27.)
(1) (c) P. x Lathamianum ITI.—A third variety of the same parent-
age. In form, P. Spicerianum is prepotent in the scape, while P.
villosum predominates in the habit of growth, ovary, lower sepal, and lip ;
in all favouring P. villosum as 21:18. Jn colour, P. Spicerianum pre-
108 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
ponderates in the scape, bract, upper sepal, and staminode ; while C. villo-
sum prevails in the ovary, petals, and lip; altogether fairly intermediate,
as 15:15. The whole plant, in form and colour, favouring P. villosum
as 36 : 38, or 5271 per cent.
(2) (a) P. x Harrisianwm I.—A hybrid between P. villosum (Pfitz)
and P. barbatum (Pfitz) first raised by Messrs. Veitch. Jn form, the parent
P. villosum is prepotent in the habit of growth and leaves, while P. bar-
batum predominates in the staminode; in all, fairly intermediate, as
ee
ie ee
ie ast
+
me
ae
oi
*
e
+
Fic. 29.—PapHIoPEDILUM x LEEANUM SUPERBUM.
(P. insigne Chantinii x P. Spicerianum.)
16:16. In colour, P. villosum preponderates in the upper sepal, while
P. barbatum prevails in the leaves, bract, and staminode; altogether
favouring P. barbatum as 16:13. The whole plant, in form and colour,
favouring P. villosum as 82 : 29, or 52°4 per cent.
(2) (b) P. x Harrisianum II.—Another variety of the same parent-
age. In form, P. villosum is prepotent in the habit of growth, while P.
barbatum predominates in leaves and staminode ; in all, favouring P.
barbatum as 17:16. Jn colour, P. barbatum prevails in the leaves,
EXPERIMENTS IN HYBRIDISATION, &c. 109
altogether being fairly intermediate, as 15 : 15. The whole plant, in form
and colour, favouring P. barbatum as 382 : 31, or 50°7 per cent.
(2) (c) P. x Harrisianum III.—A third variety of the same parent-
age. In form, P. barbatum is prepotent in the habit of growth, leaves,
and staminode ; in all, favouring that parent as 19:16. Jn colour, P.
barbatum predominates in the leaves, bract, upper sepal, and staminode;
altogether favouring that parent as 17:12. The whole plant, in form
and colour, favouring P. barbatum as 36 : 28, or 56:2 per cent.
(3) (a) P. x Leeanuwm gigantewm.—A hybrid out of P. Spicerianum
(Pfitz) by P. insigne (Pfitz), var. giganteum, raised by Messrs. Heath, of
Cheltenham. In form, the parent P. Spicerianum is prepotent in the
leaves and upper sepal, while P. insigne predominates in the petals ; in all,
airly intermediate as 17:17. Jncolour, P. Spicerianum preponderates
Fra. 30. Fre. 31. Fie. 32%
P. INSIGNE CHANTINIL. P. x niTENS I. P. VILLOsUM.
Primary Hybrid with its two Parent Species.
in the upper sepal and petals, altogether favouring that parent as 18 : 15.
The whole plant, in form and colour, favouring P. Spicerianum as 35 : 32,
or 52°2 per cent.
(3) (b) P. x Leeanum superbum.—A hybrid of the same specific parent-
age, raised by Mr. Chas. Winn, of Birmingham ; but in this case P. insigne
Chantinii was the parental variety. In form, P. Spicerianum is pre-
potent in the upper sepal, lower sepal, and petals, while P. insigne pre-
dominates in the habit of growth, leaves, lip, and staminode ; in all,
favouring P. insigne as 22:17. In colour, P. Spicerianum preponde-
rates in the upper sepal, while P. insigne prevails in the lower sepal and
staminode ; altogether favouring P. Spicerianum as 17:16. The whole
plant, in form and colour, favouring P. insigne as 38 : 34, or 52°7 per cent.
(Fig. 29.)
(3) (c) P.x Leeanwm Albertianum.—A hybrid of the same specific
110 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
parentage, raised by M. Jules Hye-Leysen, of Ghent, the parental variety
used being P. insigne Wallacei. Jn form, P. Spieerianum is prepctent
in the habit of growth ; in all, favouring that parent as 24 : 23. In colour,
P. Spicerianum predominates in the leaves, while P. insigne preponde-
rates in the lower sepal and lip ; altogether favouring P. insigne as 17 : 16.
The whole plant, in form and colour, being fairly intermediate, as 40 : 40,
or 50 per cent. of each parent.
(4) (a) P. x nitens I.—A hybrid out of P. villosum (Pfitz) by P. insigne
(Pfitz), var. Maulei, raised by Messrs. Veitch. Jn form, the parent P.
insigne is prepotent in the ovary and lip; in all, favouring that parent as
23:19. In colowr, P. insigne predominates in the upper sepal, lower
sepal, and staminode, while P. villosum preponderates in the leaves ; alto-
gether favouring P. insigne as 18:14. The whole plant, in form and colour,
favouring P. insigne as 42 : 32, or 56°7 per cent. (Fig. 31.)
(4) (0) PB. x nitens IJ.—A second variety of the same parentage, received
by me from Mr. Winn, of Birmingham. Jn form, P. insigne is pre-
potent in the ovary and lip; in all, favouring that parent as 23:19. In
colour, P. insigne predominates in the upper sepal, lower sepal, and
staminode ; altogether favouring that parent as18:12. The whole plant,
in form and colour, favouring P. insigne as 41 : 31, or 56°9 per cent.
(4) (c) P. x nitens III.—A third variety of the same parentage, received
by me from Mr. Reginald Young, of Liverpool, and known as var. gigan-
tewum. In form, P. imsigne is prepotent in the ovary and upper sepal,
while P. villosum predominates in the habit of growth and leaves; in all,
favouring P. villosum as 20:19. Jn colour, P. insigne predominates in
the upper sepal and lower sepal, while P. villosum prevails in the ovary ;
altogether favouring P. insigne as 16: 12. The whole plant, in form and
colour, favouring P. insigne as 35 : 32, or 522 per cent.
(4) (d) P. x nitens IV.—A fourth variety of the same parentage, raised
by Messrs. Veitch, and known generally as var. superbum. In form, P.
insigne is prepotent in habit of growth, ovary, and upper sepal; in all,
favouring that parent as 25:18. Jn colowr, P. insigne predominates in
the leaves, upper sepal, and staminode; altogether favouring that parent
as 19:13. The whole plant, in form and colour, favouring P. insigne as
44 : 31, or 58°6 per cent.
(4) (e) BP. x mittens Sallierti, really the typical hybrid from
typical forms of both parents, and received by me from Mr. Reginald
Young, of Liverpool. Jn form, P. villosum is prepotent in the petals ;
in all, favouring that parent as 22: 20. In colowr, P. insigne predomi-
nates in the leaves, upper sepal, and lower sepal, while P. villosum pre-
ponderates in the petals; altogether favouring P. insigne as 19: 15. The
whole plant, in form and colour, favouring P. insigne as 39 : 37, or 51:3
per cent.
These hybrids, as a whole, are fairly intermediate between their two
parents, yet there is in most cases a local predominance of one parent or
the other in one part or another of the hybrid. This applies equally
either to form or colour.
When several hybrids from the same pair of species are compared
together, this variation of the parts, or “ Partial Prepotency,” as I propose
to call it, becomes even more apparent and more diverse. For example, in
EXPERIMENTS IN HYBRIDISATION, &c. 111
three hybrids raised from the same parents, in the first, the pollen-parent
may predominate in form in a certain part; in the second, the seed-
parent may prevail in that part; while in the third, that part may be
fairly intermediate between both parents ; while in regard to colour, these
conditions may be exactly reversed. But this only includes one part of
the hybrid, and the same law applies equally to every one of the parts;
so that when the changes are rung on twenty or more different parts by
the two parents, in both form and colour, we can well understand the
many possibilities of variation in hybrids of the same parentage; and I
venture to suggest that this law of Partial Prepotency, founded on actual
facts observed in hybrids of Paphiopedilum, may perhaps throw some
light on the question of variation in offspring of the same parents. Yet,
notwithstanding this variation in the parts, it is a remarkable fact that in
primary hybrids the whole plant taken together is fairly intermediate
between the two parents, the balance of power being well maintained in
the whole.
The greatest extreme observed by me, out of many cases in
Paphiopedilum, has been 58°6 per cent. of one parent, against 42-4 per
cent. of the other, the great majority being approximately 50 per cent.
of each parent. This hardly coincides with the popular belief that some
hybrids resemble one parent, while others resemble the other; but this
may be due simply to superficial observation, for where conspicuous parts
lean towards one parent, the casual observer might easily be deceived,
not noticing the inconspicuous parts which compensate for this by leaning
towards the other parent.
THE VARIATION OF SECONDARY HyBribs.
Hybrids of the second generation, whether of two, three, or four
species, differ notably from hybrids of the first generation of two species
by reason of their much wider range of variation. Whether this be due
simply to the increased factors in their pedigree, or whether apart from
that, I have not yet been able to gather sufficient evidence to determine ;
still, the fact remains that, from whatever cause, hybrids of the second
generation are far more variable than those of the first generation. As |
an illustration of this I will take two sets of hybrids in Paphiopedilum,
in one of which we will consider the colour of the flowers, and in the
other the habit, form, and colour of the leaves. Both groups are hybrids
of the second generation, from three distinct species (7.e. a hybrid of two
species crossed with a third species), and in both the law of Partial Pre-
potency is remarkably evident. The first of the two sets was raised by
M. Jules Hye-Leysen, of Ghent, between varieties of P. Spicerianum
(Pfitz) and P. x nitens, the latter parent being itself a hybrid between
P. insigne (Pfitz) and P. villosum (Pfitz). Some twenty-two hybrids
have already flowered, many of them having been raised out of the same
seed-capsule. Each of these hybrids has received a distinct name, and
perhaps worthily so, from their wide variation and distinctness ; but for
the sake of convenience I will allude to them as varieties of the original
one, viz. P. x aureum. The following diagram will show their pedigree
at a glance :—
112 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
DIAGRAM SHOWING THE Two Parents AND Four GRANDPARENTS OF
PAPHIOPEDILUM xX AUREUM (vars.).”
Pp Ne: pe esp
S. S. insigne | villosum
1P 1B
Spicerianum x nitens
PAPHIOPEDILUM xX AUREUM (vars.).
According to the Galtonian law of Ancestral Heredity, these varieties
should, on the average, show 4 P. Spicerianum + } P. x nitens + }
P. insigne++} P. villosum ; or to put it more simply, 3 P. Spicerianum + +
P. insigne + + P. villosum.
The following facts will show how, in regard to the colours of the
different parts of the flowers, the Galtonian law seems to be disturbed by
Partial Prepotency :—
Colour of Flowers (comprising Upper Sepal, Lower Sepal, Petals,
Lip, and Staminode).
(1) P. x aureum.—The parent P. Spicerianum is prepotent in the
staminode, while the grandparent P. insigne predominates in the upper
and lower sepals.
(2) P. x a. Hebe.—The parent P. Spicerianum and the grandparent
P. insigne together predominate in all parts of the flower, viz. upper
sepal, lower sepal, petals, lip, and staminode ; indeed this variety might,
at first sight, pass as a form of P. x Leeanum (P. Spicerianum x P.
insigne), buta careful examination reveals the influence of P. villosum,
especially in the shape and general habit of the flower.
(8) P. x a. Surprise.—The whole flower in colour resembles a
greenish form of P. insigne Sander, the spots of P. imsigne and the
ruby band of P. Spicerianum being quite obliterated in the upper sepal ;
yet, in form and a few minor details, its full parentage may be traced.
(4) P. x a. virginalis.—The parent P. Spicerianum predominates
in the upper sepal and staminode, while P. villosum preponderates in
the petals and lip. This variety would almost pass for a compact form
of P. x Lathamianum (P. Spicerianum x P. villosum), but differs again
in minor details, confirming its parentage.
(5) P. x a. Augusta.—The parent P. Spicerianum and the grand-
parent P. insigne together predominate in the upper sepal, while
P. Spicerianum alone preponderates in the staminode.
(6) P. x a. Eteocle——The parent P. Spicerianum predominates in
the upper sepal, the grandparent P. villosum in the petals, while P.
Spicerianum and P. insigne together preponderate in the staminode.
(7) P. x a. Hermione.—The parent P. Spicerianum predominates
in the upper sepal, P. insigne and P. villosum together preponderate in the
petals, while P. Spicerianum and P. insigne prevail in the staminode.
(8) P. x a. Hermode.—The parent P. Spicerianum and the grand-
EXPERIMENTS IN HYBRIDISATION, &c. i is i
parent P. insigne together predominate in the upper sepal, lower sepal,
and staminode. .
(9) P..x a. Hero.—P. Spicerianum and P. insigne together pre-
dominate in the upper sepal and staminode ; while P. Spicerianum and
P. villosum preponderate in the petals.
(10) P. x a. Minos.—P. Spicerianum and P. insigne together pre-
dominate in the staminode, P. insigne alone preponderates in the
upper and lower sepals, and P. villosum alone in the petals.
(11) P. x a. Gidipe.—P. Spicerianum and P. insigne together pre-
dominate in the upper sepal and staminode, while P. villosum alone
prevails in the petals.
(12) P. x a. Olympia.—P. Spicerianum and P. insigne together pre-
dominate in the upper sepal and staminode, while P. insigne alone
prevails in the petals.
(13) P. x a. Osiris —P. Spicerianum predominates in the upper
and lower sepals; P. villosum alone preponderates in the petals, and
P. insigne alone in the staminode.
(14) P. x a. Polynice.—P. Spicerianum and P. insigne together
_ predominate in the upper sepal, P. insigne and P. villosum in the lower
sepal, and P. Spicerianum alone in the staminode.
(15) P. x a. Pomone.—P. insigne predominates alone in the upper
sepal, P. insigne and P. villosum together in the petals, and P. Spicer-
ianum and P. villosum in the staminode.
(16) BP. x a. Vertwmne.—P. Spicerianum and P. insigne together pre-
dominate in the upper sepal and staminode, while P. villosum alone
prevails in the petals.
(17) P. x a. amena.—P. Spicerianum and P. insigne together pre-
dominate in the upper sepal, P. insigne alone in the lower sepal, and
P. Spicerianum alone in the petals and staminode.
(18) P. x a. Cyrus.—P. insigne alone predominates in the upper
sepal; P. insigne and P. villosum together preponderate in the petals ;
and P. Spicerianum and P. villosum prevail in the staminode.
(19) P. x a. delicatulum.—P. Spicerianum alone predominates in
the upper sepal ; P. insigne and P. villosum together preponderate in
the petals; and P. Spicerianum and P. insigne together prevail in the
staminode.
(20) P. x a. Mellona.—P. Spicerianum and P. insigne together pre-
dominate in the upper sepal and staminode; P. insigne alone pre-
ponderates in the lower sepal; while P. insigne and P. villosum together
prevail in the petals.
(21) P. x a. Micias.—P. insigne alone predominates in the upper
sepal; while P. insigne and P. villosum together preponderate in the
petals, and P. Spicerianum and P. villosum together in the staminode.
(22) P. x a. tigrinwm.—P. Spicerianum and P. insigne together
predominate in the upper sepal; P. insigne alone preponderates in the
lower sepal; P. Spicerianum alone in the petals; while P. Spicerianum
and P. villosum together prevail in the staminode.
Apart from the above prepotencies the parts of these twenty-two
hybrids are fairly intermediate in colour between the three ancestral
I
114 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
species. The second set of hybrids to illustrate the variability of second-
ary hybrids and the law of Partial Prepotency consist of twenty-four
plants, all raised from the same seed-capsule by Mr. Reginald Young, of
Liverpool, out of P. Boxalli (Pfitz), var. atratum, by P. x politum, the latter
being itself a hybrid between P. barbatum and P. venustum. (Figs. 33-38.)
For the sake of convenience I will class these unflowered hybrids as
forms of what I believe to be the original hybrid of the same parentage,
viz. P. x Pluto, raised by Messrs. Low, of Bush Hill Park, using
Roman numerals from I. to XXIV. to distinguish the individual varieties.
The following diagram will show the pedigree at a glance :—
DIAGRAM SHOWING THE Two Parents AND Four GRANDPARENTS OF
PaPHIOPEDILUM x PxiuTO (vars.).
P. P. | P.
12
|
B. B. barbatum venustum
3 2
Hie: eae Fig. 36. A ere oe Fig. 38.
1p. 12
Boxalli x politum
atratum
3 f
_ Fig. 33. Fig. 34.
PapHiopEDILUM x PuuTo (vars.).
According to the Galtonian law, these varieties of the hybrid P. x
Pluto should show, on the average, } P. Boxalli + } P. x politum + }
P. barbatum + } P. venustum; or to put it more simply, 4 P. Boxalli
+ 1 P.barbatum + + P. venustum.
The following facts will show the disturbing factor of Partial Prepo-
tency in regard to the habit, form, and colour of the leaves.
Prepotencies in Habit, Form, and Colour of Leaves.
P. x Pluto, 1.—The parent P. Boxalli is prepotent in habit and form,
while the grandparent P. venustum predominates in colour of leaves.
P. x Pluto, 1I.—The grandparent P. venustum predominates in
colour of leaves.
P. x Pluto, ITI.—P. Boxalli alone predominates in habit, while P.
Boxalli and P. venustum together preponderate in colour of leaves.
P. x Pluto, 1V.—P. Boxalli alone predominates in habit, while P.
Boxalli and P. barbatum together preponderate in colour of leaves.
P. x Pluto, V—P. Boxalli predominates in form, while P. venus-
tum preponderates in habit and colour of leaves.
P. x Pluto, VI.—P. Boxalli predominates in habit, while P. venus-
tum preponderates in colour of leaves.
P. x Pluto, VIJ.—P. Boxalli predominates in habit and colour,
while P. barbatum prevails in form of leaves.
P. x Pluto, VIII.—P. Boxalli alone predominates in habit and form,
while P. barbatum and P. venustum together preponderate in colour of
leaves.
EXPERIMENTS IN HYBRIDISATION, &c. Ti5
P. x Pluto, [X.—P. Boxalli and P. venustum together predominate
in habit, while P. Boxalli and P. barbatum together preponderate in
colour of leaves.
P. x Pluto, X.—P. Boxalli and P. venustum together predominate
in habit, while P. Boxalli and P. barbatum together preponderate in form
of leaves.
P. x Pluto, XI.—The grandparent P. barbatum alone predominates
in form, while the grandparents P. barbatum and P. venustum together
preponderate in colour of leaves.
P. x Pluto, XIJ.—P. Boxalli alone predominates in habit and form,
while P. Boxalli and P. venustum together preponderate in colour of
leaves.
P. x Pluto, XIII.—P. barbatum alone predominates in form, P.
Hig. 35. Eira. 36: Fie. 37. Fie. 38.
P. Boxauut. P. Boxattt. P. BARBATUM. P. VENUSTUM.
‘Fic. 33.—P. BoxaLLI ATRATUM. Fia. 34.—P. x PoLITUM.
Two Parents and four Grandparents of Paphiopedilum x Pluto vars. I.-XXIV.
venustum in habit, while P. Boxalli and P. venustum together prevail
in colour of leaves.
P. x Pluto, XITV.—P. Boxadliand P. barbatum together predominate
in habit, form, and colour of leaves.
P. x Pluto, XV.—P. Boxalli and P. barbatum together predominate
in habit and colour, while P. Boxalli and P. venustum together prepon-
derate in form of leaves.
P. x Pluto, XVI.—P. barbatum alone predominates in habit, while
P. Boxalli and P. barbatum together preponderate in form and colour of
leaves.
P. x Pluto, XVII.—P. Boxalli alone predominates in habit ; P. Box-
12
~_
116 © JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
alliand P. barbatum together preponderate in form; and P. Boxalli and
P. venustum together prevail in colour of leaves. ©
P. x Pluto, XVIII.—P. venustum alone predominates in habit; P.
barbatum alone preponderates in form; while P. Boxalli and P. venustum
together prevail in colour of leaves.
P. x Pluto, XIX.—P. barbatum alone predominates in habit, while
P. Boxalli and P. barbatum together preponderate in form and colour of
leaves.
P. x Pluto, XX.—P. Boxalli and P. venustum together predominate
in habit and form of leaves.
P. x Pluto, XXI.—P. Boxalliand P. barbatum together predominate
in habit, while P. Boxalli alone prevails in form and colour of leaves.
P. x Pluto, XXII.—P. barbatum alone predominates in habit and
form, while P. Boxalli and P. barbatum together preponderate in colour
of leaves.
P. x Pluto, XXIII.—P. Boxalli and P. venustum together predomi-
Fic. 39.—Papuiopepitum x Puuro vars. I._XXIV.
(P. Boxatur atrattm 9 x P. x potrtum 3.)
nate in habit; P. barbatum alone preponderates in form ; and P. Boxalli
alone in colour of leaves.
P. x Pluto, XXIV.—P. venustum alone predominates in habit; P.
barbatum alone preponderates in form ; while P. barbatum and P. venus-
tum together prevail in colour of leaves.
All the hybrids, without exception, show distinct traces of both the
parental and ancestral species, but in different proportions. Certain in-
dividual parts of some of the hybrids are fairly well balanced between
their three pedigree species; in other parts one or other of the three
species clearly predominates ; while in other parts, again, any two of the
three species prevail; and so on through all the variations, the
changes being rung on the different parts by the three pedigree species,
both in form and colour, giving rise to numerous variations. Indeed, in
the one case detailed above, out of twenty-four hybrids raised from the
EXPERIMENTS IN HYBRIDISATION, &c. ti?
same seed-capsule, no two are alike, and yet all show distinct traces of
their ancestry, and well illustrate the law of Partial Prepotency.
One point may be noted here that comes out clearly in an examina-
tion of the above hybrids, and that is the latency of certain characters
in the first generation which come out markedly in the second generation.
The hybrid parent of these twenty-four hybrids, P. x politum, fails
to show the colour characters of one of its own parents, P. barbatum, in
the leaves ; yet in a number of cases these same colour characters re-
appear strongly in the second generation, clearly showing that certain
characters may remain latent in one generation to reappear in the next.
THe Fertiniry oF Hyprips.
The question of the fertility of hybrids is very important both to the
student and to the practical breeder. Ifahybrid, 7.e. a first cross between
two distinct species, be not fertile, its further improvement by crossing
is obviously barred; but if it prove fertile in however small a degree,
then in the hands of the skilled hybridist it may prove to be the starting-
point of a series of variations of great economic value.
Amid the many misconceptions concerning hybrids in the popular
mind perhaps none has clung so tenaciously as the belief in their absolute
infertility. In studying the records of our foremost hybridists—Kolreiiter,
Gartner, Herbert, Darwin, Kerner, Naudin, and Dr. Focke—one is im-
pressed at once with the undoubted fertility of many hybrids, and I
have compiled a list of genera from these authorities, and from my own
observations, in which fertile hybrids are known. I find that no less
than ninety distinct genera are recorded in which fertile hybrids are
known, and only four in which the hybrids are all quite infertile.
This list is doubtless incomplete, yet it may possibly serve a useful
purpose in demonstrating the undoubted fertility of many hybrids, and
the rare absolute infertility of others,
In the natural order Composite we have fertile hybrids in Cirsium,
Inula, Chrysanthemum, Senecio, Hieracium, Lactuca, and Tragopogon.
In Rosacez we have Prunus, Pyrus, Fragaria, Geum, Rosa, Rubus,
and Cratzgus.
In Ranunculacez : Anemone, Aquilegia, and Clematis.
In Gesneraceze : Achimenes, Streptocarpus, Isoloma, and Gloxinia.
In Carophyllez : Silene, Lychnis, Melandrium, and Dianthus.
In Lilacew: Scilla, Chionodoxa, and Chionoscilla.
in Solanacex : Solanum, Datura, Nicotiana, and Petunia.
In Scrophularinee : Calceolaria, Veronica, Verbascum, and Linaria.
In Amaryllidee : Hippeastrum, Crinum, Narcissus.
In Campanulacee : Campanula and Lobelia.
In Geraniacez : Pelargonium and Ciconium.
In Ericacew : Rhododendron and Erica.
In Cucurbitacez : Cucumis and Cucurbita.
In Onagrariee : @nothera and Epilobium.
In Graminee : Triticum and Aigilops.
In Leguminose : Cytisus, Medicago, Pisum, and Phaseolus.
In Malvacee: Abutilon and Lavatera.
In Orchidew : Paphiopedilum, Phragmipedilum, Calanthe, Cattleya,
118 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Dendrobium, Disa, Epidendrum, Lelia, Uelio-Cattleya, Masdevalla,
Phalenopsis, Odontoglossum, Thunia, and Chysis. ©
While in other natural orders we have fertile hybrids in Cotyledon,
Begonia, Quercus, Gladiolus, Vitis, Cereus, Viola, Canna, Brassica,
Nymphea, Primula, Lamium, A%sculus, Berberis, Mirabilis, Salix,
Mentha, Passiflora, and Fuchsia.
On the other hand, we have those genera whose hybrids, so far as
experiments have yet been made, are all absolutely infertile. After a
careful search I have only been able to find four of these—namely, Ribes,
Polemonium, Digitalis, and Papaver—and in none of these have many
experiments been made.
To my mind, negative results, though useful in their way, are never
safe guides to follow. I have observed many cases in the Orchidez where
again and again certain species have refused to cross, yet at another time,
and under other conditions, quite unexpectedly have produced fertile seeds ;
and I think that one may reasonably expect even these four recalcitrant
genera to produce fertile hybrids in the course of time.*
In regard to the ninety genera which have produced fertile hybrids, it
may possibly be argued that many of them are not true hybrids, because
they have been raised from closely related species; but even if this be
eranted, what about the numerous fertile hybrids from very distinct
species? For instance, the species of Leelia (Lindl.) and Cattleya (Lind1.)
respectively are still classed as distinct genera by our best botanists; and
I think that the most easy-going systematist would admit them to be
distinct species, yet hybrids raised between these two genera are very fertile.
But perhaps the best practical proof of the fertility of hybrids is the
numerous hybrids raised in gardens, of many generations, from several
species.
(1) For instance, fertile hybrids have been raised by Messrs. Sutton &
Sons, of Reading, between Solanum tuberosum and §. Maglia, forty-one
seedlings being raised from two hybrid plants of the first generation.
(2) Cytisus x preecox, a hybrid between C. albus and C. purgans, seeds
freely in my garden, and many plants have been raised in nurseries ;
these are the second generation of two species.
(8) As mentioned in another part of this paper, I have raised 500
plants from seeds of Berberis x stenophylla, itself a hybrid between the
two species B. Darwinii and B. empetrifolia.
(4) Mr. James has raised a large batch of seedlings from five hybrid
Senecios, themselves the product of S. cruentus and 8. Heritieri.
(5) Scilla bifolia and Chionodoxa Lucilliz cross naturally in gardens,
and their hybrids, Chionoscilla x Alleni, seed very freely.
(6) Some of the best forms of Narcissus in gardens are the result of
hybrids between N. poeticus and N. obvallaris, recrossed with one or other
of the parent species.
(7) Our fine garden Strawberries of the present day have been raised
from many generations, of two species at least, viz. Fragaria virginiana
and I’. chiloensis, and probably in some cases, such as the variety ‘ St.
Joseph,’ from F. vesca alpina.
* Since the above paper was written, M. Vilmorin, of Paris, tells us that he ne
succeeded in obtaining fertile hybrids in Papayer.
> Chronicle.)
| jJavanicum ?
(To face page 118.)
Fie. 40,—RuopopEeNnpron x Numa, AND 17s PRoGENrrons. (Gardeners’ Chronicle.)
PEDIGREE : —
(2) R. jasminiflorum 7<--(6) R. javanicum 2
|
(8) Brookianum racile g\-(7) Princess Royal 9
i
|
(9) javanieum g-(8) Duchess of Teck 9
|
(4) indicum ¢ | ++(10) Lord Wolseley 9
Azalea indica ‘ Stella’ |
(11) multicolor Curtisii g~+(5) indico-javanicum ?
|
(1) Noma.
(To face page 118.)
niflorum 9
‘
..8)
(To face page 118.)
Ftc. 41.—Rnopopenpron x Eos. (Gardeners' Chronicle.)
(a, R. Monancn; x, I
sc, R. MALAYANUM.)
PEDIGREE :
R, javyanicum ¢ ~-R. jasminiflorum >
R. javanieum g ~+R. Lobbii 9 R. jasminifloram g~-R. Princess Royal ¢
RK. Duchess of Rdinburgh ¢ { R. Brincenedlex under! ?
R. malayanum ¢~-R. Monarch 9
R. Bos
(To face page 118.)
EXPERIMENTS IN HYBRIDISATION, &c. 119
(8) Hybrids between Aquilegia californica and A. chrysantha, and A.
cerulea and A. chrysantha crossed water sc, by Mr. James Douglas,
yielded an extraordinary variety of forms, being several generations of
three species.
(9) The new race of Streptocarpus, raised at Kew, are from the inter-
crossing of hybrids between the three species, 8. Dunni, S. Rexi, and S.
parviflorus. *
(10) Our garden Roses are the product of the hybridisation through
many generations of at least three species, viz. R. gallica, R. indica,
and R. multiflora; while Lord Penzance has raised hybrids between R.
lutea and R. rubiginosa which are fertile, both self-crossed, and also with
the race of Hybrid Perpetuals, raised originally from R. gallica and R.
indica. Here we have hybrids of four distinct species.
(11) The Amaryllis or Hippeastrum of gardens have been derived from
hybrids of many generations, of several species.
(12) Gladiolus x Nanceianus is a hybrid of the third generation,
uniting the four species G. psittacinus, G. oppositiflorus, G. Saundersi,
and G. purpurato-auratus.
(18) The Orchid-flowering Cannas ‘ Italia,’ ‘Austria,’ ‘ Burbank,’
&e., are the third generation of four species, namely C. iridiflora, C. War-
scewiczii, C. glauca, and C. flaccida.
(14) In Paphiopedilum (Pfitz) (known in gardens as Cypripedium),
twenty-eight hybrids have been recorded, each combining in its pedigree
four distinct species.*
(15) Rhododendron ‘Kos,’ raised by Mr. Heale, for Messrs. Veitch,
of Chelsea, is a hybrid of the fourth generation, of four distinct species,
viz. R. javanicum, R. jasminiflorum, R. Lobbii, and R. Malayanum ;
while R. ‘Numa,’ raised by the same firm, is a hybrid of the fifth
generation, and contains the five following species :—R. javanicum, R.
jasminiflorum, R. Brookianum racile, R. indicum (Azalea indica Stella),
and R. multicolor Curtisu. (Figs. 40 and 41.)
But there is another phase of the question, which is of some import-
ance, and that is the diminished fertility of some hybrids as compared
with the fertility of natural species, and it is here probably that the
popular idea of the infertility of hybrids first arose. Darwin, who made
a most elaborate survey of the whole question, used the word ‘“ sterility,”’
not in the general sense of barrenness, 7.¢. absolute infertility, but simply
in the sense of diminished fertility, standing as it were midway between
complete fertility and absolute infertility ; so that when he wrote of the
“sterility of hybrids,” he simply meant their lessened fertility, and not
their infertility as most people seemed to imagine. Darwin, after careful
research and many experiments, came to the following conclusion upon
the whole matter, that “the sterility of distinct species when first
united, and that of their hybrid offspring, graduates by an almost infinite
number of steps from zero (when the ovule is never impregnated and a
seed-capsule is never formed) up to complete fertility.”t This general
statement is as true to-day as it was then. Darwin then goes on to say
that “... this high degree of fertility is, however, rare.’’ Recent
* See Orch. Rev. iv. p. 361.
+ Animals and Plants, 2nd ed. ii. p. 163.
120 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
experiments have demonstrated that this high degree of fertility is no
longer rare, so that Darwin’s sentence, ‘‘ This high degree of fertility is,
however, rare,” might now read, “ This high degree of sterility is, how-
ever, rare.”
Some statistics I prepared some time ago,* and now made up to date, serve
as an illustration of this from the Orchidew. During the past seven years
Mr. Reginald Young, of Liverpool, the well-known orchidist, has been cross-
ing inter se some 30 distinct species and 58 distinct hybrids in the genus
Paphiopedilum (Pfitz), and has kindly placed his stud book at my disposal,
in which are precisely and carefully recorded no less than 849 crosses.
Of these, taken together, 80°2 % have proved fertile, 7.e. produced good
seeds. Of 263 crosses between distinct species 95:0 % were fertile. This
seems to show that in this genus crosses between distinct species are
almost, if not quite, as fertile as crosses between varieties of the same
species (taking the latter at complete fertility, 2.e. 100% ); while in
crosses in which a hybrid was concerned in the parentage, out of 586,
only 73°5 % proved fertile, showing that crosses with hybrids, though
fertile to a high degree, are yet rather less fertile than crosses between
species.
A further analysis of the figures shows that while hybrids crossed
with the pollen of pure species give 91°8 % fertile, yet pure species
crossed with the pollen of hybrids give but 60 % tertile. This seems to
point to the conclusion that the slight decline in the fertility of
hybrids is due in a large measure to the loss of power in the pollen
of hybrids.
This decline of power in the male element of hybrids is very curious,
but has been observed before in other plants by Darwin, Dr. Focke, Dr.
Maxwell Masters, and Prof. Macfarlane, and also by Prof. Ewart in his
Zebra hybrids. Practical breeders will therefore be wise, in crossing
hybrids with species, to always use the pollen of species in preference to
that of hybrids.
It is quite possible that domestication or cultivation may in time eradi-
cate this decline in the fertility of hybrids, for I observe that in my hybrid
Berbevis x stenophylla, the first hybrids between the two wild species
flower more profusely, but bear fewer berries than the parent species ;
while the hybrids of the second generation are much more profuse in their
berry-bearing, being apparently more fruitful even than the wild species.
It very often happens that the pollen of very young hybrids is not so effec-
tive as that of those of more mature growth. Mr. Reginald Young believes
this to be so with his Paphiopedilums ; and Dr. Focke records a case of a
hybrid Sinningia in which the pollen of the second year of flowering
was better than that of the first. The decline of fertility is by no means
confined to hybrids alone ; for instance, certain races of Primula sinensis
raised by Messrs. Sutton, of Reading, have proved difficult to perpetuate
owing to their diminished fertility, and these are cross-breds, not hybrids,
being raised within the limits of one species.
In the face of these facts, therefore, we must conclude that fertility
depends more upon the conditions of life than upon hybridism, and there
is no reason why hybrids should not in time become as fully fertile as
cross-breds usually are.
* See Jowr. Roy. Hort. Soc. xxi. (April, 1898], p. 485
EXPERIMENTS IN HYBRIDISATION, &c. 121
THe STABILITY OF HyBRIDs.
Next to the question of the fertility of hybrids, perhaps the most im-
portant to the practical breeder is the constancy or stability of hybrids
fertilised with their own pollen. If, as is generally supposed, hybrids do
not breed true to themselves, but. are inconstant and tend to revert to
their grandparent species, then is the breeder’s work vain, and the econo-
mic importance of hybrids considerably diminished. With a view to
ascertain more precise facts than are at present on record in regard to this
question, I have carried out some experiments in the genus Berberis,
raising a large batch of B. x stenophylla from self-fertilised seed.
Berberis x stenophylla is a primary hybrid between B. Darwinii and
B.empetrifolia, originally raised by Messrs. Fisher & Holmes, of Hands-
worth, Sheffield.
The two parent species are very distinct. The one (B. Darwinii) has
a vigorous and upright habit of growth, while the other (B, empetrifolia) i
weak and drooping in habit. In the one the stems are thick, much
branched, and covered with short, woolly, brown hairs; while the other
has slender stems, little branched, and quite glabrous. In the one the
spines are seven in number—short, spreading, and flat—while in the
other they are three (one long and two short), set like an inverted T, each
rounded and grooved below. In the one the leaves number three to four,
broad, flat; with five to seven spiny teeth, shiny green above, lighter
below ; while in the other the leaves are seven to nine, linear, closely
revolute, erect, sharply mucronate, dull, dark green above, silvery below.
In the one the flowers are racemose, six to twelve, orange-yellow, shaded
with red without, pedicels rich red, flower segments long and narrow ;
while in the other, the flowers are single or sub-umbellate golden yellow,
on slender green pedicels, segments short and broad.
The hybrid B. x stenophylla is intermediate in most characters
between the two parent species. Its habit of growth is very
vigorous, first upright and then drooping gracefully; stems me-
dium thickness, branches long, pendent, slightly pubescent, with three
spines of equal size. Leaves variable, four to nine, narrow, partly
revolute, sub-erect, mucronate, dark green above, silvery green below.
Flowers, sub-umbellate, one to six, deep yellow, pedicels reddish, seg-
ments intermediate. Altogether the hybrid is fairly intermediate, though
B. empetrifolia is prepotent in the number and habit of the spines ; in all,
favouring that parent as 13 : 12, or 52 per cent. Five hundred seedlings
of this hybrid were raised, and of these no less than 90 per cent. repro-
duced the characters of the parent hybrid faithfully and well, with little
variation ; while the remaining 10 per cent. varied from a form repre-
senting about 66 per cent. of the grandparent B. empetrifolia, through a
series of intermediate forms up to an extreme one, which reproduced
about 67 per cent. of the characters of the grandparent B. Darwin. It
is worthy of notice that not one plant out of the 500 completely reverted
to either of the ancestral species, No. 18 being the nearest to B. Darwinii,
and No. 1 the nearest to B. empetrifolia.
The following condensed analysis of thirty of the most variable of
these secondary hybrids will show at a glance how they differ from one
129 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
another, and how far they seem to have reverted towards their grand-
parents. Indirectly, too, they serve to illustrate once more the law of
Partial Prepotency.
Berberis x stenophylla vars. 1 to 30.
h=habit, f=form, c=colour.
(1) B. empetrifolia is prepotent in h and f of stems, h, f, and ¢ of
spines, in h, f, and ¢ of leaves, and in h, f, and ¢ of flowers. In all,
favouring that ancestor as 23 : 12, or 65°7 per cent. This form is the
nearest reversion to B. empetrifolia in the whole batch, but traces of B.
Darwinii still remain in all the parts, especially in the colour of the
stems.
(2) B.empetrifolia is prepotent in h and f of stems, in h of spines, in
h, f, and ¢ of leaves, and in h of flowers. Altogether favouring that
ancestor as 19 : 12, or 61:2 per cent.
(3) B. empetrifolia is prepotent in h, f, and ¢ of stems, in h of spines,
and in c¢ of leaves; in all, favouring that ancestor as 17: 12, or 58°6
per cent.
(4) B. Darwinii is prepotent in h, f, and ¢ of stems, in h, f, and ¢ of
spines, in f of leaves, and in h, f, and ¢ of flowers; altogether favour-
ing that ancestor as 22 : 12, or 64°7 per cent.
(5) B. Darwinii is prepotent in c¢ of stems, and in h, f, and ¢ of
flowers, while B. empetrifolia predeminates in h of spines and in h and ¢
of leaves; in all, favouring B. Darwinii as 16 : 15, or 51°6 per cent.
(6) B. empetrifolia is prepotent in h, f, and ¢ of stems, in h and ¢ of
spines, and in h, f, and ¢ of leaves; altogether favouring that ancestor
as 20 : 12, or 62°5 per cent.
(7) B. Darwinii is prepotent in f and ¢ of stems, in f and ¢ of leaves,
and in h, f, and ¢ of flowers, while B. empetrifolia predominates in h of
leaves ; in all, favouring B. Darwinii as 19 : 18, or 59°3 per cent.
(8) B. empetrifolia is prepotent in f and ¢ of stems, in h and ¢ of
spines, in h, f, and ¢ of leaves, and in h and f of flowers, while B.
Darwinii predominates in ¢ of flowers; in all, favouring B. empetrifolia
as 21 : 13, or 61°7 per cent.
(9) B. empetrifolia is prepotent in f of stems, in h and ¢ of spines, in
h, f, and ¢ of leaves, and in h of flowers, while B. Darwinii predominates
in f and c of flowers; in all, favourmg Bb. empetrifolia as 19 : 14, or
57°5 per cent.
(10) B. Darwinii is prepotent in f of stems, in f of leaves, and in
f and ¢ of flowers, while B. empetrifolia predominates in ¢ of leaves; in
all, favouring B. Darwinii as 16 : 13, or 55:1 per cent.
(11) B. empetrifolia is prepotent in h of stems, in h, f, and ¢ of spines,
and in f of leaves, while B. Darwinii predominates in f of stems, in ¢ of
leaves, and in h of flowers; in all, favouring B. empetrifolia as 17 : 15,
or 53°1 per cent.
(12) B. empetrifolia is prepotent in f of stems, in h and ¢ of spines,
in f and ¢ of leaves, and in h of flowers, while Bb. Darwinii predominates
in h of leaves; in all, favouring B. empetrifolia as 18:13, or 58:0
per cent. ;
(13) B. empetrifolia is prepotent in h, f, and ¢ of spines, in h, f, and ¢
EXPERIMENTS IN HYBRIDISATION, &=. 123
of leaves, and in h and f of flowers; altogether favouring that ancestor
as 20 : 12, or 62°5 per cent.
(14) B. empetrifolia is prepotent in h of spines and in h, f, and «, of
leaves, while B. Darwinii predominates in f and c of flowers; im all,
favouring B. empetrifolia as 16 : 14, or 55°35 per cent.
(15) B. Darwinii is prepotent in f and ¢ of spines and in h, f, and ¢
of leaves, while B. empetrifolia predominates inf andc of stems and
in f of flowers; in all, favouring B. Darwinii as 17:15, or 53:1 per
cent.
(16) B. empetrifolia is prepotent in h and f of stems, in ¢ of spines,
and in f and ¢ of Jeaves, while B. Darwinii predominates in f of spines,
in h of leaves, and in f and ¢ of flowers; in all, favouring B. empetrifolia
as 17 : 16, or 51°5 per cent.
(17) B. Darvwinii is prepotent in f and ¢ of stems, in f of spines, in h
and f of leaves, and in h and ¢ of flowers, while B. empetrifolia predomi-
nates in h of spines, in ¢ of leaves, and in f of flowers ; in all, favouring
B. Darwinii as 19 : 15, or 55:8 per cent.
(18) B. Darwinii is prepotent all round in h, f, and ¢ of stems, spines,
leaves, and flowers, yet distinct traces of B. empetrifolia are to be found
in all the parts. This form is the nearest reversion to the grandparent
B. Darwinii in the whole batch, favouring that ancestor as 24 : 12, or
66°6 per cent.
(19) B. Darwinii is prepotent in h, f, and ¢ of stems, in h, f, and ¢
of spines, in f and ¢ of leaves, and in h and c of flowers, while B. em-
petrifolia predominates in h of leaves and in f of flowers; in all, favour-
ing B. Darwinii as 22: 14, or 61°1 per cent.
(20) B. empetrifolia is prepotent in c of stems, in h of spines, and ~
in h, f, and ¢ of leaves; altogether favouring that ancestor as 17:12,
or 58°6 per cent.
(21) B. empetrifolia is prepotent in f of stems, in h, f, and ¢ of spines,
in h, f, and ¢ of leaves, and in h of flowers; altogether favouring that
ancestor as 20: 12, or 62°5 per cent.
(22) B. empetrifolia is prepotent in h and f of stems, in h of spines,
in h, f, and ¢ of leaves, and in h of flowers, while B. Darwinii predomi-
nates in ¢ of stems; in all, favouring B. empetrifolia as 19:18, or
59°38 per cent.
(23) B. Darwinii is prepotent in c of stems and in f of leaves; while
B. empetrifolia predominates in h of spines and ¢ of leaves; altogether
fairly intermediate (though very different at first sight from the typical
hybrid) as 14 : 14, or 50 per cent.
(24) B. empetrifolia is prepotent in h, f, and c of spines and in h, f,
and ¢ of leaves; altogether favouring that ancestor as 18:12, or 60 per
cent.
(25) B. empetrifolia is prepotent in fof stems, in h of spines, and in
h and ¢ of leaves, while B. Darwinii predominates in h of flowers; in all,
favouring b. empetrifolia as 15:13, or 53°5 per cent.
(26) B. empetrifolia is prepotent in h and c of stems, in h, f, and ¢
of spines, in f and c of leaves, and in h of flowers; altogether favouring
that ancestor as 20: 12, or 62°5 per cent.
(27) B. Darwinii is prepotent in ¢ of stems, in h, f, and ¢ of leaves,
124 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
and in h, f, and ¢ of flowers, while B. empetrifolia predominates in h of
spines; in all, favouring B. Darwinii as 19 : 13, or 59-3 per cent.
(28) B. empetrifolia is prepotent in h, f, and ¢ of spines, in h, f, and
c of leaves, and inhandf of flowers, while B. Darwinii predominates
in c of flowers ; in all, favouring B. empetrifolia as 20:18, or 60°6 per
cent.
(29) B. Darwinii is prepotent in f and ¢ of stems, in h, f, and ¢ of
spines, and in fof leaves; in all, favouring that ancestor as 18: 12, or
60 per cent.
(80) B. Darwinii is prepotent in ¢ of stems, in f and c¢ of spines,
and in f and ¢ of leaves, while B. empetrifolia predominates in h of
leaves; in all, favouring B. Darwinii as 17: 138, or 56°6 per cent.
In addition to the above experiments with Berberis, there are several
cases on record which tend to show the stability of hybrids in the
Orchidex, e.g.—
Paphiopedilum x Harrisianum, a hybrid between P. barbatum (Pfitz)
and P. villosum (Pfitz), has been raised true from seed when fertilised with
its own pollen, both by Mr. W. Grey, for Hon. Erastus Corning, Albany,
U.S.A., and by Mr. R. M. Grey, for Mr. Graves, of Orange, N.Y.
M. Pauwels, of Boterlaere, France, crossed two distinct varieties of
this same hybrid, which duly reproduced the specific characters of P. x
Harrisianum faithfully and well.
Again, Mr. W. Grey raised P. x vexillarium, a hybrid between P.
barbatum and P. Fairieanum (Pfitz), from self-fertilised seed. Messrs.
Veitch, of Chelsea, raised Epidendrum x O’Brienianum, a hybrid between
K. radicans (Pav.) and E. evectum (Hook. f.), from self-fertilised seed ;
but one of the seedlings, while retaining the characteristic shape of the
hybrid, almost reverted 7 colour to its grandparent, KH. evectum.
This is another illustration of Partial Prepotency, one of the grand-
parents being prepotent in colour only.
Dean Herbert—the great pioneer of hybridisation in this country—
crossed Petunia nyctanigeneflora with P. pheenicea; and the hybrid so
raised reproduced itself perfectly true from seed, a large batch of seedlings
being raised.
Thus the popular idea that hybrids, when self-fertilised, always revert
to one or other of the ancestral species is evidently not founded on fact.
Where this is supposed to have been the case it may possibly have
been due to the hybrid being accidentally fertilised with the pollen of one
of the ancestral species.
THe Vicour oF HyBRIDs.
Most hybrids between distinct species are remarkable for their
vigorous habit and large size. Many, too, are more profuse and precocious
in their flowering than their parent species. But the vigour of hybrids
seems to depend chiefly on their being out-crosses as opposed to being
inbred. For I observe in my hybrid Berberis that those of the first
generation, raised by crossing the two wild species, are much more
vigorous than their parents; but those of the second generation, raised
from the first hybrid fertilised with its own pollen, are, as a whole, less
vigorous, being fairly normal in this respect. Yet my hybrid Paphiopedi-
EXPERIMENTS IN HYBRIDISATION, &c. 125
lums of the second generation, raised from a first hybrid, out-crossed again
with a third species, are more vigorous even than the first hybrids, being
quite abnormal in this respect. This seems to show that out-crossing
continues to increase the vigour of hybrids abnormally, while inbreeding
tends to reduce their vigour to a normal state.
Tue Liuits oF CROSSING.
In referring to the question of the fertility of hybrids, we saw upon
what slight conditions sterility sometimes depends ; and yet, if the con-
ditions be favourable, it is remarkable what extreme forms of plants can
be united by hybridisation. For instance, in the Orchidex, during the
past decade not only have many distinct species been successfully united,
but, as we have already seen, numbers of distinct genera hybridise to-
gether with ease.
The four genera Lelia, Cattleya, Epidendrum, and Sophronitis are
now all united by hybridisation, as are Zygopetalum, Colax,and Bate-
mannia. These hybrids have all flowered in gardens, and show the
characters of their parent genera. In addition to these are numerous
records of generic crosses, yet unflowered, though plants or seeds have
been produced.*
The most extreme of the flowered generic hybrids in Orchidee are
apparently those between Phaius and Calanthe, genera belonging to dis-
tinct sub-tribes, so that the generic limit even has now been surpassed,
and that of the sub-tribe reached. Is it possible to go farther than this ?
I think so, the relationship between many of the generic hybrids, yet
unflowered, being much more remote.
I have made a number of experiments in crossing distinct genera in
the Orchidez, and, though many failures have resulted, yet some have
proved rather interesting. For instance, Sophronitis x Cattleya,
Sophronitis x Lelia, Paphiopedilum x Phragmipedilum, Cypripedilum
x Phragmipedilum, Paphiopedilum x Cypripedilum, Oncidium x
Odontoglossum, all produced healthy capsules, containing some good
seeds, many of which are now germinating; while Lycaste x Lelia,
Angrecum x Lelia, Angrecum x Vanda, Paphiopedilum x Odonto-
glossum, and Paphiopedilum x Dendrobium all produced fully developed
capsules, which opened naturally in due time, but which contained no
good seeds. Again, Ada x Lelia, Cattleya x Angraecum, Dendrobium
x Odontoglossum, Epidendrum x Dendrobium, Epidendrum x Odonto-
glossum, Cattleya x Dendrobium, all produced partly formed capsules,
which ultimately faded ; while Lelia x Lycaste, Dendrobium x Cattleya,
Paphiopedilum x Cattleya, Epidendrum x Dendrobium, and Epidendrum
x Paphiopedilum all failed to set capsules.
Incompatibility of structure, apart altogether from systematic affinity,
may have something to do with the limitation of crossing, for I observe
in the above experiments that in all the instances where Sophronitis was
crossed with Cattleya, when Sophronitis was the seed parent, good seeds
were obtained, which duly germinated ; while the reverse crosses, made at
the same time and under the same conditions, in every case failed to set
a capsule.
* See Jour. Roy. Hort. Soc. xxi. [1898], p. 468.
126 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Now Sophronitis has a very short column, while Cattleya has a
decidedly long one, and one can quite understand that while it would be
an easy matter for the pollen tubes of Cattleya to reach the ovules of
Sophronitis ; yet, on the other hand, it would be much more difficult for
the pollen tubes of Sophronitis to reach the ovules of Cattleya, owing to
the length of the column duct in the latter.
Incompatibility of colour seems to have something to do with the
limitations of crossing, for Darwin gives us a large number of facts where
colour varieties of the same species were more or less infertile when
crossed.
The limits of crossing do not seem to be determined so much by
systematic affinity or natural relationship; for, as we have seen, some
very distinct genera cross with ease, while some closely allied species
refuse all attempts to unite them. I have found Oncidium flexuosum
always infertile when pollinated with its own pollen, yet quite fertile
when fertilised with pollen of O. Forbesii, a distinct species. Nor do the
limits of crossing depend upon constitutional differences, for annuals
can be crossed with perennials, deciduous trees with evergreens, plants
from the tropics with plants which reach to the Arctic Circle. To sum up
the whole question, we can only ascertain the true limits of crossing by
actual experiments.
It is encouraging to find that the more experiments made, the more
barriers there are removed, the wider become the limits of crossing.
The main thing is not to be discouraged by failures, but to try again and
again, and above all to keep precise records, both of the successes and the
failures, which records may prove to be of inestimable value to science.
(End of the first day’s Conference.)
CONFERENCE. 127
CONFERENCE,
WEDNESDAY, JuLY 12, 1899, at WESTMINSTER.
Introductory Remarks by the Rey. Professor Gro. Henstow
M.A., V.M.H.
I have been asked by our Secretary to take the place of Sir Michael
Foster, who, I am sorry to say, is seriously ill, confined to his bed, and
cannot possibly be with us to-day, I regret this very much, and so, I
am sure, shall we all, as from Sir Michael we should have had a most
valuable introductory address. At the very last moment I have been
asked to open the proceedings. You will not therefore expect me to
give you an introductory address, as I said almost all I had to say
yesterday. But there is just one remark I should like to make. The
great value of these meetings is that we connect together the scientific
aspect with the practical. Not only does this apply to hybridisation, but
to all departments of botany. The botanist studying physiological laws
of plants would only be too thankful to get the facts which the hybridist is
familiar with; while by the bringing forward of the scientific aspect,
the practical man’s work is much expedited. So we work, and should
always work, hand in hand.
128 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
WORK OF THE UNITED STATES DEPARTMENT OF
AGRICULTURE ON PLANT HYBRIDISATION.*
By Hersert J. WEBBER, in charge of the Plant- breeding Laboratory.
WHILE some work on plant-breeding has been in progress in the United
States Department of Agriculture for a number of years, until recently it
has been almost wholly in the line of simple selection without the direct
application of hybridisation and cross-breeding. The work on hybridisa-
tion proper as a means of securing variations and improvements was
started only a few years ago, and as yet all the work is in an uncompleted
state. Some points of interest have been secured, however, and I shall
briefly describe some of these in this paper. The work thus far under-
taken has been mainly on Oranges, Grapes, Pineapples, Pears, Apples,
Wheat, Corn, and Cotton. It will not be possible to discuss all of the
experiments in progress, and features will be selected here and there
which it is thought will be of interest to the members of the Conference.
The work on Oranges and Pineapples which will be described has been
conducted by the writer in conjunction with Mr. Walter T. Swingle, and
equal credit should be given him for any factors of importance brought
out. Owing to the unfinished condition of the work this paper will largely
treat of the improvements which it is desired to secure, with an indication
of the progress made.
ORANGE HYBRIDISATION.
The work on the hybridisation of the Orange and other citrous fruits
was begun in 1893, but was greatly interrupted by the severe freezes in
the winter of 1894 and 1895, and again last winter, February 1899,
when a number of the hybrids which would have fruited this year were
frozen down. We have secured about 2,000 citrous hybrids which are
being grown and tested, but none of these have yet fruited, and the com-
parisons given below are accordingly based entirely on foliage characters,
habits, &e.
A Hardy Orange.—The most important development that we are
striving to produce in citrous fruits is a hardy Orange which will withstand
the severe frosts that occasionally cause such serious damage in the Orange
regions of the United States. This we hope to secure by hybridising the
Japanese Trifoliate Orange (Citrus trifoliata) with the various varieties
of the Common Sweet Orange (C. awrantiwm sinensis). The Trifoliate
Orange is a deciduous trifoliolate tree which is perfectly hardy as far
north as New York, and is coming to be used extensively as a hedge
plant. The fruit is small and bitter, and is generally considered worthless :
* In this paper the term “ hybrid” isused, comformable to the Centwry Dictionary,
as a generic term to include all organisms arising from a cross of two forms noticeably
different, whether the difference be great or slight. Adjectives are sometimes used to
indicate the grade of the forms resulting froma cross, such as racial, varietal, or
bigeneric hybrids. Where a hybrid of two races or species is crossed with a third
race or species a triracial or trispecific hybrid would result. (See discussion on this
point in Year-book, United States Department of Agriculture, 1897, p. 384.)
WORK OF THE UNITED STATES DEPARTMENT, &c. 129
it is, however, sometimes used for preserves. It is very late in starting
in the spring, the flowers appearing before the foliage, and not even
showing till the Common Orange is nearly out of bloom. It is thus
regularly about a month later in starting in the spring than the common
Orange and other citrous fruits, and is never caught by late frosts. Again
in the fall it ripens it fruits early, and becomes dormant a considerable
period before the Common Orange. The Common Orange, on the other
hand, is an evergreen unifoliolate tree growing more or less during the
entire winter unless checked by severe cold. Judging from the results
which have been obtained with other plants it seems perfectly possible by
crossing and recrossing the Orange with the hardy trifoliata to ultimately
secure a hybrid combining the fruit characters of the former with the
hardiness of the latter.
Many instances are recorded where hybrids have been obtained com-
bining certain characters of the parents, but only a few are known to the
writer where increased hardiness has been secured. According to Verlot,*
the forms of Rhododendron arborewm are rendered hardier by crossing
with Ff. catawbiense. Macfarlane has called attention to the hardiness of
a hybrid between the hardy Montbretia Pottsw and Tritonia aurea, which
latter is easily injured by cold. He says, referring to the winter of 1891—
92: ‘The corms of the first (Montbretia) appear scarcely to have been
injured. Those of the hybrid have been largely killed off, at least to the
extent of sixty per cent., while 777tonia, never hardy in exposed ground,
has survived only where it is planted against, and can creep along, the
outer side of a hothouse wall.’”’r A second case is also described by
Macfarlane where a hybrid between a hardy and a tender species is
intermediate in hardness between the two. He says: ‘“‘ Philesia buxifolia
is a hardy plant, and resists well our winter colds. Lapageria rosea
requires the temperature of a cold hothouse to flourish, while the bybrid
succeeds if kept protected from frosts and the more cutting winds. In
the southern counties of Britain it lives and flowers out of doors.’+ A
similar case of increased hardiness secured by hybridisation is cited by
Manda: ‘By crossing Rosa Wichuraiana with greenhouse Teas the
result is astonishing, as the plants are not only hardy but retain their
foliage during the winter. Thus a new race of evergreen Roses has been
added to our collection, and promises to be the beginning of a new and
useful class.’
The change desired in the Orange is not so great as one is at first
inclined to think. If by infusing a slight portion of the trifoliata blood
into the Orange we can somehow modify its habits of growth and cause
it to remain more dormant through the winter, and later into the spring,
we have accomplished our aim, and this, we think, is perfectly possible.
The production of Grape hybrids having the resistance to Phyloxera
of certain of the American species such as Vitis riparia and V. rupestris,
* Verlot, Jean Baptiste, “Sur la Production et la Fixation des Variétés dans les
Plantes d’Ornement,” cited in Bailey’s Plant Breeding, p. 145.
+ Macfarlane, Dr. J. M., ‘A Comparison of the Minute Structure of Plant Hybrids
with that of their Parents, and its Bearing on Biological Problems,” Trans. Royal Soc.
Edinburgh, vol. xxxvii. Pt. I. No. 14, p. 258.
{ Manda, W. A., “ Hybrid Wichuraiana Roses,” Gardening, vol. vi. No. 145,
Sept. 15, 1898, p. 9.
K
130 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
and the fine fruits of the European varieties, which it is claimed have
been obtained by certain French hybridisers, is an»accomplishment of
14
ii
—
[=I
x
[Lai of SJ of of o
i ao a4
Fia. 42.—Crrrous Hyprips, SHOWING COMPARATIVE VIGOUR.
this nature. On the other hand it seems within the limit of possi-
bility to secure an early ripening strain, possibly deciduous, which will
be very much hardier than any of the desirable varieties now known.
WORK OF THE UNITED STATES DEPARTMENT, &c. 131
The Common Orange and C. trifoliata are very distinct in character,
and are somewhat difficult to hybridise. In my personal work I find
that, even using the utmost care, only about one twentieth of the flowers
pollinated seem to be affected by the cross, and only about one per cent.
of the flowers cross-pollinated finally mature fruit. There is a further
loss in the small percentage of germination, not more than half of the
seeds germinating. We have secured quite a number of hybrids,
however, where both the Orange and trifoliata were used as the seed-
bearing parent. Some of these plainly show characteristics of both parents,
and are doubtless true hybrids. Out of forty hybrids of the trifoliata
crossed with pollen of the Sweet Orange, twenty-nine resemble the
Trifoliate Orange in habit and foliage characters so far as can be observed,
while eleven are clearly intermediate in these characters. These eleven
intermediate plants are very similar to each other, and apparently derive
certain characters from each parent. The leaves are trifoliolate but
are much larger than those of normal Citrus trifoliata. The central
leaflet has a tendency to enlarge, while the lateral leaflets remain
about the normal size or in some cases are reduced in size. (Compare
fig. 42, which gives a hybrid (772) between its two parent species, all
three being seedlings of the same age.)
The majority of the species of Citrus are polyembryonic, several
embryos developing in one seed, and frequently giving several seedlings
when germinated. This introduces an interesting complication into
citrous hybridising. Strasburger * has shown that the egg cell proper is
apparently fecundated in the normal way, and develops into a single
embryo, and that the other embryos are developments from certain cells
of the nucellus (the mother tissue), near the apex of the embryo sac,
which become enlarged and divide, and finally push out into the embryo
sac, forming what are termed adventive embryos. When fully
developed in the mature. seed, these adventive embryos cannot be
distinguished from the embryo developed in the normal way from ‘the
fecundated egg cell. In many cases a seed from a hybrid fruit has
yielded more than one seedling, and in several instances seedlings from
the same seed are of totally different character, showing that one has
been affected by the hybridisation while the others are like the mother
parent. In such cases it seems evident that the intermediate seedling
which shows the effect of the male parent is from the embryo, . resulting
from the development of the fecundated egg cell, while the seedlings
resembling the mother parent only, are developed from the adventive
embryos, which, as explained above, arise directly from cells of the mother
parent without any intervention of the male element.
In the pot shown in fig. 48, No. 2, three seedlings are developing
from a single seed of a Tangerine Orange which was crossed by Mr.
Swingle with pollen of trifoliata. One of the seedlings has trifoliolate
leaves, while the other two have unifoliolate leaves like the mother parent.
There can be no possible doubt that these three seedlings come from the
same seed, as this difference was plainly visible when the seedlings were
about an inch high, and fearing that there might be an error I carefully
*Strasburger, Dr, Eduard, “ Ueber Polyembryonie,” Jenaische Zeitschr. fiir
Naturwissensch. XII. '
K 2
182 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
dug up the seed and found them still connected with the cotyledons and
all encased in the same seed coat. The same precaution was taken in
another similar case, and the fact of the occurrence of such cases, is
beyond a question of doubt, whatever be the interpretation. There can
be but little doubt that here the trifoliolate seedling comes from the
embryo developing from the ege cell proper, and shows the effect of the
hybridisation, while the other two seedlings resembling the Tangerine
mother plant are from adventive embryos. It should also be noticed
that the leaves of the trifoliolate seedling are much larger than those
of typical trifoliata, as is plainly shown by a comparison with a
Fic. 43.—TrRurE anp Fatsre Crrrous Hysrips.
trifohata seedling shown in fig. 43, No.1. A similar case, of different
parentage, is shown in fig. 43, No. 3. The seed of No. 3 was the result of a
cross made by Mr. Swingle of trifoliata with pollen of the Sweet Orange.
Here the seedling with large leaves is doubtless from the embryo affected
by the hybridisation, while that with fewer and smaller leaves resembling
true trifoliata (in this case the mother parent) is doubtless from an
adventive embryo. The reciprocal hybrids of the above, when the
Sweet Orange is used as the mother parent and the ¢trifoliata as the
father parent, several of which have been secured, frequently exhibit the
same phenomenon (see fig. 45, No. 1). Similar cases have occurred
among our hybrids of Orange and Pomelo, and Orange and Tangerine.
WORK OF THE UNITED STATES DEPARTMENT, &c. i15}3)
Ali of the forty hybrids of the Trifoliate Orange crossed with Sweet
Orange mentioned above were from a single fruit. In the case of the
eleven seedlings which plainly show intermediate characters there can
be but little doubt but that they are all from embryos developed from
egg cells proper, and thus true hybrids. In the case of the twenty-nine
hybrids which show no effect of the male parent itis very doubtful whether
they may not be developments from adventive embryos. It seems prob-
aye - hig
| oe oe be eo
2 t a
SRE ANIM ST te NN RO I TY STP
ee
RS ee: ee esi
sisi ta 2b
=
SLAB Oh
, on im | ,=, 2,2 elm, mi) =)
ee
Fig. 44.—Trvur anp Fausre Hyprivs FRoM THE SAME FRuIT or C. TRIFOLIATA x
CG. AURANTIUM SINENSIS.
able that the fecundation of a few seeds of a fruit may stimulate the
development of other seeds not fecundated, where the only embryos
formed are developed adventively, and are not affected by the hybridisation
except indirectly so far as the stimulation to development is concerned.
In the pots shown in fig. 48, Nos. 1 and 4, two seedlings have developed
from a single seed in each case, and in neither case do either show any
effect of having been crossed with the Sweet Orange. Those seedlings
from hybridised fruits, which show no effect of the male parent, and
134 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
seem to come from adyentive embryos, I shall speak of here as “ false ”’
hybrids for the sake of clearness. .
Another feature of importance shown by the true hybrids is their
evergreen habit. In March, when the seedlings were transplanted to the
south, all of the false hybrids (fig. 44, lower row) were dropping their
leaves as true Trifoliate Oranges normally do in the winter. All of
the true hybrids, however (fig. 44, upper row), as yet showed no
signs of dropping their foliage, and were clearly distinct in this feature.
This is also shown well in fig. 48, No. 8, where in two seedlings from
the same seed the hybrid is evergreen, while the false hybrid has lost
nearly all its leaves.
The increase in vigour, which is so commonly displayed by hybrids
between distinct parents, is also shown by these hybrids to a marked
degree. Fig. 44 (upper row) shows a representative series of nine of
the true intermediate hybrids, which is to be compared with a repre-
sentative series of the false hybrids shown in the lower row of the same
figure. The true hybrids are all much larger and more branched than the
false hybrids, which are, as explained above, supposed to be developed
from adventive embryos, and thus to be true representatives of the mother
parent. The growth is also much more rapid and vigorous than in the
normal male parent, which may be seen by comparing fig. 42, where all
seedlings are of the same age. No. 845, a cross of two typical Oranges
and one of the largest of 500 seedling Oranges of similar kind, is yet far
smaller than the medium-sized true hybrid No. 772. No. 780, one of the
largest of the twenty-nine false hybrids, affords a relative comparison of
size of the true hybrids with the type of the mother parent. The true
hybrid No. 772 used here for comparison is not the largest of the hybrids
secured, but is of medium size. (See fourth in series, fig. 44, upper row.)
In case two or more seedlings develop from the same seed, the one
developing from the egg cell and affected by the crossing with the male
element, is almost invariably the strongest and largest, which is, of
course, what would be expected. (Fig. 48, No. 2, and fig. 45, No. 1.)
The hybrids described above are of trifoliata crossed with pollen of
Sweet Orange, but the reciprocal hybrids obtained show the same
characters and about an equal proportion of intermediate plants or true
hybrids. Of fourteen hybrids of Sweet Orange crossed with pollen of
trifoliata nine seedlings are, so far as can be observed, exactly like the
typical mother parent, and are possibly false hybrids, while five are inter-
mediate in nature, resembling the male parent in having trifoliolate
leaves, which are much larger than typical trifoliata. (Fig. 45, Nos.
1 and 2, and fig. 46, No. 716.) It is interesting to note that here, where
the Sweet Orange is used as the mother parent, in the five cases of seed-
lings showing intermediate nature all are trifoliolate, though coming
from seeds of an unifoliolate species, and show almost exactly the same
intermediate characters as are shown by the reciprocal hybrids, where
the trifoliata is used as the mother parent and the Sweet Orange as the
father parent.
In crosses of the Tangerine (Citrus nobilis) with pollen of the Trifo-
liate Orange the same feature is exhibited. Of twelve such hybrids
eleven resembled the Tangerine in foliage characters, &c., while one has
WORK OF THE UNITED STATES DEPARTMENT, Kc. 135
trifoliolate leaves, somewhat larger than the normal leaves of trifoliata,
clearly showing the influence of the pollen parent. It is interesting to
note here also that the trifoliolate seedling is the largest of the series.
Loose Skin of Mandarin.—A second improvement of importance
which it is desired to produce is a fruit having the quality and flavour of
the finest varieties of the Common Orange with the loose, easily removable
skin of the Mandarin type of Orange (C. nobilis). With this object in
view a number of hybrids have been made, principally between the
Tangerine, the best sort of Mandarin Orange in cultivation, and various
varieties of the Common Orange. Citrus nobilis is much more closely
related to the Common Orange than the C. trifoliata, and the hybrids
seem to be much more variable in the first generation, some very closely
resembling the parents, while others are apparently intermediate as far
Fic. 45.—Hysrivs or Sanprorp’s MEDITERRANEAN (C. AURANTIUM SINENSIS) x
C. TRIFOLIATA.
as can be judged from foliage characters. Here, however, the characters
of the parents are more nearly alike, and it is only in the extreme varia-
tions that the foliage resemblances can be clearly distinguished. In
almost every case, however, the great majority of the seedlings resemble
the mother parent in the main, while comparatively few show plainly
the effect of the male parent. Among 286 hybrids of the Tangerine
crossed with pollen of Common Orange 247 seemed mainly to resemble
the Tangerine in foliage characters, while thirty-nine show more
resemblance to the Common Orange.
The reciprocal hybrids, where the Common Orange was crossed with
pollen of Tangerine, show the same features, the majority of the seed-
lings resembling the mother parent, and only a small percentage of them
showing the effect of the male parent. In fig. 47, showing seven
seedlings of the Ruby Orange 2 x Tangerine ¢ , the large seedlings in Nos. 1
JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
136
‘SdINdAPT SQOULID ASIV,T GNV ANT, AO SHAVAT—"OF “OL
EY PO ER a
WORK OF THE UNITED STATES DEPARTMENT, &c. Tt
and 3 resemble the mother parent mainly, while the large seedlings in
Nos. 2 and 4 show the effect of the father.
It is equally important to secure fruits of the Pomelo type, which have
the easily removable skin and easily separable segments of the Mandarin
type of Orange, and to secure improvements in this direction many
hybrids of the Tangerine and Pomelo have been made. The resulting
seedlings, as in the case of the Tangerine Orange hybrids, mainly resemble
the mother parent ; but the Pomelo foliage being more markedly different
from the Tangerine than that of the Orange, the differences are much
plainer. Of 116 hybrids of the Pomelo crossed with pollen of Tan-
gerine 111 had plainly the broad-winged petioles and robust foliage of the
female parent, while only five showed the foliage characters of the Tan-
gerine or male parent. No reciprocal hybrids were made in this case.
1 2 3 4
Fic. 47.—-Hysrivs or Rusy Orance (C. AURANTIUM SINENSIS) x TANGERINE (C. NOBILIS).
Change of Quality—Among the varieties of citrous fruits now culti-
vated are several fairly desirable fruits, quite distinct in their characters,
which from their appearance seem to be hybrids of the Orange
(C. awrantium sinensis) and Pomelo (C. decumana). The variety known
as the Aurantium-Pomelo is so called because of its supposed hybrid
nature. A fairly well-known Jamaican Pear-shaped Pomelo of small
size, with orange-yellow skin and Pomelo-like pulp, seems also to bea
hybrid between these two species. We have made quite a number of
crosses of these species, hoping to secure fruits markedly different from
those now in cultivation, and which will prove valuable commercial
varieties. Of 126 hybrids of the Pomelo with pollen of the Orange 106
resembled the mother parent and twenty the male parent.
138 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Resistance to Disease—The Sour Orange (C. awrantiwm amara) has
been found by extended observations to be largely immune to the so-called
“ blight,’’ which is probably the worst Orange disease known in Florida.
Hoping to secure desirable sorts of sweet edible Oranges immune to this
disease, the Orange was crossed with pollen of the “ Bitter Sweet,’
which is the best variety of the Sour Orange. The twenty-seven hybrids
of this parentage are the most variable of any set or combination of
citrous hybrids which we have obtained. Some have leaves almost
exactly like the Bitter Sweet, others almost exactly like the Orange,
others present a totally distinct shape of leaf from either parent. Of
these twenty-one resemble in main the mother, and six in main the male
parent.
Other hybrids were made for various minor improvements, but it is
not desirable to discuss them further here.
Summary of Resemblances of Citrous Hybrids.—In the hybrids of
the widely distinct species the seedlings divide themselves plainly into
two classes: (1) Those resembling the mother parent entirely, so far as
could be determined ; and (2) those intermediate in character.
Total number | Number re- | Number inter-
Parentage of seedlings ceva mother mediate
Trifoliata 2 x Sweet Orange ¢ : | 40 | 29 11
Sweet Orange 9 x Trifoliata 3 Sel 14 | 9 | 5
Tangerine 9 x Trifoliata 3 é | 12 ial | 1
In the hybrids of closely related species, such as Orange x Pomelo
and Orange x Tangerine, the intermediate nature of the hybrids, if they
are intermediate, cannot be easily distinguished. In foliage and other
characters, so far as exhibited previous to fruiting, they seem to resemble
very closely either the mother or father parent. The following table will
show the propegont of their resemblance :—
j
| Number resem-
Total number Number resem-
Parentage of seedlings | bling mother | bling father
Tangerine 9 x Sweet Orange ¢ : : 286 | 247 39
Sweet Orange 9 x Tangerine o : : 15 69 6.
Pomelo 2 x Tangerine g. A ; : 116 abl 5
Pomelo 9 x Sweet Orangeg . : ; 126 106 20
Sweet Orange 2 x Pomelo¢ . ; ; 103 95 8
Sweet Orange 9 x Bitter Sweet gd . 27 21 6
West Indian Lime 2? x Sicily Lemon ¢ . if) 9 2
Sicily Lemon 9 x West Indian Lime @ . 9 | 9 0
West Indian Lime 2 x Pomelo ¢g . d 4 4 0
PINEAPPLE HYBRIDISATION.
The principal problems here presented are to secure—l, better
shipping sorts; 2, smooth-leaved sorts; 8, sorts resistant to disease ;
and 4, sorts having larger fruits of better quality. These objects
have been kept clearly in view in all of our work. Pineapples, as is well
known, are almost totally seedless. Among the fruits which reach the
American markets from the Bahamas, West Indies, and Florida it is
WORK OF THE UNITED STATES DEPARTMENT, &c. 139
very seldom that a perfect seed is found. So rare is this that most
people, and even some botanists, consider it to be a totally seedless fruit.
It is interesting to note here that the stigmas are apparently always
abundantly dusted with pollen from the same flower, and it is plain that
they are either self-sterile or that the pollen is imperfect. A microscopic
examination, however, of the pollen of the Red Spanish variety showed
the polien to be perfectly normal so far as could be judged.
In the spring of 1896 I crossed a number of flowers of the Mauritius
Pineapple with pollen of the Red Spanish variety simply as a_ pre-
liminary trial to see whether seeds could be induced to set by crossing
different sorts or varieties. In this experiment a number of apparently
perfect seeds set, some fifteen of which germinated and grew. In the
spring of 1897 Mr. W. T. Swingle made numerous other crosses, and the
following year, the spring of 1898, I continued the work myself. As a
result of this work we now have some 500 seedlings showing many
interesting foliage variations. The 24-month-old seedlings have reached
a height of 6 or 8 inches, being as large as the slips commonly used in
planting fields, and it would seem from their size that many will fruit in
the summer of 1901. If size and rapidity of growth can be taken as
an indication they surely will not require eight years from seed to
fruit, as I have seen somewhere stated.
In the course of the work it has been observed that certain sorts are
apparently sterile to each other’s pollen, no seeds setting even when care-
fully crossed. As an illustration, fifty flowers of Pernambuco crossed
with pollen of Porto Rico gave no seeds; and thirty-nine flowers of Porto
Rico crossed with pollen of Pernambuco, the reciprocal cross to the above,
also gave only one single seed, and that imperfect.
In my own experience the most fertile varieties are the Abbaka
and Smooth Cayenne, two of the finest varieties known. Ninety-seven
flowers of Abbaka crossed with pollen of Smooth Cayenne gave seventy-
seven good seeds, and, in the case of the reciprocal cross, thirty-six
flowers of the Smooth Cayenne crossed with pollen of Abbaka gave forty-
six perfect seeds. Other sorts used in crossing, such as Golden Queen,
Ripley, Red Spanish, Mauritius, &¢., gave varying degrees of fertility
between these two extremes.
Corton HyYBRIDISATION.
The production of Cotton is one of the most extensive industries of
the Southern United States, and furnishes many problems to tax the
skill of the plant breeder. The so-called Sea Island Cotton, Gossypiwm
barbadense, grown in a limited area mainly on islands near the coast of
Georgia and South Carolina, furnishes the longest and finest staple pro-
duced anywhere in the world. The Upland Cotton, Gossypium herbaceum,
which is the kind grown all over the interior, produces a comparatively
short and coarse staple. If by hybridising the fine Sea Island with the
different varieties of the Upland a race can be secured suitable to growth
in the interior regions, and yielding a finer and longer staple, the industry
will be greatly benefited. This would seem to be a comparatively simple
problem, but it is complicated by the necessity of securing, not only a
“IQODIA WAILVUVEINON DNIMOHS ‘SENUUVG SLI GNV GINdAPL NOLL — "sp “YT
H
WORK OF THE UNITED STATES DEPARTMENT, &c. 141
longer and finer staple, but, to be of any value, it must be borne on a
smooth black seed, like the Sea Island type, so that the fibre can be ginned
J ‘ bate! > > . ’
Fic. 49..-SEEps or Hyprip Corron AND OF ITS PARENTS, WITH THE FIBRE PULLED OUT
TO SHOW THE RELATIVE LENGTH AND AMOUNT IN EACH CASE,
M, Fibre of ‘ Sea Island’; F, of ‘Upland’; H, of ‘ Klondyke,’ the Hybrid between them.
142 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
on a roller gin. In the ordinary Upland, where the fibre varies from } to
1: inches long, the seed is covered with a dense coating of short hairs—
is a “tufted ’’ seed as the growers say—and this prevents the use of the
roller gin, a saw gin being necessitated. The saw gin tears the fibre so
seriously that there is no object in increasing its length unless it is borne
on a smooth seed, so that the roller gin can be used. Mr. W.A. Clark, a
careful planter, of Columbia, South Carolina, who is co-operating with
the Department of Agriculture in this work, early realised the difficulties
in the problem and took up the first necessary step—the production of a
smooth-seeded strain of the Upland Cotton. This he secured, after five or
six generations of careful selections, in a strain which he called the
‘ Klondike.’
In the ordinary sorts of Upland Cotton smooth black seeds, similar to
those of the Sea Island Cotton, are occasionally found mixed with the
ordinary tufted or green seeds. Originally certain Upland sorts, such as
Peterkin, had smooth seeds, and the production of such seeds in sorts
commonly having tufted seeds may be due to hybridisation of the ancestors
of the plant with the Sea Island or some smooth-seeded sorts of the
Upland.
Mr. Clark selected at random and planted a quantity of smooth black
seeds from the ordinary Upland Cotton, and the great majority of the
resulting plants produced the ordinary tufted seed ; but a few had mainly
smooth black seed like those from which the plants were grown. Seeds
were selected from the few plants which produced mainly smooth black
seed, and were planted the second year. This season a much larger pro-
portion of the plants produced smooth black seed, but still many pro-
duced the ordinary tufted seed. Seeds were again selected from the
plants producing smooth seed and planted the third year, and so on
through five generations, when the character was fully fixed and all the
plants came true, producing only the smooth black seed.
The ‘ Klondike’ was then hybridised with the Sea Island, and while it
is too early to pronounce as to the practical value of the hybrids secured,
some are exceedingly promising, having fibre intermediate in length and
fineness between the two parents, and more abundant than in either
(fig. 48, H). It is also interesting to note that here, again, the increased
vigour so commonly resulting from hybridising different species and
races is very markedly exhibited in many cases.
A second important problem in Cotton breeding which is receiving
attention is the production of a tawny Cotton of a grade similar to the
Egyptian, which is extensively imported into the United States, and
manufactured largely into fine underwear, &c. The Egyptian varieties so
far as yet tested in the United States have failed to give satisfactory
results, and it seems that races especially adapted to conditions obtaining
there must be secured. Experiments are under way in crossing the
varieties of the Sea Island and Upland grown in the United States with
the Egyptian races, and with the dark brown Pieura or Peruvian Cotton
with a hope of securing brown or tawny races suited for culture in the
United States which will take the place of the tawny Egyptian Cotton
now imported.
WORK OF THE UNITED STATES DEPARTMENT, &c. 143
Corn oR Maize HyBripisATION.
Only very few of the numerous important problems here presented to
the plant breeder have as yet been taken up. In the hope of securing
better-yielding races the exceedingly large-kerneiled Cuzco, or Peruvian
Corn recently imported into the United States by the Department of
Agriculture, was used in hybridising with certain of our best races.
The Hickory King, a very large-kernelled white dent, and Leaming, a
well-known yellow dent, were used as the seed-bearing parents. The
Cuzco, from which the pollen for the hybrids was obtained, was grown
from kernels of a graphite colour, this colour being distinct from that of
any race of Corn in the United States with which I am familiar.
The current or immediate effect of pollen (xenia), so commonly
reported as occurring in Corn, was shown in these hybrids; and although
no check experiments were made (the work not being carried on to
demonstrate this feature), there can nevertheless be no doubt that the
coloration was due to the effect of the pollen. The seed of the Hickory
King and the Leaming used was grown by careful seedsmen, and strict
attention was given to keeping it pure and true to type. None of the
ears except those which had been crossed showed any indication of
impurity. Some of the kernels of the Hickory King ears crossed with
the pollen of the Cuzco showed irregular spots of the characteristic
graphite colour of the Cuzco, while others were entirely of a slate colour,
these being somewhat lighter in colour than those of the typical Cuzco.
So far as could be observed, the Cuzco used was not a fixed type, some of
the kernels being mottled with red, olive purple, or brown. In a few
instances the immediate effect of the pollen was apparent in Leaming
crossed with Cuzco,* the kernels showing a peculiar admixture of the
colours of the parents, that is of dark olive purple and the orange yellow.
In the case of the hybrids of Hickory King with Cuzco grown from
kernels showing the immediate effect of the pollen, which were marked
when planted, their increased vigour, purple stalks, and whorls of anchor
roots (inherited from the Cuzco, the male parent) showed that they were
without question hybrids of the two races named. In the same charac-
teristic way the influence of the male parent was evident in many of the
hybrids from kernels in which no immediate effect of the pollen was
shown. All hybrids showing intermediate characters were very late in
flowering, which is another characteristic of the Cuzco, it being a tropical
plant, and therefore requiring a long season to develop. These hybrids
as a rule matured slightly earlier than the Cuzco plants in the same
field.
Other hybrids have been made with a view of securing sorts that will
yield better in northern regions, where flint Corn, which ripens early but
is a poor yielder, is now grown. Some of these hybrids are very
’ promising; for instance, one of Gilman Flint (a good race of the flint
Corn) when crossed with Leaming pollen produced ears almost twice as
large as those produced by the Gilman Flint grown under similar con-
ditions, there being sixteen rows of kernels on the ear instead of twelve,
* The crosses of Leaming with Cuzco were made by Mr. E. C. Rittue, gardener
of the Division of Vegetable Physiology and Pathology, at my request.
144 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
as in the Gilman Flint, and the kernels being much larger. This hybrid
ripened nearly as early as the Gilman Flint, being secure from injury by
frost three months after it was planted.
It is the intention of the Department to test such hybrids in the
regions to which they seem best adapted, and to fix races of such as are
found valuable.
CONCLUSION.
What has been said above will serve to show the character of the
work on plant breeding, which it is the intention of the Department of
Agriculture to foster, and also to call attention to some of the important
problems which are now receiving attention. The vast diversity of soil
and climatic conditions afforded by our great extent of territory renders
it necessary for us to have very many different sorts of cultivated plants.
An important and almost illimitable field is thus opened for the plant
breeder, and we hope that the work on this subject in the Department of
Agriculture may soon assume such scope and magnitude as its importance
demands.
EXPLANATION OF FIGURES.
Fig. 42.—Citrus hybrids, showing comparative vigour: 772, hybrid of
Citrus trifoliatag x C. aurantium sinensis $, a medium-sized seedling
selected from nine hybrids of same parentage ; 780, type of female parent
(C. trifoliata), one of the largest of thirty seedlings; 845, type of male
parent (C. awrantiwm sinensis), one of the largest of nearly five hundred
seedlings. These three seedlings are all of the same age.
Fig. 48.—True and false citrous hybrids: No. 1, false hybrids of
C. trifoliata? x C. aurantiwm sinensis $ from same seed, both hybrids
resembling the female parent only; No. 2, three, hybrids of Tangerine
Orange (C. nobilis)@ x C. trifoliatag from one seed, the largest, with
trifoliolate leaves, being a true hybrid, while the two small ones, resembling
the female parent only, are false hybrids; No. 3, two hybrids of C. tri-
foliata? x C. aurantium sinensis 8, both from same seed, the one on
the left, with large leaves, being a true hybrid, and the one on the right,
with small leaves, being a false hybrid ; No. 4, two false hybrids of
C. trifoliata? x C.aurantium sinensis g , both from same seed, resembling
female parent only.
Fig. 44.—True and false hybrids from same fruit of C. trifoliata? x
C. aurantium sinensis $, showing comparative size. Upper row true
hybrids, lower row false hybrids.
Fig. 45.—Hybrids of Sandford’s Mediterranean (C. awrantiwm sinen-
sis)? x C. trifoliatad. Trifoliolate seedlings in pots Nos. 1 and 2 are
true hybrids, being intermediate between the two parents; the others are
apparently false hybrids, resembling the female parent only.
Fig. 46.—Leaves of true and false citrous hybrids: 715 and 716,
false and true hybrids respectively of Sweet Orange (C. awrantium)2 x
C. trifoliatag ; 778 and 745, false hybrids of C. trifoliata? x C. awran-
tium sinensis & ; 772 and 777, true hybrids of C. trifolatag x C. awran-
tium sinensis.
Fig. 47.—Hybrids of Ruby Orange (Citrus awrantiwm sinensis)? Xx
Tangerine (C. nobilis) é: No. 1, seedling resembling female parent; No. 2,
WORK OF THE. UNITED STATES DEPARTMENT, We. 145
largest seedling, intermediate between parents, two small seedlings,
apparently false hybrids; No. 3, seedlings resembling female parent ;
No. 4, seedling resembling male parent.
Fig. 48.—Cotton hybrid and parents, showing comparative vigour:
F, Upland Cotton, female parent ; M, Sea Island Cotton, male parent; H,
Hybrid. (These plants were photographed under the direction of Mr.
W. A. Clark.)
Fig. 49.—Seeds of hybrid Cotton and of parents, with fiber pulled
out to show length and amount: IF’, ordinary Upland, female parent ; M,
Sea Island, male parent; H, Hybrid.
DISCUSSION.
The CHAarRMAN: We are all greatly indebted to Mr. Webber for his
admirable lecture, and also to the Government of the United States for
having sent him to tell us what they are doing. His lecture has been a
practical illustration of the remarks I made at the beginning, of science
and practice working harmoniously together for the mutual benefit of
each.
Mr. C. C. Hurst: I should like to ask Mr. Webber, in the case of
those hybrids which he said resemble one parent or the other, to be kind
enough to tell us whether they resemble one parent in all characteristics,
or simply in one or two.
Mr. Wesser: In all, so far as can be observed. In growth,
character of the stem, and so on, they resemble one or the other parent.
Mr. Batrson: I should like to know whether Oranges, when grown
from seed fertilised with pollen of the same variety, produce good fruit.
As I understand it, they are not propagated generally by seed. .
Mr. Wesser: So far as the Orange is concerned, Oranges always
produce Oranges. Seedlings of the Orange give Oranges ; and seedlings
of the Pomolo give Pomolo. Crossings of different species seem to be
very rare.
The CHarruan: You spoke just now about a nucleus fertilising the
germ cell, and thereby giving one hybrid plant out of three seedlings,
the other two of which represented the female. I should like to know
whether you have ever had two representing the male and one the female
out of the three.
Mr. Wepser: In answering that question it is necessary to bear in
mind that in these cases we have differences. In some instances we
note supernumerary embryos developing. In the case of Oranges I think
they are developed from the cells. In the case of double fecundation the
nucleus unites with the two pollen nuclei, which finally produces an
endosperm; but secondary embryos are not developed from that endo-
sperm, and, as | understand it, we cannot expect any case of double
fecundation.
146 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
THE STRUCTURE OF CERTAIN NEW HYBRIDS (PASSIFLORA,
ALBUCA, RIBES, BEGONIA, &c.).
3y Jonn H. Witson, D.Sce., F.R.S.E., St. Andrew’s University.
THE prediction made by Sabine, in 1820, when describing the first known
hybrid Passion-flower,* that “the production of plants of a similar
description will probably be great hereafter,’ has been amply fulfilled.
The number of hybrids is now very considerable, and their diversity
bewildering. It is not my intention, however, to attempt to describe, or
even to compile a new list of, all Passion-flower hybrids. The following
notes must necessarily be restricted to an account of my own experiments
at St. Andrews, and to the description of the few hybrids I have been
able to raise there.
PASSIFLORA BUONAPARTEA X P. CH RULEA.
My earliest experiment succeeded admirably, it being the application
of the pollen of P. cerulea to a flower of P. Buonapartea.r The fruit
held and ripened. A little further out on the same branch another flowe r
received pollen of P. Constance Elliot, a variety of P. cerulea, but in
this case the fruit fell before it was fully developed. I do not possess
exact measurements of the fruit secured, but I understand that it was
not so large as the fruit of P. Buonapartea when fertilised by its own
pollen. It was plump, and contained 370 seeds, the majority of which
looked healthy. They were sown in my absence, and their welfare care-
fully attended to, but only one germinated. I believe that a reasonable
time was allowed for others to appear before the soil was thrown out.
This solitary seedling grew vigorously, and produced its first flower in
May 1892. A figure and description of the new hybrid, under the name
P. Margaret Wilson, are givenin the Gardeners’ Chronicle, vol. xxv.
srd ser., 1899.
Comparison of the hybrid P. Margaret Wilson with its Parents.
The following abbreviations will be used :-—
B. = P. Buonapartea.
C. = P. caerulea.
M.W. = P. Margaret Wilson.
STEMS.
The young stem and branches of B. are stout, tetragonal, winged,
light green.
* Trans. Hort. Soc. vol. iv. p. 267.
+ This Passion-flower is stated to be itself a hybrid between P. qwadrangularis
and P. alata. I have had some difficulty in satisfying myself that it is distinct from
P. quadrangularis. It would seem that there are varieties of the latter in cultivation,
some of which are almost identical with P. Buonapartea. It may be remarked that
P. alata and P. quadrangulavris are often confused in collections and nurseries. Very
probably seedlings of both, differing more or less from the types, are often cultivated,
and hybrids between them, other than P. Buonapartea, may also be grown under
specific names.
t The description of the microscopic structure of these and other organs is reserved.
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 147
In C. they are much less stout, almost cylindrical, with five, some-
times six, well-defined angles, between which are several minor ridges ;
glaucous green, with a good deal of reddish-purple, which is often confined
to the ridges.
In M.W. the branches are rather stouter than in C. and much more
distinctly angular. There are commonly five angles, one of them being
less prominent than the rest. The minor ridges are indistinct. Much
purple coloration exists.
STIPULES.
The stipules of B. (fig. 50) are lanceolate, acuminate, slightly oblique,
4 to ,, in. long, } to ? in. broad, narrowing to the base; the margin almost
entire, or very inconspicuously serrate.
In C.* (fig. 52) they are much larger, often more than 1 in. long and
4, in. broad; in form like a cordate leaf halved longitudinally, the apex
prolonged into an awn-like point, } in. long.
In M.W. (fig. 51) the stipules partake of the characters of those
of both parents in a marked way. They are obliquely ovate, dentate
Fie. 50.— P. Buonarartea. Fic. 51.—P. Margaret Winson. Fic. 52.—P. c#RULEA.
SrreuLes (nat. size). '
on the longer side, acuminate or ending in a sharp point which is
usually } in. long. The entire length of the stipule is often § to 1 in.,
and the width} to2in. The largest observed measured 14 in. long
and 1,), in. broad.
LEAF-STALKS.
The leaf-stalks of B. (fig. 58) are strong, 14, to 24 in. long, having one
sharp mesial ridge along the dorsal (under) side continuous with one of
the wings of the stem, and a shallow channel on the upper side. The
upper edges are interrupted by two pairs of light-green sessile glands, the
one pair being placed about } in. beneath the base of the lamina, and
the other pair nearly half-way between the upper pair and the base of the
stalk. The glands are cup-shaped, directed laterally, and in large leaves
the orifices may measure ,), in. across,
In C. (fig. 55) the leaf-stalks are sub-cylindrieal, flattened on the upper
side. They may reach the length of 14 in., and some red coloration is
commonly present. They bear two, three, or four stalked glands, both
glands and stalks being dark purplish-green. The stalks are often ;', in.
long. Their distribution is rather irregular. When only two are present
* A very careful account of the structure of P. caerulea is given by Sabine, assisted
by Lindley, loc. cit. pp. 262-265.
148 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
(the usual number in leaves of average size), they are commonly close to
each other, near or below the middle of the leaf-stalk ; if three, the third
is higher up; if four, they may appear in pairs, one pair being as above
described, and the other close to the base of the leaf-blade ; or, finally,
they may all be at different points on the petiole.
In M.W. (fig. 54) the leaf-stalks are slightly channelled along the
x\
WZ
ie
©
|
Fe
|
|
ioe ©
JHW
Fic. 53.—P. Buonapartrea. Fic. 54.—P. Marcarer Wuiuson. Fie. 55.—P. caRULEA.
LEAF-STALKS (nat. size).
upper side, and rounded on the under side. In large leaves they may
reach the length of 25 in.; a common length is 15 in. The colour is
commonly dull pmk. Four glands are present, usually very nearly oppo-
site, in pairs, one pair being placed close up to the base of the lamina,
or ,', to } in. from it, and the other pair either at. the middle of the
petiole or a little above or beneath it. The glands are light green, with
relatively stout stalks of a darker colour or deeper green.
LEAF-BLADES.
The leaf-blades of B. (fig. 56) are large, ovate-cordate, somewhat
acuminate ; the upper side dark green, the under side lighter green, not
glaucous; the margin entire. The largest example studied was 82 in.
long and 7} in. broad.
The leaf-blades of C. (fig. 58) are characteristically five-lobed, often
seven-lobed by branching of the two lower lobes, occasionally ab-
normally three-lobed, Examples 5 in. long and 7% in. wide have been
noted. The upper surface is deep green, the under surface glaucous, the
veins being often tinged with purple. Minute glands occur at notches on
the margins, near the bases of the lobes.
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 149
Fic. 56.—Lear or P. Buonapartea ( x 3)-
Fie. 57.—Lear or P. Margaret WILSON ( x 3).
iuw
Fie. 58.—Lrar or P. c@RULEA (x 3).
150 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
In M.W. (fig. 57) the leaf-blades are invariably three-lobed. The
length may in very large leaves be 7} in., and the breadth from tip to
tip of the side lobes 10} in.; an average length, however, is 5} in., and
breadth 75 in. Notches with glands occur between the lobes, } to 5 in.
from their base. In younger leaves the veins on the under side are
often dingy purple. In older leaves the purple or red colour is
variable in distribution and intensity, the variability depending on
cultural conditions.
ELOWERS.
The flowers of B. are commonly borne singly in the axils of consecu-
tive leaves on the young branches, and they tend to hang vertically.
Fic. 59.—P. Buonapartes. Fic. 60.—P. Marcarer Wiison. Fic. 61.—P. cmrubea.
FrLowerr-Bups (nat. size).
The peduncle is triquetrous, 1 in. to 1} in. long. The odour is strong,
and not unpleasant. .
In C. the flowers turn upwards to the light by the bending of the
long cylindrical peduncle (the longest 3} in.). They are produced
singly as in B. ‘The odour is comparatively faint and decidedly
unpleasant.
In M.W. the face of the flowers is directed downwards at an angle
of about 45° with the horizon. The peduncle is 1} in. to 24 in. long,
and slightly curved outwards, cylindrical at the base and obscurely three-
cornered distally. The odour is fairly strong and very pleasant, recalling
that of certain Irises. The flowers are borne singly, and continue to be
produced for several months.
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 151
Occasionally in the hybrid, and in both its parents, the flowers borne
at two consecutive nodes open simultaneously.
The bracts of B. (fig. 59, br) are cordate, acute, crenate, 1 to 1} in.
long.
In C. (fig. 61) the bracts are large, ovate-cordate, bluntly rounded
or subacute, entire or very indistinctly crenulate, 1 to 14 in. long and
~ to 1 in. wide.
In M.W. (fig. 60) they are large, ovate-cordate, acute, faintly serrate,
1} to 12 in. long, 1 to 1} in. wide.
SEPALS.
The sepals of B. are oblong, 12 to 14 in. long, 1 to 1} in. wide at
base, the rounded apex extending # to } in. beyond the short or almost
obsolete dorsal mucro. The two outermost sepals are green on the lower
surface; the third pink along one margin; the inner two pink on both
margins; the upper surface of all is reddish-crimson.
In C. the sepals are oblong, slightly keeled, about 1} in. in length,
with an arista of ,°, in. tapering from a vertically expanded base, and
rising ,}, in. from the apex of the sepal. The upper surface is dull
white, with a very faint bluish tinge; the under surface a general light
green.
The sepals of M.W. are 2 in. long, and bear a green arista about } in.
long, | im. from the end. The upper side of the sepals is a clear lilac
rose, shading off to nearly white at the centre. The colour of the under
side is distributed as in B.; the shade, however, is pinkish-purple.
PETALS.
The petals of b. are 2 in. long, } to 2 in. wide; pink on the under
surface and crimson above. The spread of the flower is 44 to 5 in. .
The petals and sepals in the fully expanded flower may fall back until
they form an angle with the floral axis a few degrees greater than a
right angle.
The petals of C. are slightly longer and narrower than the sepals ;
white, faintly tinged with blue. The diameter of the flower is 35 to 4 in.
In strong sunshine, especially when indoors, the perianth bends back a
very considerable distance.
In M.W. the petals are also longer and narrower than the sepals, the
upper side a uniform lilac rose, the under side a lighter shade of the
Same; more or less pouched at the apex. The diameter of the flower is
47 in. when measured from a petal to a sepal opposite, or 53 in. when
from nearly opposite petals. The petals and sepals may spread out until
at 90° with the axis, but they usually lie at a somewhat less angle.
CoRONA.
In the corona of B. the outer faucial rays (fig. 62, a) are in two
whorls ; the rays of equal length ; the average number ninety-three (fifty
in outer and forty-three in inner whorl) ; 2} in. long; rigid and slightly
curved; wavy and delicate at the outer extremity; white at the base,
and conspicuously coloured by five or six alternating bands of white and
Fic. 62.—Srcrion or Fiowrr or P. Buonapartea (nat. size); b7, Bract; s, SEPAL;
p, Petau; a, b,c, OurER, SEcoND, AND MEDIAN SERIES OF CoRONAL APPENDAGES ;
d, AxNutar RipGe; ¢e, Gonopnore. (The styles are figured in perspective.)
Via. 64.—Srcrion or FLrowrer or P. carunea (nat. size).
THE STRUCTURE OF CERTAIN NEW HYBRIDS, tes
rich red or purplish-brown, the colours graduating at mid-length into
mottled mauve-purple ; the tips white, capitate. The rays have a spread
of 25 to8in. In bud they are found bent under the petals, and their
colour is present at a comparatively early stage of their development.
The. capitate tips are beset with papillae, which may be regarded as
glandular. It is easy to demonstrate that the odour of the flower has its
seat in the rays, for when they are cut off the scent disappears.
The corresponding rays of C. (fig. 64, a) are in whorls of a similar
character. When fully expanded they lie straight at a right angle to the
axis of the flower, or the outer ones a few degrees beyond that angle.
The expanse of the rays is a little over2in. The rays are } in. long; the
outer whorl seventy to eighty, and the inner sixty to seventy in number.
The base is white, and immediately above it is a band, % to ;°; in. deep,
of rich purple brown, shading upwards into purple, followed suddenly by
a white ring } in. deep, which merges into a mottled purplish-blue.
The apex is white, non-capitate, and destitute of glandular papille.
In M.W. the corresponding rays (fig. 63, a) are in two whorls,
expanding well out (8} to 3} in.). They are about ninety in number,
the outer whorl having about five more than the inner. The largest
numbers met with were 50+45=95. The length of the inner rays is
12 in., the outer rays 15 in. The basal } in. is deep purplish-brown,
shading quickly into a band of pure white } in. deep; beyond this is a
narrow band of dark greyish-blue, then a very narrow band of pure
white, followed by a dark mauve-purple band (,!) in. deep), which shades
into a lighter tint, and that colour extends throughout the distal half
of the rays. The tips are white and beset with papille, which are
much less conspicuous than those of B., and are often absent in the
outer whorl.
The second faucial series of coronal appendages of B. (fig. 62, b)
consists of (1) anirregular whorl of white, red-tipped, short projections
close to the base of the inner whorl of long rays; (2) a more regular
whorl of similar projections ; and (3) a whorl of appendages, + in. long,
occasionally occurring as single filaments, but more commonly united
in their basal halves into small groups, bearing three to four concentric
bands of red, and tipped with brown purple.
In C. this series of organs consists (fig. 64, b) of a circle of short thin
rays, with very dark-coloured tips. A few black-tipped protuberances are
found irregularly distributed in the region between the circle just de-
scribed and the bases of the long rays.
In M.W. the corresponding series comprises (fig. 63, b) a distinct
circle of very deep brown-purple rays } in. long, almost straight, or
slightly curved outwards; and, external to these, numerous alternately
disposed, mostly shorter, dark-coloured protuberances, situated close to
the base of the inner long rays and lying parallel with them. Occasionally
some of the protuberances described may be found so far displaced
inwards as to give the appearance of a double whorl of short rays when
seen in a section of the flower.
The inner or median series in B. is represented (fig. 62, c) by a flat
white membranous canopy completely covering in the nectary. The free
inner red-dotted edge curves upwards close to the gonophore.
154 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
The corresponding series in C. (fig. 64, c) forms a more complicated
structure. Studied from the base upwards, it presents the following
parts: a basal membranous portion which helps to cover in the nectary ;
a cushion-like expansion placed in close proximity to a projecting ledge
of the gonophore; and a fringe of short delicate red-brown rays which
lean towards and surround the axis.
In M.W. this series (fig. 63, c) forms a membranous tube which
inclines inwards until it approaches very closely to a cup-like projection
of the gonophore, and from the upper edge of the membranous part there
arises a circlet of almost black filaments, } in. long and directed away
from the axis. A slightly developed cushion projects inwards from the
top of the membranous tube.
In B. an annular ridge (fig. 62, d) somewhat incurved downwards,
projects into the closed cavity and forms part of the nectary.
In C. a corresponding ridge occurs, and occupies relatively more space
in the cavity.
In M.W. a similar structure is present, but it exhibits no peculiar
feature. The nectar is copious.
GONOPHORE.
The gonophore of B. (fig. 62, e) is massive, girt in the lower half by
two low ledges, and narrowed very abruptly into a cylindrical shaft which
bears the-stamens and pistil. The lower part is white, and the narrowed
shaft dotted with red.
In C. the base of the gonophore is stout and expands, ;', in. up, into
a flattened collar or ledge. This structure is directed upwards a little,
and widens at its outer edge into a rim which fits the cushion-like en-
largement of the inner coronal appendage already described. The shaft
narrows a little upwards, above the ledge, and is very pale green, without
spots.
In M.W. the gonophore dilates, } in. from the base, to forma cupulate
ledge, the margin of which lies in close proximity to the cushion at the
top of the membranous coronal tube. The shaft tapers upwards gradu-
ally and considerably. Its base is thickly and regularly dotted with elon-
gated red spots, and the upper part is white, with a few dots.
STAMENS.
The filaments of B. are flat, light green, thickly spotted with red on
both upper and under surfaces. The anthers are large and bear plentiful
yellow pollen, the proportion of normal grains being high.
In C, the upper side of the filaments is thickly dotted with faint red
spots. The pollen is golden-yellow and very copious.
In M.W. the filaments are very uniformly dotted with red on both
sides. ‘The anthers are normal in form and size, but, when they dehisce,
instead of being loaded with pollen, as those of the parents are, the faces
are covered with a glutinous, dull yellow exudation. In many cases
undeveloped and shrivelled pollen grains are found embedded in this
substance, and not seldom the grains are sufficiently well developed to
give a brighter yellow colour to the anthers. The best examples of pollen,
however, are probably never quite normal.* ;
* Cf. Masters, Veg. Teratology, p. 463.
THE STRUCTURE OF CERTAIN NEW HYBRIDS, 155
PISTIL.
_ The styles of B. are } in. long, chalky white, with a reddish tinge and
a few faint pink spots at the base. The stigmata are of a pale cream or
grey colour.
In C. the styles are ? in. long; the ground colour very light greyish
or purplish green, dotted throughout with comparatively large reddish-
purple spots. The stigmata are dull greenish-drab.
In M.W. the styles are 5 in. long, with deep purple spots on a light
purple ground; the stigmata purplish-drab. The ovary is elliptical,
2 in. long, and fairly intermediate in character between that of B. and
of C.
Potency oF PoLLEN or P. BUONAPARTEA.
There is good reason to believe, from the results of a few experiments
carried out several years ago, that the flowers of P. Buonapartea can be
fertilised by their own pollen; and evidence is not wanting that one
flower can be fertilised by the pollen of another.* Its potency has
been further made manifest, the flowers of the species P. alba having
been fertilised by it (p. 159). Moreover, experiments in progress point
to its being as potent as that of P. quadrangularis and P. alata in
fertilismg (imperfectly) its own hybrid offspring, P. alba x P. Buona-
partea (p. 163).
SEEDLINGS OF P. BuONAPARTEA.
On one occasion, as the result of accidental fertilisation, a fruit
was borne on my plant of P. Buonapartea. The fruit was oval, measur-
ing 43 in. long and 24 in. broad. Only thirty-four of the very numerous
seeds seemed good. ‘Twelve of the best were sown, and seven of them
germinated. Some of the seedlings were much more vigorous than
others, and very considerable diversity existed amongst them in leaf
form. One, at least, had distinctly narrower leaves. No opportunity,
however, was afforded of studying and comparing them in vigorous
development. Little more, therefore, could be gathered than that there
seemed to be a marked tendency in certain of the seedlings to produce
leaves of a form which perhaps was ancestral.
EXPERIMENTS IN CROSS-FERTILISATION.T
Many attempts have been made to fertilise the flowers of M.W. with
the pollen of other Passion-flowers. The following is an enumeration of
the resulting failures and partial successes :—
Passion-flowers supplying pollen Failure | Partial success
P. alata 8 0
P. alba 13 0
P. Buonapartea . 5 0
P. cerula . ; 4 12
P. Constance Elhot 12 5)
P. Decaisneana . 1 0
P. edulis ila 0
P. quadrangularis 2 0
P. suberosa : 2 0
Tacsonia Van Volxemi i132" 0
* Gardeners’ Chronicle, vol. xxiy. 1885, p. 181.
+ Cf. Darwin, Animals and Plants under Domestication, vol. ii. p. 137.
156 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
The pollen of P. cerulea (the male parent of the hybrid), and of its
variety, P. Constance Elliot, alone exercised sufficient potency to cause
swelling of the ovary. The maximum length of the fruit, due to fertili-
sation by pollen of P. cerulea, was 14 in., and the largest fruit by pollen
of P. Constance Elliot was 1,3, im. long and 4 in. at widest part, with
walls | in. thick. These dimensions were reached in a few days, and
they are far below what a fruit of the hybrid would attain to if fertilisation
were complete. In no case was any indication of development of the
ovules seen.
Some success with the pollen of P. Buonapartea (the seed parent of
the hybrid) might have been looked for.
Although the pollen of M.W. itself was obviously very abnormal, it
was thought desirable to experiment with it. Accordingly eight flowers
received pollen from their own anthers, and seven from the anthers of
other flowers of the same plant. As was to be expected, the result was a
negative one in every case.
While the failures above described are attributable for the most part
to causes not understood, one remarkable teratological feature, which is
Fies. 65, 66.—Ovartan Prourrication: f, Frraments ; p, Minrature Pistim
(both figs. x 2).
no doubt sufficient to constitute a barrier to successful fertilisation, has
been discovered.* The ovaries of certain flowers of the hybrid, displaying
no abnormal external features, have been found to enclose peculiar
structures. In some there arises from the base (fig. 65, /) a group of
minute filaments, commonly five in number, closely resembling in form
and bright coloration the outer coronal rays. When longer than the
cavity containing them, as they often are, the apical portions are curled
in irregularly. In other cases a miniature pistil (fig. 66, ») occupies the
same position, the characteristic colours being well developed. Occasion-
ally a few minute rays are found round the miniature gynophore.
Examples are met with in which these abnormal structures are repre-
sented by mere rudiments. The ovules in ovaries so invaded do not seem
to differ in any way from those in the more normal flowers.
The earliest flowers were most prone to ovarian prolification ; indeed,
it was almost universal at the beginning of the flowering season. In the
latest flowers the reverse condition was equally marked. As affording
* Vide Masters, op. cit. p. 181.
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 157
an indication of the state of mattersin mid-season, investigation of the
ovaries of fifteen flowers, on June 15, 1899, showed that six were normal,
three had rudimentary structures, two had blue filaments, and four had
miniature pistils; that is, nine exhibited prolification and six did not.
On June 28, eight flowers, and on July 7, eighteen flowers, were studied,
and all found to be normal; on July 8, however, twenty, and on Sept. 4,
sixteen, were examined, and of these one and two respectively were
abnormal.
The latter observations show that the abnormality may not entirely
disappear as the season advances. It is very obvious that the develop-
ment of the monstrosities described is intimately associated with the
vegetative vigour of the plant.
Opportunity was not afforded of noting their presence or absence in
the majority of the flowers experimented with; but looking to the fact
that after a certain date the flowers were mostly normal (that is, did not
show ovarian peculiarities), and taking into account a number of observa-
tions actually made on ovaries which failed to swell after pollination, it is
safe to surmise that fertilisation of the hybrid by any of the Passion-
flowers mentioned, except P. cerulea and P. Constance Elliot, is unlikely
to happen under any circumstances.
PASSIFLORA ALBA.
This species being a parent of the three hybrids yet to be described,
it is necessary to give a detailed account of its structure.
P. alba is an extremely rampant-growing species. The vegetative
organs present a characteristic light glaucous green colour.
The young stems and branches are cylindrical, very smooth, coated
with glaucous bloom, and either partially or quite filled with pure white
pith.
The stipules (fig. 68) are very large, examples 24 in. long and 1} in.
broad being met with. They are foliaceous, soft, obliquely lanceolate,
auricled, apiculate, recurved, with distinct mid-rib, but no radiating minor
veins. The apex bears a mucro |; in. long, terminated by a gland. The
auricles overlap and embrace the stem.
The leaf-stalks (fig. 71) are almost cylindrical towards the base,
and very slightly flattened in the distal part. They may in large
leaves attain the length of 31 in., or a little more. The glands are very
irregularly disposed. Four is the common number, and they are usually
placed in the basal half of the petiole, and well up on the upper side ;
seldom in opposite pairs, but most commonly alternating irregularly ;
often only three, occasionally six. The stalk of the gland is bluish,
curved, and about ,!, in. long; the gland green.
The leaf-blade is trilobed, the texture soft, thin, the largest measuring
6 in. long and 6} in. broad ; a good average size, however, is considerably
smaller. Single notches, sometimes two, with glands, occur between the
lobes a short distance from their base. The leaves when bruised emit a
very unpleasant odour.
The peduncle is 2 to 24 in. long; fine, cylindrical, thickening out-
158 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
wardly, often bending up suddenly at the outer end until at 90 degrees or
more to the general direction, thus bringing the flower into a more or
less erect position. The flowers are scentless. The bracts are ? in. long,
4 in. broad, cordate-lanceolate, auricled, with either one or two glandular
teeth at the base.
The sepals in the fully open flower (fig. 74) fall far back. They are
soft in texture, the upper side white, slightly tinged with light green, the
under side all green, or with one or both margins white; bearing scimitar-
shaped processes, arising ¢ in. from the end, the longest (4 to ,% in.),
occurring on the lowest sepals.
The petals are white, thin, 1 in. long, about } in. wide, greatly reclinate
in the open flower. In the corona the outer faucial rays (fig. 74, a) are in
two whorls, the external rays, about sixty-five in number, 3 in. long, pure
white and bent downwards; the internal rays, about 3 in. long, pure white,
capitate, also curving downwards, and often intermingling with the
external ones.
The second faucial series (fig. 74, 6) consists of two or three whorls
of extremely fine, white, capitate threads, ,°, in. long, the innermost
nearly erect, and the outer ones radiating outwards.
The inner or median series (fig. 74, c) forms a membranous funnel-
shaped tube narrowing upwards, the upper edge cut up into an irregular
white fringe, the minute clavate branches of which project inwards and
approach the fringed edge of the cupulate collar of the gonophore.
The incurved annular ridge in the tube of the flower is similar to
that already described in other Passion-flowers.
The gonophore is broad at the base, and a short distance up it bears
a fringed cupulate outgrowth which is divided into five parts by incisions
of the margin. The shaft above narrows gradually upwards, its colour
greenish-white.
The filaments are light green, the anthers } in. long, the pollen deep
yellow, very copious. .
The ovary is deep glaucous green, the styles light green, } in. long;
the stigmata very pale bluish-green.
All the earliest flowers to open in 1899, to the number of at least six,
on a strong plant, bore a four-rayed pistil. Afterwards the normal
three-rayed form appeared, and became gradually more numerously
represented than the former, as is shown in the subjoined table :—
| June 10th 12th | 13th | 16th 16th 17th| 19th) 2let 22nd 23rd Aug. 7th
Four-rayed pistils . | Ais) Ae OBO SABE RE LG Bo) Dace beg 8
Three-rayed pistils . | Set BAe libs eSyiedea, PAL 4 DS alk 24
Many flowers are self-fertilised. The stigmatic rays, erect in the bud,
become depressed in the open flower, and the side of one of the stigmata
comes in contact with the edge of the adjacent anther, and thus receives
pollen sufficient to effect complete fertilisation. When there are four rays,
two of them occasionally receive pollen in this way. On August 8, 1899,
thirty-eight self-set fruits of all sizes were counted on one large plant.
Pollen of one flower when applied to another is also quite effectual.
The fruit ripens in ten to twelve weeks after fertilisation. Good
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 159
examples measure 2! to 2,*, in. long. They are light yellowish-green, and
rather pleasantly scented. The outer wall, beneath the somewhat tough,
green, easily separable skin, is } to } in. thick, and is white, soft, and
spongy. From it pass numerous soft threads, once or twice branched,
connecting the outer wall with the thin membranous sae which bears the
placentas internally. The greatest numbers of seeds found were 258 and
232, the former in a fruit resulting from fertilisation by pollen of another
flower of the same plant, and the latter in a self-set fruit. The seeds are
elliptical, ,3, in. long, black, and obscurely pitted. The viscid yellowish
fluid which accompanies them is bitter and unpleasant to the taste, and
gives a disagreeable odour to the fruit when it is opened.
Comparatively few experiments in cross-fertilising this species have
been carried out. Success followed pollination by P. Buonapartea and
P. edulis respectively (infra, p. 165). The application of pollen of P. Con-
stance Elliot has led to variable results. As an outcome of experiments
in 1896, the fruit in one case developed fairly well, and bore numerous
immature seeds ; in another, a somewhat nearer approach tu success was
reached ; in a third, a fully developed fruit was obtained, containing 180
seeds of all sizes, but only three or four appeared to be normal. A fourth
swelled rapidly, and promised well, but was accidentally broken off when
nine days old.
During the present season (1899) a good fruit was obtained by the
same cross. It contained 200 seeds, all more or less badly developed,
except one which alone was embedded in yellow fluid, and possessed the
very deep brown colour characteristic of a healthy condition. All the seeds
were sown, but only one—the good one—has germinated. The seedling,
still young, appears to have a vigorous constitution. It bears a close
resemblance to the plants of the reciprocal cross, P. Constance Elliot x
P. alba (p. 166) when these were of corresponding age. tis interesting
to note that the pistil of the flower fertilised was four-rayed, and that the
fruit secured possessed four, instead of three, placentas.
The additional organs are doubtless due to the splitting of one of
the normal three. The numbers of seeds borne by the four placentas
of a self-set fruit of P. alba bear out this hypothesis, these being 65, 76,
22,39. The total of the two latter numbers represents a good average
number for one placenta.
The application of the pollen of Tacsonia Van Volxemi unexpectedly
caused the ovary to ewell to a length of 2 in., but no further develop-
ment ensued.
No swelling took place when pollen of the following Passion-flowers
was used: P. Decaisneana (4 experiments), P. suberosa (2), and P.
Watsoniana (2).
PASSIFLORA ALBA x P. BUONAPARTEA.
An experiment in crossing P. alba by P. Buonapartea, carried out in
June 1896, proved successful. The fruit ten weeks after fertilisation was
so ripe that a very light touch caused it to fall. It was of good size,
and in general structure did not differ from the fruit of P. alba, as
described above. The placentas bore respectively 24, 24, and 25 good
160 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY,
seeds, and 3, 6, and 4 poorly developed ones, the total number being 86.
The good seeds were dark purplish, almost black, pitted, } in. long
Sixty-seven were sown, and 21 germinated.
Great variation was observable in the seedlings, in respect of habit
and vigour. One of them was from the first much stronger than the
others. All were characterised by having a more or less marked tendency
to develop yellow variegation in the leaves. Several had very delicate
stems, and a number succumbed during the first winter, leaving three or
four of sufficient vigour to justify their being planted out in a greenhouse.
In that position they at first made good growth, but one after another
died before reaching the flowering stage, until the robust one, referred to
Fie. 67.—Passrrtora Sr. Ruie (nat. size).
above, alone was left. Unfortunately, very few notes were kept of those
that died. They differed very materially among themselves in regard to
the size of their leaves. With one exception, they resembled the surviv-
ing plant in the leaves being three-lobed. In the exceptional case
elliptical leaves alone were produced, but ‘perhaps this may have been
due to the retention for a longer period than usual of a form very com-
monly found in Passion-flower seedlings. In one of the seedlings the
yellow variegation was very ornamental.
PASSIFLORA ST. RULE.
The last survivor, now named P. St. Rule, is a very strong-growing
plant, with rather loose branching habit and extremely luxuriant foliage.
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 161
The young stems and branches are five-angled, one of the angles
being more obtuse than the others. The younger branches are full of
pure-white pith, or more or less hollow; slightly glaucous, the side
exposed to the sun often reddish.
The stipules (fig. 69) are obliquely lanceolate, apiculate, serrate on
the longer side, the teeth distinctly glandular; the largest 1,); in. long,
and ,°- in. wide.
The leaf-stalk (fig. 72) is 14 to 3 in. long, nearly cylindrical, flat on the
top, the ridges obscure. The petiolar glands are large, sessile, grey, very
often five in number, irregularly distributed, pretty often two of them
being paired. Four or six glands are of fairly common occurrence, the
former being often in pairs—one pair above and the other beneath the
middle of the petiole.
The leaf-blades are always tri-lobed, the largest example 6 in. long
and 7 in. wide, bright green above, light bluish-green underneath ; the
JHW
Fic. 68.—P. auBa. Fic. 69.—P. Sr. Rute. Fic. 70.—P. BuonaPaRTEA.
SrreuLeEs (nat. size).
middle lobe with usually one, sometimes two, obscure notches } to 4 in.
from the base.
The peduncle is 1 in. long, sub-cylindrical, curved upwards a little,
and so directed as commonly to bring the face of the flower into a vertical
position, or give it a slight tilt upwards.
The bracts are + to 1 in. long, 3 to # in. wide; ovate-cordate, serrate,
with actively secreting glandular teeth.
The flowers are as a rule produced singly on individual branches,
but very often in pairs, one in each of two neighbouring nodes. They
are (figs. 67 and 75) 3 in. in diameter, exclusive of the aristz of the
sepals. The odour is Ivis-like, faint and pleasant, resembling that of
P. Margaret Wilson.
The sepals are 13 in. long, ,’5 in. broad at base ; in fully open flowers
bent back 25° to 30° below the horizontal, and causing the bracts to be
folded back above the middle ; thick, with spongy texture, the lower side
M
162 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Fic. 71.—Lear or P.
ALBA (x 4).
Fic. 72.—Lear or P. Sr. Ruue (x 4):
Fic. 73.—Lear or P. Buonapartea (x 3).
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 163
bright green or with one or both margins lilac-rose-coloured, according
to position in bud, the upper side light lilac-rose ; the faleate process of
the lowest sepal 2 in. long, that of the highest ¢ in.
The petals are 1} in. long, 4 in. broad, narrow and white at the base,
delicate rose-purple above, paler beneath ; reflexed 15° to 20° beneath the
horizontal plane.
The outer coronal rays (fig. 75, a) are in two whorls, directed 10° to 20°
above the horizontal, with an expansion of 24 in.; commonly seventy-
three in number (outer thirty-eight, inner thirty-five), the rays in both
whorls 1 in. long, almost straight, with the apical portion (} to ;°; in.)
flexuous ; the basal 1 in. white, succeeded in the inner rays by three,
and in the outer by four, purple bands alternating with white; the outer
half-length bright mauve, tipped with white.
The second series (fig. 75, b) is in three (in some cases reduced to two)
whorls, the external rays } in. long, rising close to the base of the inner
rays of the outer series, and lying nearly parallel with them ; the internal
rays } in. long, almost erect, or leaning towards the gonophore.
The median series (fig. 75, c) forms a white, tent-like roof to the
nectary, the upper part in close proximity to the gonophore, and bending
upwards as a fringe composed of forked, somewhat clavate, filaments,
4's in. long, dotted with light purple. Very short purple-spotted knobs
rise in a circle on the inside of the bend, and lie in contact with the
ledge of the gonophore. The annular ridge is usually very slightly
incurved, the nectar plentiful.
The gonophore is cylindrical in the lower portion, and at } in. from
the base bears a small ledge which is either cupulate or sinuous. The
shaft above is rather slender, the lower portion white, the upper portion
green with very faint purple spots.
The filaments are dull green, faintly spotted with purple on both sides.
The anthers are invariably abnormal, hanging vertically, fleshy, indehiscent,
and colourless, except for a little yellow colour shining through the trans-
parent walls and indicating the presence of a little very poorly developed
pollen.
The ovary is light green, relatively large and thick-walled ; the styles
4 in. long, massive, straight, very pale green with dull purple at the
base ; the stigmata large, light green. No abnormality of the ovary has
ever been observed.
The following experiments in pollinating P. St. Rule have been carried
out :—
Passion-flowers supplying pollen Failure Partial success
P. alata .
P. alba
P. Buonapartea
P. cxerulea ; :
P. Constance Elliot
P. edulis. :
P. Decaisneana :
P. Impératrice Eugénie .
P. quadrangularis .
P. suberosa
P. Watsoniana F
Tacsonia Van Volxemi .
_
CCOOCOWNWOCRF OU Ut ©
—
Cr NORRF RF OOeFN ©
Kg
to
164 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Fic 74.—Secrion or Fiower or P. apa (nat. size).
Fic. 75.—Secrion or Fiower or P. Sr. Rune (nat. size).
fj)
yf
iif
Yh
Ly
YJ
Pp
Fic. 76.—Section or Firowrer or P. Buonavartrua (nat. size).
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 165
It is not a little surprising to find so great a measure of success as
is set forth in the above table. The most noteworthy results were
secured by the use of pollen of P. alata. The ten fruits swelled rapidly,
several attaining the length of 14 in. within six days, and 2% in. within
thirteen days. The smallest fruit collapsed on the fourteenth day, when
1% in. long. It contained three seeds, arrested in process of development.
The next in point of size, 2} in. long, failed on the nineteenth day. The
remaining fruits are larger, and give promise of yielding better seed.
The two largest measure respectively, at the moment of writing, 22 in.
and 2% in. in length. Externally they present unmistakable blending of
the characters of the fruits of the parents, P. alba and P. Buonapartea.
The internal structure, seen in the examples which have swelled to some
size before falling, also bears this out, the characters of P. alba being
perhaps rather the more evident.*
The two fruits resulting from pollination by P. quadrangularis
reached the length of 2 in. before falling. They contained a few seeds
which had developed a little.
The fruits due to fertilisation by pollen of P. Buonapartea are still
young. The failure recorded may well have been due to the pollen
having been kept four or five days.T
The partial success by pollen of P. Decaisneana (P. alata x
P. quadrangularis) was represented by a fruit which fell when } in.
long.
Of the three fruits due to fertilisation by P. alba, the largest
measured 23 in. long, and contained when it fell, four weeks old, the
remains of seven poorly developed seeds. The second fruit was 2 in.
in length when it fell, and the third fell early.
The largest fruit resulting from the application of the pollen of
P. cerulea measured 2} in. in length, and contained four half-developed
seeds. The best example obtained, by pollen of P. Constance Elliot,
reached a very considerable size, being 22? in. in length, and well
formed. It was, however, quite empty. Another, 2 in. in length,
contained four young seeds.
=)
PASSIFLORA ALBA x P. EDULIS.
This hybrid was secured by an experiment carried out on Sep-
tember 1, 1898. The fully ripe fruit fell when lightly touched, on
February 4, 1899, after having hung for a considerable time during the
winter without showing signs of complete ripeness. It bore all the
characters of a well-developed fruit of P. alba fertilised by its own
pollen. It was 22 in. long, and contained 238 seeds, which were
* Opportunity has been afforded of making a few further observations on the
fruits resulting from fertilisation by P. alata. Three of these were found hanging
fourteen weeks after pollination. They presented a deceptively fresh appearance,
being green and only slightly shrivelled. The largest measured 3 in. in length.
When opened they were all found to contain nothing except flat, dry, brownish rudi-
ments of seeds, borne for the most part in the apical half of the ovary. The total
numbers of these in the fruits were respectively seventy-four, sixty-three, and fifty-one.
+ A fruit of this series was also found to have hung fourteen weeks in a fairly
fresh state. It measured 3 in. in length, and contained twenty-four rudimentary
seeds. No good seed has been produced in any of the fruits borne by P. St. Rule.
166 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
evidently all good. On February 7, 210 of these were sown. Their
germination was very slow and unequal, there. being a considerable
interval of time between the appearance of the first and the last of
sixteen seedlings now above ground. The first to germinate died very
soon, but another took the lead and grew far ahead of the rest, being at
the time of writing 12 in. in height, with fifteen leaves, while the others
vary from 4 in. to } in. in height, with only a few young leaves.
The strongest plant is still too young to admit of comparative descrip-
tion. The leaves, with the exception of two young oval ones, are three-
lobed, a form which seems likely to persist. As a rule two glands occur
close together, a little above the mid-length of the petiole. In P. edulis
the leaves are three-lobed, with a pair of petiolar glands close to the leaf
_ blade.
Much golden variegation existed in the earlier leaves of this seedling,
and is a striking feature in all the other seedlings. It may be recalled
(p. 160) that this condition, indicating constitutional weakness, obtained
in the hybrids of which P. St. Rule is the survivor, and which also had
P. alba as their seed parent.
PASSIFLORA CONSTANCE ELLIOT x P. ALBA.
This cross was effected in the beginning of September 1898, and the
ripe fruit was gathered in the end of November. The fruit was oval,
13 in. long, orange in colour, and full of deep-red pulp. The good seeds,
189 in number, were ; to ;°; in. long, black, and pitted. Besides these,
forty undeveloped ones were counted. On February 1, 1899, 170 seeds
were sown, and in six weeks it was found that 144 had germinated.
The seedlings bore a most marked resemblance to each other; and in
the limited number kept for cultivation the similarity continues to be so
great as to defy distinction. ‘They have made very vigorous growth, but
it is hardly to be expected that they will flower this season.
The great majority of the very earliest leaves presented a three-lobed
form. The adult form, having narrower lobes, was reached at about the
twelfth leaf. Very soon five-lobed leaves appeared in an irregular fashion
among the three-lobed ones ; and at the present time it is impossible to
say which form will ultimately predominate. The former are derived
from the latter by the lobing of the margin, and by the radiating veins,
seen near the lower edge of the lateral lobes, becoming the mid-veins
of the new lobes. Asymmetrical transition forms with four lobes occur
here and there.
The largest leaves at present are three-lobed ones (fig. 77). The
petiole is cylindrical, 1} to 13 in. long, most commonly bearing one pair
of stalked glands close together near its mid-length. The stalks of the
glands measure |, in. in length. Three glands are often present, some-
times four. The blade of the leaf is 2} to 3,°, in. long and 3} to 43 in.
broad. Three conspicuous glands on short pedicels, directed backward,
occur on each side of the middle lobe near its base, and two glands of a
similar kind occur on the lateral lobes, and correspond in position to the
lower two on the middle lobe. Other marginal glands in the leaves of
this hybrid (as in other Passion-flowers) are indicated by the presence
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 167
of secretion, the organs themselves being often difficult to detect by the
naked eye.
The stipules resemble those of the female parent considerably, but are
not so markedly one-sided, and the apical point is not nearly so long.
On the whole, the characters of the hybrid, as represented by the
vegetative organs, have a greater leaning to that parent than to the
other, P. alba.
For purposes of comparison it should be stated that the plant of
Fic. 77.—Turee-Losep Lear or P. Constance Exuior x P. anpa (nat. size)
P. Constance Elliot, used as the seed parent, bears a very much larger
proportion of seven-lobed leaves than is borne on the plants of
P. cerulea grown at St. Andrews, and the lobes are distinctly
narrower. The additional lobes, however, are to be regarded simply
as outgrowths or branches of the two lowest of the five lobes in the more
typical leaf.
168 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
RIBES NIGRUM x R. GROSSULARIA.
(Ribes nigro-grossularia.)
At one time it was thought impossible to effect a cross between the
Black Currant and Gooseberry. This has, however, been done by at
least three hybridists. The first to succeed was probably C. J. Burnett,
Esq., Old Aberdeen. This skilful experimenter informs me that more
than twenty years ago he had proceeded so far as to have a number of
young crossed seedlings growing in his garden; but the hoe, used indis-
criminately, closed their career before they had developed their distinctive
characters. Ten or twelve yearsago Mr. Burnett renewed his efforts, and
secured several undoubted hybrids, three of which are still grown by him.
In the former as well as in the latter series the Black Currant was the
seed parent.
Very shortly after Mr. Burnett’s first experiments, Mr. W. Culverwell,
Thorpe Perrow, Bedale, about 1880, carried out the same cross. Mr.
Culverwell tells me that only one plant resulted from his first efforts,
and that it “flowered the second year, but never fruited.” He crossed
again, using the ‘Whitesmith’ Gooseberry as the pollen parent, and
eight plants were obtained. The earliest reference to the plants
is the raiser’s letter to the Gardeners’ Chronicle, vol. xix. n.s. 1883,
p. 685. Referring to the example sent with the communication, pre-
sumably the unique plant of the first cross referred to above, the observa-
tion is made that it flowered profusely but did not set fruit. There were
no spines; and while the wood was like that of the Black Currant (the
seed parent), the plant had not the smell of the Currant. Mention is also
made of the eight plants “ from a recent cross,’ two of which had the
smell of the Black Currant. These were at that period, however, too
young to show flower.
In Dr. J. M. Macfarlane’s paper on the ‘“‘ Minute Structure of Plant
Hybrids,” read May, June, 1891, and published in Vrans. Roy. Soc.
Edin., vol. xxxvii., one of Mr. Culyerwell’s plants receives special atten-
tion. The author found that differences “in leaf form, time of defolia-
tion and habit” existed in the seedlings ; and he selected one for detailed
examination, which appeared to be “most nearly intermediate between
the parents,” and left “‘ others which inclined to the Black Currant’’ to
be dealt with at a future time.
In August 1892 Mr. Culverwell had the satisfaction of finding fruit
for the first time. He announced this important event in the Gardeners’
Chromcle, vol. xii. 3rd ser. 1892, p. 161, and in the same volume
(pp. 271, 277) a figure and a description of the fruit are given.
Mention is made of the chief points of comparative importance be-
tween the hybrid and its parents, in respect of their habit, the nature of
the wood, and the character of the leaf. The fruit is described as ‘ of
the size of Black Currants, but in colour like a red Gooseberry, beset with
fine hairs, and destitute of seeds. The flavour partook of that of the
Gooseberry mixed with that of the Black Currant.”
As far as I can gather, the specimen referred to is the only one of the
set which has fruited, and it is no doubt the same as. that described by
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 169
Dr. Macfarlane (without fruit), as the most distinctly intermediate. Mr.
Culverwell, in Gardeners’ Chronicle, vol. xii. p. 346, mentions that this
plant possesses ‘‘not a particle of scent like the Black Currant,” and,
further, that “the Gooseberry caterpillar is particularly fond of the
hybrid, whereas it will not touch the Black Currant.”
Five years ago I succeeded at St. Andrews in repeating the same
cross, and my stock consists of three indubitable hybrids. Besides these,
however, there appeared a number of plants of pure Black Currant; the
latter vary among themselves a little, but are no doubt the result of
accidental self-pollination. Such an accident is not altogether easy to
avoid in experimenting with the Black Currant. I understand that Mr.
Burnett weeded out some plants from his crossed stock, because he re-
garded them as Black Currant seedlings ; and the reference made by Mr.
Fic. 78.-_FLowERING-sHoor or R. nicRuM x R. Grossunarta, B (nat. size).
Culverwell (above quoted) to two of his seedlings possessing the Black
Currant odour seems to point to a similar accident having befallen him
in his experiments, although the incident may now be forgotten.
I was unfortunately unable to take note of the names of the varieties
I operated with, or the number of fruits set and seeds sown. The three
hybrids (A, B, C) proclaim their authenticity unmistakably in the form of
their foliage. Two of them (A, B) flowered for the first time last year
(1898) ; the third (C), which has not flowered yet, is not so robust.
With different treatment they might have been brought into flower at an
earlier age. The stronger two are not quite similar, the one (A) being of
taller habit, rather less floriferous, and with flowers rather larger than the
other (B) (fig. 78). All three bear a marked general resemblance to
Mr. Culverwell’s best known form, but are distinguishable from it
170 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
in minor points in leaf and flower. Spines are entirely absent in Mr.
Burnett’s, Mr. Culverwell’s, and my own hybrids. «
In comparing the hybrids with their parents it has to be kept in mind
that, while there is but little structural difference in varieties of Black
Currant, much more exists in varieties of Gooseberry, both in flower
and foliage. As already stated I cannot now identify the Gooseberry
parent of my hybrids, and I am accordingly unable to make definite
statements as to the origin of peculiarities exhibited by them.
While the size and the shade of colour of Gooseberry leaves may vary,
the form is almost always the same, a marked characteristic being the
non-cordate base. In Mr. Culverwell’s plant there is a closer approach
in leaf form to the Gooseberry than obtains in my plants, the leaves of
the latter (A, fig. 81; C, fig. 82) being more distinctly cordate. No Black
Fic. 79 (30).—Buackx Currant. Fria. 80 (31).—Goosrperry. Fic. 81 (32).—Hyepri, A.
Fie. 82 (33).—Hysrip, C.
Leaves (nat. size).
Currant odour is emitted when the leaves of my hybrids are bruised, and,
as in Mr. Culverwell’s case, the Gooseberry caterpillar finds them specially
palatable.
A few irregularly scattered, colourless, stalked glands are found on the
under side of the leaves of my plants and Mr. Culverwell’s also. The
head is multicellular, much flattened, ‘1 mm. in diameter, and the stalk
is very short, and is not more than ‘03 mm. in diameter. It seems certain
that these glands disappear for the most part as the leaf attains maturity.
No quite sessile ones, reproducing the form of those in the Black Currant,
were met with. lam accordingly led to dissent from Dr. Macfarlane’s
opinion (loc. cit. p. 274) that any reproduction of the sessile glands of
Fi. mgrum is found to occur in the hybrid.
THE STRUCTURE OF CERTAIN NEW HYBRIDS. VFI
The number of flowers in the inflorescence of the Black Currant may
occasionally be as high as thirteen, but a very common number is either
seven or eight. In the Gooseberry two is the maximum, and very often
there is only one. In my hybrids the inflorescence most commonly bears
three flowers pretty close together. The length of the inflorescence is 1 to
1} in., or at most 15 in. Very often there are four flowers, three of which
are grouped together terminally, and the fourth borne on a rather long
pedicel which arises from the very base of the inflorescence. This basal
flower is often later in opening than one or more of the others. Occasion-
ally there are two or even three flowers borne on a common rachis, in
place of one basal flower. The greatest number of flowers hitherto
observed on any spur is thus five or six; but the usual number, as
already mentioned, is either three or four. The peculiar position of the
basal flower and the retardation of its opening are features frequently
exemplified in the Black Currant and inherited from it.
The hybrids are decidedly later than the Gooseberries in commencing
to flower, and are in full blossom when the latter have almost passed out
of flower and are bearing fruit of considerable size. On the other hand,
while one or two of the hybrid flowers may be open before any of the
Black Currant ones, they may be regarded as contemporaneous with
them.
In the Black Currant flower the bright yellow scent-secreting glands
are very characteristic structures. ‘They number from fifty to eighty, or
even more, and are scattered irregularly over the surface of the ovary
and the calycine cup as well. They are quite sessile (fig. 83), and very
often placed at the bottom of a shallow depression. Their diameter is very
uniform, being ‘15mm. to‘17mm. A number of smaller ones, however,
may be found. Their structure has been described by several botanists.
The gland is multicellular, and the cuticle is commonly found raised by
the yellow secretion which accumulates beneath it.
In the Gooseberry we find greater diversity in respect of gland-
bearing in the flower. In some varieties the ovary is tomentose and
thickly studded with long-stalked red glands (fig. 85). In others, the
numerous glands are colourless, or almost colourless. Further, varieties
are met with in which the ovary is densely clothed with soft white hairs,
amongst which occur a few irregularly scattered long-stalked red glands ;
while others, still tomentose, are absolutely destitute of glands. Finally,
glands may be quite absent, and the ovary be almost or altogether
destitute of hairs as well. When hairs are present they also clothe, but
less densely, the calycine cup. Glands, however, never occur on the cup.
The glands may have a diameter of ‘1 mm., and the stalks attain the length
of 1°2mm. The red colour often extends some distance down the stalk.
In the ‘ Whitesmith ’ Gooseberry, the pollen parent of Mr. Culverwell’s
hybrids, the ovary (in the specimens examined by me) was tomentose,
with a few red glands borne on long stalks. They numbered from four
or five to twenty-four, at most, in the plant studied. The stalk was
usually 1 mm. in length, and the red colour of the glands extended a
little distance downwards. The average diameter of the glands was
‘14 mm., the largest being 16mm. The stigma stood only a little above
the anthers, and the pollen was very good.
JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
172
ye
Fic. 83.—Porrion oF Ovartan Watt or Brack Currant, IN TRANSVERSE SECTION
(magnified
Fic. 84.—Porrion or Ovarian Wati or Hyprip (magnified).
Ye Ft
Porrion of OvarIAN WALL oF GoosrBERRY (magnified).
Fic. 85.
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 173
It is interesting to find that in Mr. Culverwell’s hybrid short-stalked
glands occur on the ovary and on the lower part of the calycine cup
also. They are never quite sessile, and are large enough to be easily
seen by the aid of a hand lens. Their stalks are relatively delicate, and
vary in length from ‘03mm. to 06mm. The diameter of the gland is
commonly from ‘1 mm.to’12 mm. Very often the glands are bright red, but
commonly enough they are colourless. At least as many as twenty-four
red glands may be found in one flower, besides numerous colourless ones.
All gradational stages, from the claret-coloured to the colourless, occur.
Sometimes the coloured ones are found on one side of the ovary, and the
colourless ones on the other. I have not noticed any sessile yellow
glands, and I am therefore unable to corroborate Dr. Macfarlane’s state-
ment (loc. cit. p. 281) that “four types’”’ of ‘“ hairs,’ including sessile
glands, are present on the ovarian surface of this hybrid.
The bright-red coloured glands, above described, may with consider-
able assurance be regarded as identical in structure and function with
those in the Gooseberry, and there seems no good reason to suppose that
the absence of colour in the others constitutes a material difference.
Fic. 86.—Buack Currant. Fic. 87.—Hysrip. Fic. 88.—GoosEBERRY.
FLowers tN Section (x 2).
Stalked glands of the same size as those in Mr. Culverwell’s hybrid, and
occupying a similar position, occur in the flowers of my two hybrids
(fig. 84). The diameter of the glands is ‘1mm. to’13mm., and the length
of stalk ‘03 mm. to'13 mm. _ I have, however, never seen any of them
red-coloured; and I am accordingly inclined to believe that a variety
of Gooseberry with little or no colour in the glands may have been the
parent of my plants.
If the bisected flowers of my hybrids and their parents be compared
(figs. 86, 87, 88), many features showing a blending of the parental
characters will be observable. The ovary is nearly intermediate in size.
The style arises from an almost flat surface in the Gooseberry, and from
a greatly arched surface in the Black Currant. It is raised on a slight
elevation in the hybrids.
The style in the Black Currant (fig. 86) is solid and glabrous, and
the stigma inconspicuously bifid. In the Gooseberry (fig. 88) the style
is cleft almost to the base, and is clothed with hairs which radiate
horizontally, the longest being at the level of the throat of the flower.
In the hybrids (fig. 87) the style is cleft nearly midway, and bears hairs
which are much fewer in number and shorter than those of the cor-
responding organ of the Gooseberry.
174 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
The interior of the cup in the Black Currant is destitute of hairs ;
in the Gooseberry hairs similar to those on the style project inwards
from the base of the petals and filaments, and are long enough to meet
the hairs of the style. Im the hybrids only a few short hairs occur in
this position, or they may be altogether absent.
There is much red coloration in the upper side of the sepals in the
hybrids, the colour being developed chiefly at the base and margins.
Very often short fine hairs are present on the upper side of the distal
half of the sepals. The petals are white, and are less distinctly spathulate
than in the Gooseberry.
Th? filaments are markedly adherent in the Black Currant, non-
adherent in the Gooseberry, and slightly adherent in the hybrids. The
anthers of the hybrids are of good size, but the pollen is deficient in
quantity and highly abnormal. In a microscopic examination of it, one
scarcely finds a single grain with any appearance of soundness, a condition
of affairs met with also in Mr. Culverwell’s hybrid.
My plants are visited freely by humble and hive bees, and would
inevitably be fertilised if the pollen were good. Perforation of the side
of the flower of Mr. Culverwell’s hybrid by bees is a not uncommon
occurrence, and the aperture thus formed may sometimes be so enlarged
by repeated visits as to become confluent with the mouth of the flower.
I have not noticed any of the flowers of my hybrids similarly pierced.
In one of my hybrids (B, fig. 87), as in Mr. Culverwell’s best known
plant, the stigma protrudes so far beyond the stamens as ordinarily to
escape self-pollination ; but in the other (A) a good many of the flowers
have styles so shortened that the apices of the anthers are in very close
proximity to the stigma, and self-pollination might take place, especially
when the flowers have faded a little.
Mr. Culverwell informs me that all he does to assist in the fertilisa-
tion of his plants is to shake the bushes when the atmosphere is a little
damp. It is very likely that a drop of water might suffice to convey the
pollen to the stigma hanging below the anthers, and shaking, or the
action of the wind, might also help; but the difficulty encountered after
all is the probability of the pollen being impotent. On the other hand,
itis highly probable that many of the flowers are pollinated by bees
which have come direct either from Gooseberry or Black Currant bushes.
My plants grow beside Black Currants, and I have observed bees passing
from the latter to the former, and vice versa. If Gooseberry bushes had
been near by, a similar transference of pollen between them and the
hybrids would certainly have taken place.
Mr. Culverwell kindly sent me some shoots in fruit last year. I
understand that as many as four fruits may be carried by a single spur.
Two is a common number. The fruits are slightly bigger than a large
Black Currant, often flattened considerably, and in colour, as already
noted, resembling a dark red Gooseberry. The flavour is that of the
Gooseberry, decidedly and very palatably mingled with that of the Black
Currant. It is interesting to find that the somewhat thin and rather
tough skin, if pressed on white paper, leaves a pink stain, whereas the
Black Currant leaves a purple stain, and the Gooseberry none at all.
All the fruits examined by me, numbering twelve or more, like those
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 175
previously examined by others, were absolutely seedless, a few minute
scales at best being present in place of seeds.
During the present summer (1899) I endeavoured to fertilise the
flowers of my hybrids, using a variety of pollen as follows: 44 flowers
received pollen from the Gooseberry (7 different kinds); 19 from the
Black Currant, and 16 from Ribes divaricatum. Further, in 7 cases,
pollen (such as it was) was taken from other flowers of the same hybrid,
and in five cases it was taken from one hybrid to the other. As an out-
come of the 72 attempts enumerated, one berry has been secured, and it
has been due to the application of the pollen of R. divaricatum.
This fruit ripened and fell, when lightly shaken, fifteen weeks after
fertilisation. It was 43, in. in length, of oval outline, but asymmetrical;
the remains of the perianth forming an appendage } in. long ; the skin
red like a red Gooseberry, sparsely clothed with very fine white hairs,
amongst which occurred 20 to 30 stalked glands. The latter could be
readily seen with a lens magnifying a few diameters, and were just visible
to the naked eye when placed against a suitable background. The pulp
was palatable. No seeds were present.
This remarkable result naturally leads to the suggestion that as a
practical matter certain species or varieties of ibes might with advantage
be planted in the vicinity of the hybrids, so as to help in the setting of
fruit.
It should be remembered that my two flower-bearing plants have not
been propagated. Itisnot improbable that cuttings might have a stronger
tendency to fruit. Budding on other kinds of Ribes, or even transplanta-
tion into other soil, might have the desired effect.
An examination of the ovules of my hybrids, and of Mr. Culverwell’s
also, by hand sections, did not disclose any abnormal features; but
further investigation, including the styles as well as the ovaries, is needed
before a satisfactory explanation of the partial or complete sterility can
be attempted.
It is evident from information most obligingly supplied me by Mr.
Burnett, and from examination of material sent, that his hybrids bear a
very close general resemblance to mine in all respects. I found, how-
ever, that the younger leaves studied bear a far greater number of
minute, colourless, very short-stalked glands than do any of the plants
above described. They are dotted over the whole under side of the leaf
blade, to all appearance almost, if not quite, as thickly as the sessile
yellow glands are in the Black Currant. They appear as minute white
dots under the hand lens, and are rather less than half the average
diameter of the Black Currant glands.
In the flowers studied the pedicel, ovary, and calycine cup are virtually
glabrous, only a very few minute hairs being present. Minute almost
sessile colourless glands like those in the hybrids already described, and
‘08 mm. in diameter, occur on the ovary. They are so few as to be easily
overlooked altogether. One was observed to have a very little red
coloration. The petals are wider than in my plants, and overlap con-
siderably. The style rises from a distinctly arched base. The hairs on
the style and in the throat of the flower resemble those in my hybrids,
and the stigma projects some distance, as in one of my plants (B). The
176 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
anthers having been lost in transit, no opportunity of studying the
pollen of Mr. Burnett’s plant was afforded. .
BEGONIAS (TUBEROUS VARIETIES) x B. COCCINEA.
The so-called Tuberous Begonias, as is well known, have a rather
complex pedigree. In spite of this, they are wonderfully fertile, large
capsules of good seed being very readily obtained when certain strains
are desired. It did not, however, seem at all likely that the pollen of a
species so essentially different from the Tuberous Begonias as B. coccinea
is would serve to fertilise their flowers, and yet it has proved potent to a
very marked degree. Experiments resulted in fine capsules being formed,
and the seed sown produced very numerous seedlings of most vigorous
character. The very first leaves of the seedlings displayed a feature of
much interest, the upper surface being dotted with silvery spots. As
growth proceeded, there was no disappearance of this character, all the
leaves of all the specimens during the vegetative period of the first
season being more or less distinctly spotted. There was very consider-
able diversity in respect of the number and size of the spots, these being
in some cases of fair size and relatively few in number, in others
minute and in great numbers. The under surface was commonly red,
often a fine deep red, and always quite destitute of spots. The shape of
the leaves betokened the influence of both parents.
Singularly striking variation was exhibited in the mode of growth of
the stems and branches, affording a rather bewildering field of observa-
tion. Examples, for instance, occurred having a single stem which grew
straight up to the length of 12 to 14 in., and developed a spherical swelling
at its base; others had single but branching stems; others again had
one or more shorter or longer, branched or unbranched, stems springing
from a semi-tuberous base (fig. 89) and so forth.
At the resting period further study disclosed very many grades
between the ideal ‘‘tuberous’’ and “non-tuberous ”’ conditions, neither
extreme, however, being represented. It was of unusual interest to note
the results of the ripening process, some or many of the joints, or even
entire branches, falling off naturally, and leaving the plants ultimately
with a broken and abbreviated appearance. (Fig. 90.)
In spring the bursting of the more vigorous buds here and there on
the branches, stems, or swollen bases served further to emphasise the
peculiar conditions which the ebbing of the vitality, so to speak, had
- occasioned in autumn. (Tig. 91.)
The somewhat nondescript perennating structures were rather difficult
to winter successfully, and it is probable that a certain amount of drying-
off given to these may have proved severe, for the plants thus treated
have not grown so freely as might have been expected, nor have any of
them flowered yet.
A new series with similar parentage, sown this season, is showing a
striking difference from the above, inasmuch as although the young
leaves were similarly spotted, the spots have tended to disappear in the
older leaves. Up to the present the resemblance to the pollen parent,
Fic. 89.—Rep Tuserous Beconta x B. coccINEA—THE TOP LEAVES CUT AWAY
nat. size).
N
178 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
B. coccinea, is greater in the new series than in that above
described. .
Seeing that no spots occur in the adult leayes of the parents, it was
at first puzzling to account for their presence in the hybrids. The
solution of the problem was, of course, to be looked for by studying the
young leaves of the parents, arising either from the seed or the bud, or
both. I am nof aware that the seedlings of Tuberous Begonias ever
exhibit the peculiarity in question, and I have not yet had opportunity of
observing seedlings of B. coccinea. In the latter, as grown from cuttings,
one seldom sees any spots, but now and then a young shoot is found
bearing quite distinctly spotted leaves. In the meantime, therefore, one
aA
Fic. 90.—Rep Tusrrous Breconta x B. coccinna; a, b,c FauuEN Jornrs (nat. size).
can only surmise that a character usually latent in one of the parents finds
scope for fuller expression in the hybrid offspring. _
In the second series, the general habit of the plants and the form of
the leaves clearly point to B. coccinea being rather more potent than
before; and the partial disappearance of the spots at an early stage
suggests that, while in the hybrids of the previous year an early phase of
vegetative life of the male parent was impressed on the offspring, in the °
newer hybrids a more mature condition is represented.
On the other hand, it must not be forgotten that the female parents
come of a very variable stock. Those used in the second set of experi-
ments were a newer and somewhat finer class of Tuberous Begonias.
A singular corroboration of the view that it is to the action of the
pollen parent, B. coccinea, that the spots are due, has been afforded by
seedlings of B. hydrocotylifolia x B. coccinea, raised during the present
THE STRUCTURE OF CERTAIN NEW HYBRIDS. 179
season (1899). In these the leaves, some of which are 3% in. long at the
time of writing, are all beautifully marked with silvery spots, and, but for
their blunter apices, would be indistinguishable from the first series of
hybrids having Tuberous Begonias as seed parents.
Norrt.—At the Conference illustrations were shown and brief notes
given of other hybrids than the above described, viz.—
(1):Hybrid Albucas, involving in a variety of ways the following
4
)
Fis. 91.—Rep Tusrrous Brconta x B. coccrnea (nat. size).
species : A. corymbosa, A. prolifera, A. caudata, A. Nelsoni, A. fasti-
giata, A. trichophylla, and A. minor. It was mentioned that as many as
five of these were united in the parentage of certain of the crosses.
(2) Begonia semperflorens x B. fuchsioides.
(3) Abutilon Darwinii, var. (2) x.A. megapotamicum variegatum.
(4) Centaurea ragusina candidissima x C. Scabiosa.
It is intended to incorporate the notes and figures of Albucas in a
N2
180 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
work at present in course of preparation. ‘The description of the other
hybrids named may well be postponed. ,
It remains to be mentioned that the whole of the experiments detailed
in the present paper have been carried out at Greenside Nursery, St.
Andrews, under most favourable circumstances.
Discussion.
Mr. Wesser: I should like to say, in regard to the parentage of the
two Begonias which the doctor used in order to secure the spotted
hybrids, that this seems to me to be exceedingly interesting, as it is a
new feature. I should like to know if it is at all probable that the
parents were mixed in any way, and that this may be a reversion to some
previous parent.
Dr. Witson: The Tuberous Begonias, as everybody knows, are com-
plex hybrids, so you might look for reversion. I am sorry I do not
know enough about the parent species to say if any of them have spotted
leaves; but it should be borne in mind that the leaves of B. coccinea are
certainly spotted sometimes. If anybody has grown it from seed he may
know whether it is spotted in its early stages.
==
ZE
j
22
\ \\\
\\) \\
\\\
Fic. 92.—Puatanoprsis Luppr-vrionacea. (Jowrnal of Horticulture.)
(P. LuppeMAnniana x P, vioLacea.)
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 181
HYBRIDISATION VIEWED FROM THE STANDPOINT OF
SYSTEMATIC BOTANY.
By R. Auten Rotrs, A.L.S., Kew.
“Ty the year 1819,” remarks Herbert, “having for some years previous
paid attention to the production of hybrid vegetables, .. . I was induced
. . . to address some detailed observations on the subject to the Horti-
cultural Society, which were published in the ‘ Transactions’ of that
body (iv. pp. 15-50). . . . Soon after the publication of that communication
. . . L was accosted by more than one botanist in the words, ‘I do not
thank you for your mules,’ and other expressions of like import, under
an impression that the intermixture of species, which had been com-
menced and was earnestly recommended to cultivators, would confuse
the labours of botanists, and force them to work their way through a
wilderness of uncertainty ; whereas it was evident to myself that it would,
on the contrary, afford a test whereby the accuracy of their distinctions
might be more satisfactorily investigated, many of the errors of their
systems eradicated, and its details established upon a more solid founda-
tion, and less upon the judgment and caprice of individuals’’ (‘* Ama-
ryllid.,’’ pp. 835, 336). A period of upwards of sixty years has since elapsed,
during which period the practice of hybridisation has progressed by leaps
and bounds, and with the greatest benefit to horticulture, though the
gain to systematic botany is not yet so apparent. The fact, certainly,
that hybrids occur in a wild state is now more or less admitted, and
many such plants have been recognised and described ; indeed, Herbert
himself quotes a list of no fewer than nineteen genera in which spon-
taneous hybrids had already been recorded—which fact doubtless
influenced his remarks—-but even at the present day there is a good deal
of scepticism among systematic botanists on the subject, as may be seen
from a recent controversy respecting the genus Hpilobiwm (the Willow-
herbs).
As long ago as 1831 Lasch recorded the occurrence of supposed
natural hybrids in this genus, and enumerated several which he believed
he had recognised (“ Linnza,” vi. pp. 493-497) ; while others were subse-
quently added, until in 1884, when Haussknecht monographed the genus,
he enumerated a list of over sixty European ones. After perusing this
work the Rey. E. 8. Marshall collected a number of remarkable British
forms, and sent them, with others gathered by friends, to Prof. Hauss-
knecht for determination. This was repeated for three successive years,
with the result that twenty-seven natural hybrids were recognised, two of
them being new to science (“ Journ. of Bot.,” 1889, pp. 148-147 ; 1890,
pp. 2-10; 1891, pp. 6-9).
The correctness of Haussknecht’s views was soon challenged. The
well-known botanist Mr. C. B. Clarke, F.R.S., wrote: ‘‘ Haussknecht’s
. . . hybrids are altogether beyond me” (l.c., 1891, p. 228); to which
Mr. Marshall replied that the question of hybridity was not to be “ dis-
182 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
missed offhand, as though it could be safely ignored. . . . I can affirm
that anyone with a fairly quick eye will soon be able to settle the ques-
tion for himself, as regards this particular genus, beyond all reasonable
doubt. . . . I cannot see why it should be inconceivable for insects to do
unconsciously what all are agreed that florists do consciously and more
clumsily ’’ (/.c., 1891, p. 298). Mr. Clarke retorted: “I have not...
dismissed hybrids offhand; where I have had time to come to close
quarters with them, however, they have invariably broken down.” He
then described how they ‘ arise’’ (which is too long to repeat), con-
cluding: “ The makers of hybrids often go no further than the diagnostic
characters of systematists ; their hybrids are not hybrids between any two
plants that ever lived, either species, crosses, or individuals, but hybrids
between two of the hybrid-monger’s own diagnoses ”’ (1.c., 1892, p. 80).
This Mr. Marshall not unnaturally described as “ caricature pure and
simple ’’ (/.c., 1892, p. 107).
Mr. N. E. Brown, in the Supplement to Syme’s “ English Botany,”’
published in 1892, also remarked of these twenty-seven supposed natural
hybrids: ‘“‘Supposed to be natural hybrids, and are considered as being
intermediate in character between their supposed parents. Possibly
some of them may be hybrids, but those ... that I have seen, named
by Prof. Haussknecht, Rey. E. 8. Marshall, and others, appear to me at
the utmost but trifling variations of one or other of their supposed
parents, the differences between the supposed hybrid and the species it
most resembles being no greater and sometimes not as great as may
often be found between individuals in a bed of seedlings from one plant,
and I see no use in inserting in our floras descriptions of such plants”’
(ls6.5:DsL00).
One of these very plants had long previously been raised artificially,
though none of the authors mentioned seems to have been aware of the
fact. Sir James EK. Smith, in 1800, had remarked concerning H'pilobiwm
roseum: ‘Is it possible it may have originated from seeds of the latter
[E. tetragonum] impregnated by the pollen of EH. montanum?”’
(“ Engl, Bot.,” x., t. 693.) In order to test this suggestion Dr. Bell-
Salter, about the year 1842, fertilised H. tetragonwm with pollen of
EH. montanum ; seeds were readily produced, and hybrids obtained, which
were described as intermediate between the parents, but different from
E. rosewm. He then reversed the cross, but the progeny proved indis-
tinguishable. ‘These hybrids were raised true from seed for four succes-
sive years, and up to the date of his writing (1852) plants continued to:
make their appearance (‘‘ Phytologist,” iv. p. 739).
The result of this experiment was doubly interesting, for not only is
EH. rosewm now recognised as a common and widely diffused species, but
the hybrid has also long been known in a wild state. According to
Haussknecht it was described as long ago as 1831 by Lasch under the
name of H. swbtetragono-montanum (‘ Linnea,” vi. p. 495), and by
Celakovsky, in 1881,as #. Freynii (“ Prodr. Fl. Bohem.,” p. 881). It is
found in several different localities where its parents grow intermixed.
These facts are given to show the diverse views which still prevail, and
it may seem strange to hybridists that such an amount of scepticism, and
even prejudice, should still exist. The reason, however, is not difficult to-
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 183
explain. Botanists necessarily have to base their system of classification
upon the similarities and differences which exist in the plants they investi-
gate, and can hardly be expected to view the obliteration of their most
reliable marks of distinction, which the work of the hybridist entails, with
equanimity. And it is notorious that in certain groups the marks of
distinction between species, and even genera, have been broken down by
this means, with the result that hybrids, for the most part, have been
regarded unsympathetically by botanists or ignored. Some, it is true,
have contended that hybridisation is also carried on in nature, but their
views have met with a good deal of opposition, as we have just seen.
On the other hand, hybridists have done very little to remove this.
prejudice. They have, for the most part, devoted themselves to raising
new and improved races of garden plants, without much regard for the
botanical side of the question, which perhaps helps to explain the
undoubted want of sympathy between the two classes of workers, and
which I hope this Conference will at least do something towards.
removing.
It is a fact beyond dispute that certain plants which occur in a wild
state, and have been described as species, have also been produced arti-
ficially by crossing together two other distinct kinds ; and that such plants
are natural hybrids can scarcely be denied by the greatest sceptic. The
number, I am convinced, might be rapidly increased if hybridists would
make the necessary experiments. It is perhaps too much to expect them
to demonstrate the origin of our much-disputed Willow-herbs, but there
are groups which they have already in hand in which certain crosses
might be made. Among Roses, for example, Crépin has described
numerous wild hybrids (‘‘ Bull. Soc. Roy. Belg.,” xxxiii. pp. 1-149), while
in gardens numerous artificial crosses have been made ; yet Mr. Baker tells
me that so far as he knows not one of these artificial crosses has demon-
strated the origin of any wild hybrid, the reason of course being that the
right species have not yet been crossed together. Botanists themselves
might do more to demonstrate the truth of some of their speculations on
the subject.
A good many experiments have already been made, and with most
promising results. Among the earliest undertaken with this express
object were those by Herbert in the genus Narcissus. About the
year 1835 a collection of the known Narcissi was made at Spofforth for
the completion of an arrangement of the Amaryllidacere ; and with a
desire of seeing the fruit of some of Haworth’s genera, application was
made for seed to various cultivators, when it was found that no one had
ever known a seed to be produced. The suspicion then arose that they
might be hybrids, and accordingly certain experiments were made. WN.
imcomparibilis was known to be wild in France, and it had been a ques-
tion among collectors whether it was generated accidentally between the
common Daffodil and N: poeticus, which Herbert remarked might be
expected to produce such a hybrid. He accordingly crossed a Daffodil
with pollen of N. poetiews, and when the seedlings flowered they proved
identical with N. incomparibilis, as may be seen by consulting the coloured
figure (‘“‘ Bot. Reg.,” xxix., t. 38, fig. 5). In a similar way Herbert
thought that ifthe Daffodil would cross with the Jonquil, N. odorus might
184 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
be produced, and this experiment was also successfully made, and the
opinion verified. “ Plants,’ he remarked, “ have, been raised both by
myself and by Mr. Trevor Alcock, near Caermarthen, and, having flowered,
have shown that the Linnean N. odorus, the genus Philogyne in all its
variations, is cross-bred between Ajax and Jonquil ” (‘‘ Journ. Hort. Soc.,”’
ii. p. 24). The cross between the Daffodil and N. poeticus was repeated
more than once, and also reversed, and numerous varieties produced,
which Herbert considered “ sufficient to establish the point that the
several varieties, single and double,’ of N. incomparibilis were hybrids
between the two species (J.c., p. 22).
The experiment was confirmed by Leeds, who raised N. incomparibilis
expansus from N. pseudonarcissus, var.major, crossed with poeticus (Moore
and Ayres, “ Gard. Mag. Bot.,”’ ili. p. 289, fig. 2), and also N. Leedsii from
precisely the same parentage (J.c., p. 169, fig. 2). Commenting on this,
Mr. Leeds remarks: “It is quite clear... that ¢ncomparibilis is no
species. .. . I think . . . the number of species is very small.’ Yet
in 1888 we find Mr. Baker enumerating N. incomparibilis as a species,
and N. Leedsii as a hybrid (“‘ Handb. Amaryll.,” pp. 5,14). Grenier and
Godron also treat N. incomparibilis as a species, mainly because it has been
found growing by itself, but a scarcely distinguishable plant found growing
with its two parents they admit as a hybrid, under the name of N. pseudo-
narcisso-poeticus (‘ Fl. de France,” ili. pp. 254, 255). It is known, how-
ever, that both incomparibilis and odorus become naturalised in suitable
localities, and their existence in isolated spots in no way disproyves
their hybrid origin.
Herbert believed that other so-called species were really hybrids,
adding, ‘‘I have more than once had seed from N. poeticus by the
Jonquil, which would indubitably have produced N. gracilis, but the
seedlings have been neglected and the labels mislaid”’ (“‘ Journ. Hort. Soc.,”’
ii. p. 26). He also raised N. Spofforthie by crossing N. incomparibilis with
the pollen of N. poeticus, and expressed himself as being as confident of
the origin of some others asif he had “obtained them from seed,’ adding,
‘«« And I have not troubled myself to make the like ”’ (/.c., p. 22).
Messrs. Damman, of Naples, it may be observed, have now demon-
strated the hybrid origin and parentage of N. gracilis, Sabine, and proved
the correctness of Herbert’s opinion, for seedlings between the Jonquil
and N. Tazetta raised by them certainly belong to N. gracilis. They,
however, used the Jonquil as the seed parent. N. tenwior, Lois, which
Mr. Baker also classes as a distinct species, is a form of the same hybrid.
The Rey. G. H. Engleheart has proved the hybrid origin of N. biflorus,
Curt., by crossing N. poeticus with the pollen of N. Tazetta (“ Journ.
Roy. Hort. Soc.,” xii. p. 317, also lii.), and subsequently from the reverse
cross (l.c., xix. p. 12), some of the seedlings being identical with wild forms,
thus confirming what has long been suspected. Grenier and Godron, it
may be remarked, enumerate N. biflorus as a species (‘‘ Fl. de France,”
iii. p. 256), but on the next page they give N. Tazetto-poeticus, though they
were unable to point out any tangible character by which the two could
be distinguished.
The pretty little N. pulchellus, Salisb., has also been reconstructed
by the Rey. G. H. Engleheart by a cross effected between N. triandrus
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 185
and the Jonquil, the seedlings proving absolutely identical with the wild
plant. Mr. Baker classes this hybrid as a form of N. triandrus.
Perhaps the first direct experiment of this kind was made by Linnzus,
who suspected the hybrid origin of a certain Tragopogon in the garden
at Upsala, where 7’. pratensis and 7’. porrifolius were cultivated. Accord-
ingly he fertilised flowers of the former with pollen of the latter, and
obtained seedlings, which flowered in the summer of 1759, and proved
identical, receiving the name 7’. hybridum (“ Amoen. Acad.,” x. p. 126).
This hybrid has since been found in a wild state with its two parents.
A hybrid Verbascum was also produced in the garden at Upsala in
1761, from seeds of V. lychnitis impregnated with the pollen of V.
Thapsus ; which Withering states also grows wild in Kent (‘“ Brit. Pl.,”
ed. 3,11. p. 249). Mr. Griffith, of Denbighshire, also raised it artificially
from the same cross, and sent specimens to Sir J. E. Smith
(“Sm. Engl. Fl.,” i. p. 310). Kélreuter also raised it, both from the
same and from the reversed cross. As a wild plant it is widely
diffused in Central Kurope.
Another hybrid Verbascwm was also recorded by Withering (l.c., p. 248),
whose history is thus given. In the spring of 1789 a Mr. Robson planted
a root of V. nigrum near one of V. Thapsus in his garden, when both
flowered well, and the latter was allowed to stand and shed its seeds.
Next spring several plants appeared which were different from either
species, but partook of the characters of both, and for five successive
seasons they flowered, but produced no perfect seed. Though rightly.
called a hybrid, it was recorded under its Linnean name of V. Thapsus
var. Thapso-mgrum, which name itself suggests that its real origin was
pretty shrewdly guessed. Kdélreuter also raised it from the same and
from the reversed cross. It is found wild in various localities in Europe,
and has various names.
Various other wild species have been crossed together artificially, and
the resulting hybrids have proved identical with wild plants, which in
many cases have been originally described as species, and sometimes
under various names. According to Focke, no fewer than twenty-three
distinct combinations have been made artificially which have yielded
hybrids identical with wild ones, and one of these, namely, V. blattaria x
pheniceum, has also appeared spontaneously in gardens where the two
species have been grown. One other has been so far proved that spon-
taneous hybrids, agreeing with wild ones, have appeared where V.
phlomoides and V. speciosum have grown side by side, the pollen having
evidently been transferred by insects, as occurs in nature. In at least
six of the above cases the parentage was also reversed with the same
result.
Digitalis supplies some wild hybrids whose origin has been artificially
demonstrated. For example D. purpurascens, Roth, has been reconstructed
by crossing and recrossing D. lutea and D. purpurea; and D. media,
Roth, in the same way from D. purpurea and D. ambigua (grandiflora).
The former hybrid is evidently raised with the greatest facility, for it
has appeared in several gardens where the two parent species are grown.
D. ambigua has also been crossed with D. purpurea and with D. lanata,
in each case yielding hybrids which also occur wild.
186 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
The hybrid origin of Gewm intermedium has long been known. Dr.
Bell-Salter has recorded how, acting on a suggestion which had been
thrown out that it was a hybrid, he crossed G. rivale with pollen of G.
urbanum, and the resulting seedlings proved exactly identical with the
wild plant. It also proved fertile, and reproduced itself true from seed
(“ Phytologist,” iv. p. 739). Giirtner also raised it both from the same and
the reverse cross, and it is known to occur spontaneously in gardens where
the two species are cultivated together. Gewm coccinewm 9 and G.
rivale g were also crossed by Girtner, and yielded a hybrid which has
been found in the Rhodope mountains by Janka.
The willows are now known to hybridise with the greatest facility in
a wild state, though the early salicologists were mostly unwilling to
recognise the fact. By degrees, however, the probability of the pheno-
menon was admitted, and Wichura demonstrated the truth of these
suppositions by raising artificially forms identical with those which had
long been known in a wild state. The Rev. E. F. Linton has also raised
several hybrids in his garden at Bournemouth, and has kindly supplied
me with a few facts for the present paper. Wichura appears to have
raised artificially eight hybrids which also occur wild, to which Linton
has added at least six others, a few of which may now be considered.
Salix rubra was for many years ranked as a widely diffused species, yet
Wichura obtained it artificially by crossing S. purpurea with the pollen of
S. viminalis. Linton also raised it as a seedling from a viminalis catkin,
which had evidently been pollinated with S. purpurea, probably by bees.
The others raised by Linton are as follows :—S. repens? x purpuread
yielded S. Doniana, Sm., originally described as a species by Smith.
S. viminalis ? x repens 8 produced several seedlings agreeing well with
S. rosmarinifolia, L., as figured in Sowerby and Smith’s “ English
Botany,” t. 1865 (t. 1363 of ed. 3), which Wimmer considered as
representing this cross. S. viminalis x triandra produced S. hippophar-
folia, Thuil., which was originally described as a species, but afterwards
considered to be a hybrid with this parentage by Wimmer. Wichura
records three unsuccessful attempts to raise this hybrid, in 1856, 1857, and
1858, S. triandra being used as the seed parent (‘‘ Bastardbefr. Pflan-
zenr.,” p.13). S. repens 2? x Lapponum g produced a hybrid agreeing well
with wild specimens from Sweden. S. phylicifolia? x herbacea g yielded
a hybrid strongly resembling S. Moorei, which is believed to have
originated from this cross (‘‘Journ. of Bot.,” 1896, p. 470). Finally
S. Lapponum@ x phylicifolia 8 yielded a very variable hybrid, which has
since helped to determine the origin of a wild Scotch plant. A few
crosses entirely failed—indeed the process is said to be liable to all sorts
of miscarriages—and a few others yielded hybrids not yet recognised in
Britain, but the results are certainly valuable and suggestive.
Some of these proved hybrids, as we have already seen, were originally
described as species, as were also many others whose hybrid origin is now
fully recognised. In 1830 Sir J. EH. Smith recognised sixty-four British
species of Salix (** Engl. FI.,” ed. 2, iv. pp. 163-233. ‘* Full thirty years,”
he observes, ‘‘ have I laboured at this task [of specific distinction], ten of
them under the instructive auspices of my late friend Mr. Crowe, in whose
garden every Willow that could be got was cultivated. . . . The plants
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 187
were almost daily visited and watched by their possessor, whom no
character or variation escaped: seedlings innumerable, springing up all
over the ground, were never destroyed till their species were determined,
and the immutability of each verified by our joint inspection. This was
the more material, to set aside the gratuitous suppositions of the mixture
of species, or the production of new or hybrid ones, of which, no
more than of any change in established species, I have never met with
an instance’”’ (/.c., p. 164). In 1890 Dr. Buchanan White wrote a Mono-
graph of the British Willows (“ Journ. Linn. Soc.,” xxvii. pp. 333-457),
in which he enumerated seventeen species and forty-one hybrids. Many
of Smith’s so-called ‘‘ species’’ are now ranked as varieties, but at least
six of them are hybrids, and the number may yet have to be increased,
for secondary hybrids have been raised artificially, and on the Continent
a few have been recognised in a wild state; and the result of such recross-
ing of a species with its hybrid offspring might easily be passed over as a
variety only unless its origin was known.
An even worse state of confusion exists in the genus Hieraciwm, which
seems to be about where Salix was in Smith’s time. ‘‘ New species,” so
called, have recently been described wholesale, both on the Continent and
in England, and in some cases the constancy of their characters has been
tested under cultivation. But what is their systematic value? Babington
recognises thirty-two British species, but Bentham thinks that seven
*‘ will probably be found to be the only truly botanical species indigenous
to Britain.’ What, then, are the others? Bentham says the species are
some of them very variable, and specimens are frequently found appa-
rently intermediate between some of the commonest ones.’’ The phrase
is suggestive of their origin, and I have little doubt that some of the
recently described British ‘‘ new species’’ are natural hybrids. Indeed,
two of three were indicated as hybrids by Hanbury, though a further
remark perhaps indicates why others were not so regarded :—“‘ As recent
numbers of this Journal show that there are those who refuse to believe
in the existence of hybrids, even among. . . [Salix and Epilobium] I
give up as hopeless the task of endeavouring to convince such that they
exist among Hieracia ”’ (‘‘ Journ. of Bot.,’’ 1892, p. 870). They do exist,
nevertheless, doubtless in large numbers, and at all events some have
been reconstructed artificially, being certainly identical with the wild
types. F. Schultes and G. Mendel raised several artificially, and at least
seven of them I have seen in the dried state. Many natural hybrids
have been recognised by Continental authors, and I quickly found thirty
such plants in the Herbarium at Kew, with their supposed parentage
indicated, and in two cases both the wild and artificially raised hybrids
are represented. Four artificial crosses between distinct species, which
also occur wild, are recorded by Focke, namely H. awricula x pilo-
sella, H. prealtum x pilosella, H. auricula x pratense, and H. awran-
tiacum x auricula, and it appears that the second of these crosses proves
the origin of no fewer than eleven so-called “ species ’’—plants which at least
have received specific names—and the last as many as four. Surely no
more eloquent comment is needed, and we may pass on.
Fubus is another genus which presents that “ chaos of undecided forms
in the face of which all the efforts of botanical describers miscarry,” and
188 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
I believe that no further progress is possible without a fuller recognition
of the fact that hybridisation, as well as polymorphism, occurs. Natural
hybrids certainly occur, and Focke has succeeded in reconstructing two
of them artificially, namely, R. pruinosus, Arrh., from R. Ideus 2 x
cesius ¢; and R. neglectus, Peck, from R. Ideus subsp. strigosus 9 x —
occidentalis $.
Incredible as it may seem to-day, few botanical questions have been
more often or more warmly discussed than the one whether the Cowslip
and Primrose are distinct species or only forms of one, the reason being
the occurrence of intermediate forms, called Oxlips, which we now know
to be hybrids. Linneus, who certainly had a suspicion of the truth,
ranked both the Primrose and Oxlip as varieties of P. veris (the Cowslip).
Sir J. E. Smith, in 1790, clearly suspected the Oxlip to be a hybrid,
remarking, ‘‘If not a hybrid production between the other two, it may
perhaps with the greatest propriety be reckoned a variety of the Primrose ”’
(Sowerby and Smith, “ Engl. Bot.,’ t. 4). Various experiments were
made to ascertain the truth of this hypothesis. Mr. Hewett C. Watson
brought into his garden a wild ‘Claygate Oxlip,” planting it near Cows-
lips and Primroses, so that the flowers might be hybridised by bees—
if hybridisation really took place. He carefully marked it, and sowed the
seeds, and from them he states that he obtained plants of the Oxlip,
Cowslip, and Primrose.* By a similar process from Cowslip seed he
could get only Cowslips and Oxlips, from which he concludes that the
“hybridisation hypothesis wears an aspect of plausibility’’ (‘ Phytol.,”’
iii. pp. 146-149). Godron, however, made the much more promising experi-
ment of crossing and recrossing the two species, from which he raised
numerous intermediate forms, which set the matter at rest. This ques-
tion has been somewhat complicated by the fact that there is a true
species, Primula elatior, Jacq., which somewhat resembles the hybrid
Oxlip, and the two were formerly confused together. The species is now
known as the Bardwell Oxlip. Mr. Miller Christy has published an
exhanstive paper on the subject (‘‘ Journ. Linn. Soc.,” xxxiii. pp. 172-201).
Some years ago in a batch of Sarracenias, imported by Mr. B. 5$.
Willams, of Upper Holloway, a plant was found which combined the
characters of S. purpurea and S. flava, and was named S. Williamsiv.
Mr. Stevens, of Trentham, crossed S. purpurea with S. flava, and his
seedling was named S. Stevensii. The late Mr. T. Moore is said to have
observed respecting them :—‘‘ These two plants have the same parents.
. . » We have little doubt the crosses were made the reverse way”
(Burbidge, “ Cult. P1.,’’ p. 527). Recently a second natural hybrid has been
recorded, Mr. G. W. Oliver remarks :—‘ An instance occurred under my
own observation a few years ago in a well-marked Sarracenia hybrid
which was found growing near Wilmington, N.C. Only three species
were growing near the hybrid: these were S. rubra, S. purpurea, and S.
flava ; in the hybrid the form of the leaves suggested S. purpurea as the
seed-bearer, with S. rwbra as the pollen parent. This surmise proved
* These specimens are preserved in his herbarium, now at Kew, and, having
examined them, I can say that they are not true Primroses and Cowslips, which would
imply complete reversion to the parent forms. Whether they are secondary hybrids
with either parent, or partial reversions, is, of course, problematical.
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 189
correct, as under cultivation pollen from S. rubra artificially applied to
the stigma of S. purpurea produced exactly the same hybrid as was found
growing wild” (“ Amer. Gard.,” June 8, 1899, p. 400). It is further
interesting to add that from the reversed cross Messrs. Veitch had already
raised S. Chelsoni (‘ Gard. Chron.,’’ 1880, xiil. pp. 722, 725, fig. 125).
Among Orchids a good many supposed natural hybrids have been
proved artificially, the first being Phalenopsis intermedia, which will
always retain a historical interest, as the first recognised hybrid among
tropical Orchids, and the first whose origin was experimentally demon-
strated, an interval of thirty-three years elapsing between the two events.
It appeared as a single plant in an importation of P. Aphrodite (then
known under the erroneous name of P. amabilis), received by Messrs.
James Veitch and Sons, in 1852, from the Philippines, through their
collector, Thomas Lobb, and was described and figured in the following
year (“ Paxt. Fl.Gard.,” iii.p. 163, fig. 316) by Dr. Lindley, who remarked :
- Fie. 93.— PHAuENopsts x InTERMEDIA (Veitch’s ‘“ Manual of Orehidaceous Plants.”’)
‘It is not improbable that this beautiful plant is a natural mule between
P. amabilis and rosea,’ and then proceeded to show its resemblance to
both species. Years afterwards, when the raising of artificial hybrids
had become an established business, Messrs. Veitch proceeded to test the
truth of this hypothesis by crossing P. Aphrodite with the pollen of P.
rosea, and the resulting seedling proved absolutely identical with the
wild plant (Rolfe in ‘“‘ Gard. Chron.,’’ 1886, xxvi. pp. 169,212). The shrewd-
ness of Lindley’s observation will be inferred when it is remembered that
Calanthe x Dominii, the first artificial hybrid among Orchids, did not
flower until 1856.
In 1886, also, Lelia x lilacina, Rehb. f., from the collection of
F, A. Philbrick, Esq., was described as a natural hybrid between Lelia
erispa and L. Perrinii, the two species from which Lelia Pilcheri had
previously been raised by Mr. Dominy, and although the former presented
some slight differences from L. Pilcheri, Reichenbach remarked, ‘ I
believe it must be regarded as a variety of that mighty beauty.”
In 1888 the origin of another natural hybrid Orchid was proved.
190 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
When Masdevallia splendida and M. Parlatorea were described, some
ten years previously, Reichenbach had thrown owt the suggestion that
they might be natural hybrids, and Messrs. Veitch accordingly crossed
together the two species with which they came home, namely WM. Vevtch-
iana and M. Barleana, using the latter as pollen parent. In 1888 the
seedlings began to flower, and proved identical with the wild hybrids,
which were now seen to be simply forms of one.
The first artificially raised Odontoglossum flowered in 1890, and
proved interesting on another account. It was raised by M. Leroy,
gardener to Baron Edmond de Rothschild, of Armainvilliers, near Paris,
by crossing O. crispwm with the pollen of O. luteo-purpureum, and was
named O. Leroyanum. It was, however, immediately recognised as 2
form of O. x Wilckeanwm, which in 1894 had been described by Reichen-
i! " | i ?
(
Wi
Fic. 94.—Opontoaiossum x Drnisonre. (Gardeners? Chronicle.)
bach as a natural hybrid between the self-same two species, and soon
afterwards it was traced back to 1872, when it flowered in the collection
of Lord Londesborough, and was described and figured under the name
of O. x Denisome.
A year later Messrs. Veitch flowered a third hybrid which had been
raised with the express purpose of proving the origin of suspected wild
hybrids. This was Odontoglossum x excellens, described by Reichenbach
in 1881 as probably a natural hybrid between O. Pescatoret and O. tri-
pudians. The second parent suggested was obviously incorrect, as the
characters of the hybrid agree much better with O. triwnphans, and
consequently the pollen of this was used in a cross with O. Pescatoret,
which yielded offspring absolutely identical with the wild plant.
In 1892 Messrs. F. Sander & Co. also flowered a hybrid which proved
the origin of a wild plant. It had been obtained by crossing Cattleya
intermedia and C. Forbesii, and on flowering I immediately recognised
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 191
it as identical with C. Krameriana, described by Reichenbach, in 1888,
as a natural hybrid with this parentage. A seedling from the same
batch which flowered in May 1891 was exhibited under the name of
C. Lowryana. Afterwards it appeared that C. fimbriata, which was
raised by M. Bleu, of Paris, and flowered in 1878, was identical. And
there is a Cattleya Isabella described by Reichenbach, in 1859, as an
ally of C. Forbesii and C. intermedia, having characters of both, which
is probably identical. It flowered with Messrs. Booth & Sons, of
Flottbeck, near Hamburg.
In 1893 Anguloa x media was added to the list. It was originally
raised in the collection of the late J. C. Bowring, Esq., of Windsor, from
A. Clowesw and A. Ruckeri, flowering in 1881, and seven years later an
identical hybrid flowered with Messrs. Veitch. It afterwards flowered in
the collection of R. H. Measures, Esq., of Streatham, among imported
plants (‘‘ Orch. Rey.,” 1893, p. 40), and as the parents are known to
grow together one need not feel particularly surprised.
The following year hybrids of two other genera were added to the
list, and in much the same way. ‘The first was Calanthe x Veitchii,
Fic. 95.—Canantue x Verrceuu. (Veitch’s ‘‘ Manual of Orchidaceous Plants.’’)
originally raised from C. rosea 9 and C. vestitag by Mr. Dominy,
flowering for the first time in 1859, and afterwards detected in Burma,
where the two parent species grow together, by Mr. Boxall. The
latter flowered with Messrs. Hugh Low & Co. (“Orch. Rev.,’ ii.
p- 19). Then came Dendrobium x Rolfee, raised by Messrs. I. Sander
& Co., from D. primulinum? and D. nobiles, flowering in 1892, and
afterwards detected among imported plants of D. nobile in the collection
of Major-Gen. Berkeley, of Southampton (‘‘ Orch. Rey.,” ii. p. 114), and
afterwards elsewhere. It has since been discovered that D. Pitcherianwm
was described by Reichenbach in 1888 as probably a natural hybrid
between the same two species.
It is not necessary to continue the record further in chronological
order, but it is curious to note that the nine hybrids already mentioned
192 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
belong to eight different genera. Cattleya at present holds the record in
point of number of natural hybrids whose parentage has been proved.
The second on the list is the magnificent C. x Hardyana, which originally
appeared in 1884 in the collection of G. Hardy, Esq., and was afterwards
artificially raised from C. Dowiana aurea ? and C. Warscewiczvi g, by N. C.
Cookson, Esq. (‘‘ Orch. Rev.,”’ 1896, p.298). Then came C. x hybrida, Messrs.
Veitch’s earliest hybrid Cattleya, raised from C. Loddigesi and C. guttata,
and which afterwards appeared among imported plants with Mr. W.
Brooks, of Weston-super-Mare (‘‘ Orch. Rey.,”’ 1897, p. 833). C. x Claesiana
Fic. 96.—Carrinya x Harpyana. (Orchid Review.)
was introduced by Messrs. Linden, of Brussels, some six or more years
ago, and has now been raised by Mr. T. L. Mead, of Florida, from C.
intermedia 9 and C. Loddigesii (‘ Orch. Rev.,’’ 1899, p. 72). And only
yesterday I recognised among the exhibits of M. Charles Maron a plant
identical with the natural hybrid C. x Patrocinii (see ‘‘ Orch. Reyv.,”’ 1893,
p. 843), under the name of C. x Gaudi. It had been raised by the
exhibitor from CU. Leopoldi ? and C. Loddigesiig%. [Since this paper was
written I have found the record of C. x Russelliana, raised by M. G.
Mantin, of Paris, from C. Warneri and C. Schilleriana, which should
prove identical with C. x Whitei (see ‘‘Orch. Rev.,’’ 1899, p. 292).—R. A. R. }
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 193
Of the five or six distinct wild Lelio-cattleyas known, only one has
been raised artificially—namely, L.-c. x Schilleriana, obtained by Messrs.
Charlesworth & Co., from Lelia purpurata 2 and Cattleya intermedia 3
(* Orch. Rey.,’’ 1898, p. 167). Asa wild plant it has been known ever
since 1855, in which year it was described as a species, under the name
of Lelia Schilleriana. There are, however, seedlings in existence which
ought to prove the parentage of two if not three others.
One other Odontoglossum claims a place in our list—namely, O. x
elegans, described by Reichenbach, in 1879, as a natural hybrid between
O. cristatum and cirrhosum (‘* Gard. Chron.,’’ 1879, xi. p. 462). Messrs.
Linden, however, have raised an identical hybrid by crossing O. cirrhosum
with the pollen of O. Hallii. It flowered early in 1897, and was described
Fie. 97.—OponrocLossum x ELEGANS. (Mr. Pollett’s Catalogue.)
and figured under the name of O. cirrho-Halli (“ Lindenia,” xi. p. 85,
t. 569).
Phalenopsis x Veitchiana-appeared as a solitary specimen among
Philippine importations of Messrs. James Veitch & Sons, and flowered in
1872, when it was described as a natural hybrid between P. Schilleriana
and P. rosea (Rehb. f. in “ Gard. Chron.,”’ 1872, p. 935), a view since con-
firmed by Messrs. Heath & Sons, who have obtained it asa seedling from
the former crossed with pollen of the latter (Hansen, “ Orch. Hyb.,”’
p. 331).
Lastly, and scareely less interesting than any of the preceding cases,
we have the remarkable fact that Dendrobium x Ainsworthii has
)
Fic. 98. - OponrocLossuM crrRHosuM. (Veitch’s ‘“‘ Manual of Orchidaceous Plants.”’)
Fic. 99.—Oponvocrossum Hani. (Veitch’s “‘ Manua’ of Orchidaceous Plants.’’)
Figs. 98 and 99 represent the two parents of Odontoglossum x elegans, figured on the preceding page.
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 195
appeared as a wild hybrid among importations of D. nobile. HKxamples
of D. awrewm also occur in the same importations (‘‘ Orch. Rev.,” 1899,
p. 99). Had the event occurred prior to 1874, when the seedlings which
were obtained by Dr. Ainsworth by crossing these two species together
. flowered for the first time, the plant would almost certainly have been
described as a species.
Fie. 100.—DeEnpropium x AInswortHu. (Gardeners’ Chronicle.)
At Chiswick yesterday plants were exhibited of a very curious
hybrid Fern raised by Mr. E. J. Lowe between Scolopendriwm vulgare
and Ceterach officinarwm, and which unmistakably combines the
characteristics of these two species, which are remarkably distinct both in
appearance and in the stations they affect. It is interesting to note
that a wild hybrid between them has also been found, in Istria, and
described under the name of Scolopendriwm hybridum (“ Kern. Nat.
Hist. Pl.,” ii. p. 582). I have not seen the latter, so cannot say how far
the two are identical.
A question much discussed many years ago was the supposed develop-
ment of cultivated Wheat from the wild Agilops by cultivation. The
facts, however, are briefly these. gilops triticoides occurs spontaneously
in Southern Europe along the edges of Wheat fields, and for various
reasons was supposed to be a hybrid between the Wheat and gilops
ovata, a small grass which occurs there. Over half-a-century ago Faber
grew this plant from a seed of 4. ovata, and it was afterwards produced
artificially by many experimenters, thus proving its hybrid origin. This
hybrid proved mostly sterile, but at length, in 1838, Faber obtained a seed-
ling which proved to be more like Wheat and more fertile, and by continuing
02
196 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Fic. 101.—Drnpropium avurEuM. (Veitch’s “ Manual of Orchidaceous Plants.’’)
Fig. 102.—Denpropivm nopite, (Veitch’s ‘“ Manual of Orchidaceous Plants.’’)
Figs. 101 and 102 represent the two parents of Dendrobium x Ainsworthii,ffigured
on the preceding page.
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 197
the process he obtained a fertile race, which he called ‘‘ Aigilops Wheat ”’
(44. spelteformis, Jord.), and which, according to Focke, remained con-
stant in character and fertile after being cultivated for a period of forty
years.
I have discovered several curious records respecting hybrid Ericas.
Mr. Andrew Turnbull, the well-known raiser of these plants, remarked in
1880 :—“ Many Heaths introduced from the Cape as species are in my
opinion natural hybrids, as several varieties can be raised from the same
pod of seed without impregnation.’’ This is not very conclusive, but a
little earlier we read :—‘‘ With regard to the hybridisation of Heaths I
commenced that shortly after I came to Bothwell Castle. I was not
then aware that Messrs. Rollisson, of Tooting, had practised it for twenty
years before me, . . . and a short time after I saw a list of Heaths,
said to be hybrids raised by them, and was surprised to see amongst them
some we had always considered as distinct species from the Cape, and as
such the date of their introduction, given in Loudon’s Catalogue, ranging
from eighty to one hundred years from the present date” (‘‘ Gard.
Chron.,’”’ 1880, xix. p. 179). A note by Mr. George Rollisson in 18438
is interesting in this connection :—‘‘ My much-lamented father practised
[hybridisation] upwards of fifty years ago: he confined himself principally
to Ericas. . . . From the period he commenced, viz. 1790, until
1841 he succeeded in obtaining nearly ninety varieties,’ a list of which
is given (‘ Gard. Chron.,” 1848, p. 461). I spent some time in the
attempt to identify some of these hybrids with wild examples, but without
success, and anyone who likes to take the subject up will soon discover
that there is the greatest confusion in the records. A remark on the
subject by the editor of the ‘‘ Gardeners’ Chronicle”? in 1880 is more
eloquent than anything which I can offer :—‘ In the times of which
Turnbull was speaking it was considered by a section of no doubt worthy
people to be almost an impious thing to raise hybrid plants. It was
deemed a sacrilegious interference with the laws of the Creator, and so
strong was this prejudice in certain quarters that some of the nurserymen
at that day were fain to conceal the hybrid parentage of the plants they
offered, and to catalogue them as if they were imported species from the
Cape” (1880, xiii. p. 177). No doubt natural hybrids occur, but their
identification must be left for the present.
I may conclude these examples by a few remarks respecting two
plants which are equally well known, both to botanists and horticul-
turists, namely, the Red and White Campions, Lychnis diwrna and
vespertina. Distinct as they are, both in appearance and in the stations
they affect, there has always been a great difficulty in distinguishing them
by any absolute characters. Linneus in 1753 made them varieties of
a single species, which he calledjL. dioica, enumerating a third variety
somewhat intermediate between the other two (‘Sp. Pl.” ed. 1, p. 437).
Smith in his various writings adopted a similar course, and in 1824 he
remarked: “ No solid, permanent sign of specific distinction has occurred
to me between a and £, though I have much wished to find one”
(Engl. Fl,” ii. p. 329). Both forms he showed to be common, but
there was a variety with “ flesh-coloured flowers ”’ found “in hedges and
fields, but rarely,” which spoiled the distinction. Various other authors
198 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
had been troubled with this question, and in 1794 Sibthorp had classed
the two as distinct; a view which had found supporters, when in 1818 the
following remark appeared in print :—‘ Mr. Woodward recently observes
that if the white and red be distinct the hermaphrodite variety with
flesh-coloured flowers is probably a hybrid between them ”’ (‘‘ Withering
Brit. Pl.,’”’ ed. 6, ii. p. 570). This suggestion afterwards proved correct,
for Giirtner in the summer of 1830 flowered a hybrid which he had
raised artificially between the two species, to which he gaye the name of
Lychiis dioica albo-rubra (“ Flora,’ 1831, p. 572). A year later he
raised the reverse cross, which he called L. d. rubro-alba (l.c., 1882,
p. 446). The natural hybrid is widely diffused both in England and on
the Continent, and was described in 1866 as Melandryum intermedium
(“ Schur. Enum. Pl. Transsilv.,’”’ p. 106), and a year later as M. dubiwm
(Hampe, ex Garcke, “ Fl. Deutschl.,” ed. 8, p. 66), besides having also been
considered as a variety of each of its parents. Even now the question
seems imperfectly understood, and long after the wild and artificially
raised hybrids had been identified together, we find Bentham writing of
L. diurna :—* Very near L. vespertina and perhaps a mere variety.”’ In
1863 Mr. Baker wrote :—‘ A plant is not unfrequent which looks like a
hybrid ”’ (‘‘ North Yorks.,” p. 209). He also sent examples to Boswell-
Syme, who was partially convinced, though one he thought was “only a
pale variety of L. diwrna, though, in the absence of the mature capsule,
it is difficult to give a decided opinion ” (‘‘ Engl. Bot.,” ii. pp. 69, 70).
Examples were also sent to Hewett C. Watson, and the latter both
collected it wild in Surrey and perpetuated it from seed * in his own
garden, as may be seen by a series of specimens preserved in his
herbarium, though I cannot find that he ever published his views
respecting them. The simple fact is that the two plants are thoroughly
distinct in numerous particulars, and affect such different habitats that in
some localities one or the other of them is completely wanting. But
where their stations are adjacent they hybridise together very readily,
and it is here that these intermediate forms occur which have puzzled
botanists so much. I may add that in 1863 Godron also raised the
hybrid from L. vespertina 2 x diurnaé.
The foregoing case is typical of many others. Natural hybrids have
been largely ignored or got rid of by the following processes. Some of
the more distinct have been described as species, the authors simply
judging them by their characters, without knowing anything of their
actual origin. Others have been treated as varieties of one of the parents,
on account of resemblances too patent to be ignored. And, in a few
cases, the presence of intermediates has led to the two parents being
regarded as simply forms of a single species. Each of these methods has
been applied in the case of the Lychnis just mentioned, but from the very
nature of the case the results are contradictory and unsatisfactory. The
only alternative is to assign to natural hybrids their true value, treating
them neither as species nor varieties, and this leads us to ask the ques-
tion, How may they be recognised? The answer is not easy, but a few
* A note on the sheet states that among the seedlings were forms with pink, white,
and red flowers. ;
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 199
considerations will help us to realise their essential distinctness as a
class.
A species may be described as a collection of like individuals inhabiting
a definite geographical area, more or less continuously or discontinuously
according to circumstances, and over which they have spread by diffusion
from some original birthplace. Widely diffused species are generally
variable, owing to modifications effected by change of environment, which
eventually result in the production of distinct but allied species, mostly
in distinct geographical stations, though by subsequent diffusion their
areas may again overlap. Many of these allied species retain their con-
genital affinity, yielding hybrid offsprmg when intercrossed, and when
such species grow in proximity to each other the pollen frequently gets
transferred by natural agencies, and under such conditions natural
hybrids frequently occur. Hybrids—natural or artificial alike—almost
invariably show a distinct combination of the characters of the two
parent species, which may usually be traced on careful examination,
though sometimes the influence of one parent preponderates to such an
extent that it becomes difficult to identify the second one. ‘They are
usually very variable, some individuals derived from the same two species
being so dissimilar as to have been at first considered essentially distinct
in their origin. Those which occur wild are usually found intermixed
with the parent species, though in the case of wind-borne seeds this may
not always apply. And they are frequently rare, as compared with the
parents, though some species hybridise with such facility as to form
notable exceptions.
These are, of course, only relative peculiarities, and afford no clue to
the identification of a hybrid as such. The fact is no absolute differential
character can be pointed out. It was formerly thought that hybrids
between distinct species were universally sterile, and consequently a so-
called “fertile hybrid ’’ was taken as evidence that the parents were only
forms of one; a view which long ago proved altogether untenable. We
now know that some bond fide hybrids are as completely fertile as their
parents, and even those that are sterile—i.c. have their reproductive
organs functionally impotent—frequently appear structurally perfect.
It is this absence of any reliable character by which a hybrid can be
recognised that constitutes the real obstacle to progress in our knowledge
of “natural hybrids.’ It is open to every sceptic to ask for “ proofs,”’
and we have already seen how the views of many shrewd observers have
been treated. It is not always sufficient to point out that such and such
a plant is rare, is only found where two other species grow together (not
where they grow separately), that it is intermediate in character, or that
it combines the characters of the two, and is evidently a natural hybrid
between them. The test of direct experiment is alone convincing in
many cases, and believing, as I do, that natural hybrids are more common
in certain groups than we have yet realised, I welcome any additional
light that can be thrown on the subject, from whatever source it may
come; and instead of viewing the work of the hybridist unsympathetically,
I only wish some of his energy could be diverted into other channels, for
I believe that nothing would do more to advance our knowledge than a
few well-directed experiments in those groups in which so much difference
200 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
of opinion exists. I need not enumerate them further, and I believe
that a deeper search among the scattered records'would add several to
the foregoing list of those whose origin has been demonstrated experi-
mentally.
There is one question remaining on which I should like to say a few
words, and that is whether the question of hybridisation may not have
to be considered even in connection with the very origin of species.
Kerner answers the question whether “ species”? are ever produced by
hybridisation in the affirmative, and adduces some very important evidence
in support of this view. In discussing it we need not go into the vexed
question of what is a species. We may take it that they exist, and for
the sake of clearness may adopt the Darwinian conception that they have
arisen by gradual divergence of character from a common ancestor. We
have already seen that certain hybrids are fertile, and can be reproduced
true from seed for years in succession. We may therefore term them
“hybrid races,” but we may ask, in what respect, apart from their origin,
which is known, can they be distinguished from certain “ species,’’ univer-
sally recognised as such, whose origin is not known? If difference there
be, we are not yet able to define it in words.
Kerner, in his ‘‘ Natural History of Plants,’’ has given some interesting
particulars about these hybrid races, from which we may make a few
extracts. A hybrid between Medicago falcata and sativa, known as
M. media, is widely cultivated as a fodder plant, and is propagated from
seed (vol. ii. p. 577). Salvia betonicefolia, a hybrid from S. nemorosa
and nutans, is aS common as its parents in grassland in Central Hun-
gary (p. 585). Betula alpestris, a hybrid between B. alba and nana, is
abundant in the Jura, Scandinavia, and in North Russia, here and there
whole copses of it being found (p. 586). Nigritella swaveolens, a hybrid
between N. angustifolia and Gymnadenia conopsea, is abundant in some
Swiss localities, hundreds of plants sometimes occurring in a single
meadow (p. 586). Hybrids between the Primrose and Cowslip occur in
thousands in upland meadows in the Eastern Alps (p. 586).
Rhododendron intermedium is a particularly interesting hybrid. In
some localities in the Tyrol there is a great variety of soil, and a very
rich flora, plants peculiar to schist formations and others found only on
limestone growing close together. Rhododendron ferruginewm and
R. hirsutum, though peculiar to these formations respectively, thus exist
here side by side, and intercross freely, the hybrid in some localities being
commoner than either parent. It seeds freely, and comes true from seed,
and thus fulfils all the requirements demanded of a species, being as
much a specific entity as either parent. The explanation is that the
flowers are a little lighter than those of R. ferrugimewm, but richer than
R. hirsutum; in fact, a brilliant carmine, which enables every plant to
be identified at a distance. It is thus more attractive to bees, and gets
fertilised with its own pollen. In some localities, where detritus from
the limestone occurs mixed with humus, the hybrids do better than R.
ferrugineum, and as wellas R. hirsutwm, so that it has an advantage
over the former in the matter of soil, and over both parents so far as
insect visits are concerned. It has thus a better chance of surviving
(p. 588).
HYBRIDISATION VIEWED FROM SYSTEMATIC BOTANY. 201
Salvia sylvestris, a hybrid from S. nemorosa and pratensis, abounds
in dry meadows all over the low country south of Vienna. It is an un-
dulating country, with elevations of boulders and clay. On the rising
ground and gentle slopes, S. nemorosa is the prominent feature, but in
hollows of black earth and humus S. pratensis luxuriates. The two
kinds of habitat pass into each other gradually, those common to both
consisting of dry meadowland in which the former parent does not
thrive, and is seldom seen, while it is too dry for pratensis, which is also
poorly represented. But the hybrid, being intermediate in character,
thrives there exceedingly ; is much visited by insects; and ripens seeds
as well as either parent, of which experiment has shown that 60 per cent.
are fertile. Thus the hybrid, which is scattered all over this meadow-
land, manifests all the characteristics essential to our conception of a
species (p. 588).
Nuphar intermedium, a hybrid from N. lutewn and pumilum, occurs
in lakes in the Black Forest and in the Vosges, in scattered localities of
North Germany, Central and North Russia and Sweden, and as far north
as Lapland, in the north being more abundant than either parent—in fact
it passes their northern limit, and occurs without them. Here it multiplies
from seed without change of form, and in fact has established itself, to
all appearances, as a species; yet its origin has been proved by artificial
crossing. The reason why the hybrid has been able to extend its range
further north is that it matures seeds in rather shorter time than either
parent, and thus we may say that the northern limit of each is deter-
mined by its ability to ripen its fruit. N. /uwtewm flowers last, and is the
last to ripen its seeds; consequently as we proceed northward we find
that it is the first to fail. NN. pumilum ripens a little earlier, and conse-
quently gets a little further north, while V. intermediwm is able to extend
itself beyond either. As, however, hybrids can only occur where the
parents grow together, it is clear that the extension of N. intermediwm
northwards beyond the limits of N. lwtewm has been by its own seeds,
and there at all events it is autonomous (p. 589).
Sometimes a hybrid is fonnd in company with one parent only, or
with one in one locality and both in another ; sometimes even where both
are absent; and this may either be due to diffusion from the original
birthplace, or, in some cases, to displacement of the parents by changed
conditions. In fact, a hybrid which is fertile with its own pollen may
easily extend its range if conditions are favourable, and thus originate a
hybrid race, which, as we have seen, may present all the essential charac-
teristics of a species. Ido not, however, propose to call them “ species.”’
They have certainly not arisen by divergence of character, but rather by
the sudden fusion of essentially distinct branches, forming points from
which new branches may themselves arise. Here, then, is a new factor in
the branching of our genealogical tree, or, at all events, one which has
as yet only been very imperfectly realised, and it emphasises the import-
ance of the subject under discussion to all systematists who wish to go
beyond the mere identification of their plants.
To what extent, then, does hybridisation occur in nature? Kerner
estimates that something like a thousand natural hybrids have been
found in Europe during the last forty years, and there is no reason to
202 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
suppose that this Continent enjoys special facilities in this respect. Floral
contrivances for promoting cross-fertilisation lead. to a constant trans-
ference of pollen, for we know that insects in their search for food are
indiscriminate in the flowers which they visit, and this circumstance
leads to a constant origination of hybrids wherever allied species capable
of intercrossing grow in close proximity. Their production is largely a
question of opportunity, for,as we have already seen, some have originated
spontaneously in gardens where allied species from different localities
have been planted together. And there is Hrigeron Hubseni, a remark-
able wild hybrid which has originated between the European perennial
E. acer and the introduced annual EH. canadense, which furnishes an
excellent example.
Of these hybrids only a fraction survive and multiply. In the first
place they may be sterile, or if fertile they are liable to he swamped by
recrossing with the parent stocks. They may even be less suited to the
conditions under which they find themselves than either parent. The
establishment of a hybrid race is dependent on certain circumstances. It
must be fertile with its own pollen—that is with pollen of the same
hybrid stock—and it must be in harmony with the conditions of its
habitat. It has to enter into a struggle with the species already there,
and particularly with its parents, and only if as well or better fitted to its
environment will it make successful headway. In a few cases, as we
have already seen, it may grow apart from either parent, and encounter
new conditions of soil cr climate which specially favour it. Under such |
a combination of circumstances hybrids may become dominant, yielding
hybrid races.
Viewed from this standpoint the phenomena of hybridisation acquire
a special significance to the systematist, and a knowledge of the behaviour
of artificial hybrids under cultivation, and the relation they bear to their
parents, should help him greatly in the identification of those which
occur spontaneously in a wild state. And a correct idea of the existence,
behaviour, and distribution of natural hybrids where their life is un-
trammelled should throw further light on the very origin of species. We
need not follow the subject into the regions of pure speculation, but if
hybrid races exist in the present they may have done so in the past—a
nice little problem for speculative geologists to tackle.
A knowledge of garden hybrids, however, will not enable us to under-
stand or recognise all those which occur in nature, and various problems
will have to be investigated by direct experiment, the results of which
will throw further light on a most important but perplexing and intricate
subject.
I think I have said enough to vindicate the opinion of Dean Herbert,
expressed over three-quarters of a century ago, that hybridists would not
confuse the labours of systematic botanists. Indeed, in the words of Mr.
C. C. Hurst, “ artificial hybridisation, which it was supposed would lead
systematic botany into the direst confusion, by the irony of fate.seems
destined to be the only trustworthy means of saving systematic botany from
its own confusion, and the systematist, however orthodox he may be, can
no longer afford to ignore artificial hybridisation.” The foregoing facts,
I think, fully warrant the conclusion.
ON SOME HYBRID POPPIES. 203
ON SOME HYBRID POPPIES.
By Monsieur Henry DE VILMORIN.
THE series of hybrid Poppies, of which I purpose to give a short account,
originated at Verriéres, near Paris, in the year 1890, in consequence
of a cross repeatedly performed between Papaver bracteatum, L., seed-
bearing parent, and a double garden variety of P. somiiferwm, L., which
supplied the pollen, a striking feature in the case being that one of the
parents is an annual and the other a perennial plant.
The great discrepancy in the respective characteristics of both parents
affords an easy means of recognising the fact of the blending of the
species and of appreciating the relative share of influence of either
parent in each individual hybrid plant.
The first batch of seedlings raised from the original seed-pod showed
a very remarkable uniformity of appearance. All the plants were annual,
with a distinctly glaucous colour on leaves and stems, plainly inherited
from P. somiuferwm. From the same parent they derived their branch-
ing habit. From P. bracteatwm they received the strong hairs on their
stems and leaves and the great size of their flowers, which were con-
stantly single, and showed variation only in the fact of some of them
having the edge of the petals fringed or laciniated, while in the greater _
number it was plain and smooth. The colour was a deep rich crimson,
with a dark blotch on each petal, the influence of the common annual
Poppy asserting itself again in the departure from the fiery scarlet of
P. bracteatum. In height the hybrid plant surpassed both its parents.
The plants in this first generation bore no seed.
A fresh trial was made in 1892 with seeds kept over from the original
capsule. They came up freely, and several beds were planted with the
seedlings, which developed into plants quite similar to those raised the
year before. A few plants showed some tendency to take a perennial
habit. Some seed was saved this time, although in very small quantity,
and from the annual plants only.
This became still more marked in the next generation, when some
plants visibly reverted to P. bracteatum, but were found entirely barren,
while the annual plants, with the plain stamp of P. sommferwm upon
them, commenced to set seed more freely.
From the first some slight variations were observed in the colour and
shape of the flowers, which, by selection, were brought to reproduce
themselves in a fair proportion. Roughly speaking, one might divide them
into three sections :—
(1) Bright crimson, the original shade of colour, with large,
strongly marked black blotches ; single.
(2) Light, delicate pink, with the blotches much less distinet
than in No. 1; single.
(8) Double flowers, never very full, but showing a bunch of
entangled narrow petals in the centre, not concealing the broad
blotched outer petals.
204 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Such are for the present the principal variations issuing from the
hybrid Poppy just mentioned. They are all annual, and partake more or
less of the glaucous colour of P. somniferwm. They were introduced into
trade collections in 1895, and are useful as showy annuals.
But a new departure was recently effected by pollinisation of the
original hybrid plant by a distant race of the maternal P. bracteatum,
known in gardens as the Tournefort Poppy, which differs from P.
bracteatum by the absence of the leafy bracts under the corolla and by an
orange scarlet instead of a deep blood colour.
The effect of the new cross was to bring back the plant to a perennial
habit of growth ; to breed the glaucous colour out of it to a great extent,
while retaining the branching character of the stem. A perpetual
growth of flowering stems was also induced, in consequence of which the
new cross promises to be a valuable hardy plant for the garden, being a
perpetual bearer of large bright flowers during all the summer and
autumn. It is quite hardy, and being planted out in September stands
the winter perfectly, and blooms profusely from May till October. The
colour of the flowers is a bright scarlet, somewhat verging to orange, with
petals either plain or blotched : they are large and showy, but naturally
rather smaller in the more branched plants.
Some other crosses were attempted, mainly with P. piloswm, Sibth.
and Sm., and P. glaucuwm, Boiss., which were manifestly successful,
but up to the present day failed to produce seeds, and are consequently
confined to the domain of botanical curiosities, while both the annual
and the perennial forms of the hybrid Poppies just described may hope
for a successful career amongst the objects of ornamental gardening.
The CHarrMAN: I am sure everybody here will thank M. de Vilmorin
for his important communication. As he observes, a cross between two
species, one perennial and one annual, is of great rarity and of particular
interest. The attempt at crossing between Sunflowers, one perennial and
one annual, some time ago was a complete failure. ! do not know
whether it has since succeeded.
M. pre Viumorin : I may add, several other crosses were attempted with
different kinds of Poppies, but only in this one case | came to a definite
result, and obtained something that might be of interest and use. Most
of the other attempts failed in the sense that they gave no seeds by which
to reproduce the hybrid. From many of those we crossed we obtained
plants, but plants that were entirely barren. .
The Cuarrman: We still have half-an-hour, and it is suggested that
we should have a general discussion, not limiting our remarks to anything
we have heard at the Conference, but taking in any point that may strike
any member. If you will allow me I will start the ball with a few
remarks. I would make an observation upon photographs of the micro-
scopic structure of hybrids. Perhaps many persons have seen Dr.
MacFarlane’s drawings showing how you get a strict intermediate. Just
now Dr. Wilson told us it was a difficult thing to study them where you
got complex hybrids. Dr. MacFarlane only dealt with primary hybrids.
I have studied those Rhododendrons which Mr. Veitch has raised, and went
minutely into them and examined them microscopically. But nothing
DISCUSSION. 205
came of it. There was not a single feature showing any structural
difference between any two. Perhaps there was a little difference in the
fibre of the vascular stock, but nothing like Dr. MacF arlane’s illustration.
I think the remark of Dr. Wilson’s holds good where species are alike in
their structures. We note that species differ if they come from widely
different localities. A species growing in the desert or in Alpine regions
compared with one growing in marshy land exhibits a wonderful
difference. Where you get plants from widely different localities you
expect to find these differences well pronounced in the microscopic
structure. The Rhododendrons I examined all came from the same
district, and there was no difference that I could discern in their anatomy.
Yet some of them contained four or five species, and were very compli-
cated in their structure.
Mr. F. W. Bursipce: Before we close this most interesting Con-
ference it would perhaps be advisable if we entered to some slight extent
into the question of the nomenclature of hybrids. When we held the
Narcissus Committee—in 1884, I think it was-——there was a resolution
passed that the plants should not receive Latin names. We all know
that the adoption of Latin names for hybrids has been a source of
extreme trouble from the very first commencement of plants being
hybridised. In olden days they raised Calceolarias, Pelargoniums,
Fuchsias, &c., and they all got Latin names. The consequence is that
to-day you find these names in botanical books, and the parentage is
kept back, and the consequence is that utter confusion exists. We really
do not know a tenth part of what we ought to know of the hybridisations
of the past, owing to the Latin names being used in the same way for
hybrids as for real species. Dr. Masters some years ago struck a very
good note when he named a hybrid, raised by Mr. Veitch, Philageria—a
compound of the names of the two genera that were united in the cross.
The same plan is now carried out in other places. Sir Michael Foster was
lucky in hybridising Iris, and very often he adopted the two specific
names or a portion of the two names. Iris Monspur was a cross between
I. Monnieriand I. spurius. To a certain extent this principle works fairly
well; but I really think that we should go further to the root of the
matter, and do away with the Latin names altogether for hybrid
and garden plants. I think if we passed the resolution adopted by
the Narcissus Committee, only making it apply to all plants, we should
meet the case.
The Rey. G. H. ENanueHEART: There is one subject of very practical
importance that has not been touched upon at this Conference, but which
ought to receive some attention. One feels that the subject of hybridisa-
tion is so enormous that at a Conference of this sort, even of two days’
duration, one cannot possibly traverse the whole ground. I think it may
be well just to hint at a line that may be taken up on a future occasion,
and which I think would be of great practical value. Dr. Masters showed
us very lucidly in opening the Conference that this was an era of hybridi-
sation. Nowadays plants are made. And we know that life is short,
and that the art of hybridisation is very long indeed. When the gardener,
the practical man, establishes a business—the man whose money is in
his gardening—he feels a certain reluctance to attack plants of which he
206 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
will not see the bloom, or the fruit, or the pecuniary recompense. It is,
then, all important that the gardener, both the amateur and the profes-
sional—but the professional especially—should have every assistance ;
assistance, | may say, internal and external, equipment all round, and
in the best way for the furtherance of his work. To begin with, we very
much want something in the form of an easily intelligible handbook, which
shall summarise the work already done in hybrids, so that every man shall
not have to go over the same ground again. I have found there is an
immense amount of waste of labour. In my own small work I have
found that a great part of my time is wasted ; for if one only knew the results
of what others had done, or if we could only know what statements one
reads are true and what are false, we should save a very great deal of time.
IT remember when I started with Narcissi I got hold of a book that told
me to tie up the trumpets of my flowers to prevent insects crawling into
them. I remember doing this—tying up the mouths of the trumpets.
I never got any seed at all that year. No doubt that is a thing which
should be known. The flower is a very complicated thing, and all its
parts have meanings; and if you tie it up or cut off your corolla, you
probably lose your seed. It would be a great help if these sort of things
were generally known. In reading Darwin’s work on cross-fertilisation,
I was very much struck with one phenomenon. In one of his experi-
ments with Dianthus he found the strain lost vigour and reproductive
power. He crossed it then with a plant from his own garden, and the
strain began to recover tone and strength. Then he went further, and
crossed this variety with a plant from a distance, and he found that the
infusion of blood from a distance gave still greater freshness and vigour.
He got more seeds and stronger plants. Fortunately for myself I acted
upon that, and I could see quite distinctly the good of putting fresh
bulbs from a distance into my ground and writing to my friends at a
distance for pollen. If we had a little handbook where these notes could
be published, it would bea great help to us. It is very difficult to glean
here and there from the pages of newspapers the information one requires.
Here is another practical suggestion. Supposing a man who lives on his
nursery raises, we will say, a good Peach, and a year or two after, when he
has a good stock of that Peach, there comes a pecuniary pinch, and he
has to sell his stock. He sells his stock, makes £50 or £100 by it. How
much is it needed that a man should have some sort of patent rights
during his lifetime in the fruit of his brain and industry! It is very hard
that a man should be able to write a book and draw an income from that
book, but that if he produces a plant that enriches the garden, or orchard,
or nation, the year after he has produced it it is all over the kingdom, and
everybody has as much gain from it as he has.
Mr. Georae Paun, V.M.H.: I should like very much to fortify what
Mr. Engleheart has said. I do think it is a very hard thing that when
we look round and see the work our English and foreign hybridists have
done to feel that the work is so unremunerative. Perhaps in fruits it
tells more, because these are articles of more commercial value. Take
the Cox’s Orange Pippin, an Apple to be found in every fruit garden in the
world. The man who originated the Cox’s Orange Pippin, I believe, did
not make a penny out of it. I can speak with personal knowledge, having
DISCUSSION. 207
been a raiser of Roses. I have communicated with others and have found
that for all our trouble as Rose raisers our practical benefit has been almost
nil. We have worked for honour and glory. That no doubt is a great
thing. It is a grand thing to have your name handed down as a bene-
factor of the human race. But if the same pains, the same work, the
same intelligence, had been given in any other profession or trade, in all
probability men who had done equally good work would have reaped
considerable pecuniary reward. I think the time has almost come when
the Legislature should give some form of protection to the producers of
such good things. I certainly think the labourer is worthy of his hire.
I have talked it over with others, and it does not seem to me impracticable
that some form of protection should be given to the man who has raised
and distributed a new plant. He should have at least two, three, or four
years of protection. It is a right given to other people—the right of
private manufacture. A man who makes a screw which twists a trifle
easier is protected by the Legislature, which gives him for many years the
sole right to make that screw himself, or to receive payment for allowing
other people to produce it. Jam very glad that the original suggestion
on this matter came from a man who has no interest in the trade like
myself; but I have felt it so keenly, and I am sure that other raisers have
also, that it seems to me at the end of a Conference such as we have had
it was fitting that the subject should have been introduced. I, person-
ally, as a raiser and a tradesman, thank Mr. Engleheart very warmly.
Mr. Georce Bunyarp, V.M.H.: Mr. Engleheart has introduced a
subject which, of course, is of very great interest to all of us, and he hag
started a discussion on the commercial aspect of horticultural questions.
I am not a botanist; I am not a scientist; I am acommercial man; and
I think the whole thing lies in a nutshell. It surely remains with the
person who raises a thing to sell it at his own price. It seems to me a
very simple thing. Say that I raise a new Apple ; it seems to me as easy
a thing as can be if I want to make £100 out of it that I should raise a
sufficient stock which at 5s. apiece will bring me in that amount. All I
should have to do would be to say, “I have brought out a new Apple. I
am willing to distribute it at 5s. a piece, and I do not intend to let it go
until I have sufficient orders for it to pay me for my trouble.’”’ The idea
of having patent rights in a thing that can be so easily and readily pro-
pagated seems to me not only in the highest degree improbable to be
attempted, but impossible to be secured by any legislative action. What
power can possibly prevent distribution? A head gardener might throw
a cutting or a root on a rubbish heap and his assistant might go and
give it toa friend. You cannot follow it up and prevent it. The subject
has frequently been discussed between Mr. Rivers and myself. I told
him, “ You have been disinterested almost to the point of folly ; you have
practically given away plants of enormous commercial value.’’ But he
could not blame me. I had bought the things of him, and I had given
him whatever price he asked forthem. The remedy is to put a sufficient
price upon a new plant when you first part with it; and on those lines
the whole thing seems to me a yery simple commercial matter, requiring
no patent rights whatever, save those which each man can manufacture
for himself.
208 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Dr. Masters: When I had the honour of opening this Conference
yesterday I told you we were about to discuss a most important subject.
I am sure you will agree with me that I was right. I told you also there
were a great many difficulties and knotty problems. We have taken a
survey of a wide field to-day and yesterday, and have even ended by con-
sidering trade rights and patent rights and copyrights. I think the out-
come of our Conference is this: There are difficulties to be solved. There
is a difficulty in reconciling the practical man and the purely scientific
man. But I would ask of all present whether we have not solved it.
They have only got to ‘“cross,’’ and all our difficulties will be solved.
Mr. Wiuuet M. Hays, U.S.A.: I do not know that there are others
here who represent experimental stations, but I believe the time has come
in America, and will come in other countries, when the experimental
station shall take up this question of the sending out of new plants as one
of their duties. The originator then will get a chance of having his
creations placed before people at a proper remuneration to himself.
I should like to ask whether we are going to continue the delightful dis-
cussions of the last two days at some future time and at some other place.
Are you going to France next year, or will you come over to America ?
I feel a little delicate about suggesting these things, but if you would
come to us I would promise you a right-down hearty welcome.
The CHarrMAN: With reference to the subject opened by Mr.
Engleheart, I have not a word to say, being a scientist pure and simple. I
see the difficulties, although perhaps Mr. Bunyard’s suggestion may settle
it. When you start a new plant and spread it about in the country it
very often changes its characteristics slightly in different localities, and
if propagated from that locality it would not be exactly the same plant as
that from which you started. How far you would be able to guarantee
the same form, or to prevent the distribution of the slightly different local
form, it would be difficult to say. Before concluding, I think we must
thank those gentlemen, especially those foreigners who have come so
long a distance to help us, for the interesting papers they have given us.
When we get the papers printed in our Journal we shall be able to
study them at our leisure. How far it will be desirable or practicable to
carry out a Conference in another country—whether in Germany, France,
or America—it is impossible for me to say at the present time; but it is
a suggestion worth thinking about. I beg to thank you all in the name
of the Royal Horticultural Society.
HYBRIDISATION IN THE UNITED STATES. 209
COMMUNICATIONS SENT TO THE CONFERENCE.
HYBRIDISATION IN THE UNITED STATES.
By Professor L. H. Batney, Cornell University, Ithaca, U.S.A.
In considering the status of hybridisation in any country two courses
are open to the reviewer. He may make an inventory of the specific
experiments in hybridisation with discussions thereon, or he may
attempt a bold summary of the results. One is the method of details ;
the other is the method of conclusions. It is this latter method, I take
it, which your Secretary had in mind when he asked me for a short
paper on hybridisation in the United States. I therefore attempt, with
few sentences, to express judgment upon the progress of hybridisation
in this country, upon the present status, the tendencies, and the
prospect.
It is first of all necessary that the European reader should know that the
standards of judgment are unlike on the two sides of the Atlantic. This
is because the natural and economic conditions are unlike in the two
continents. Relative to the entire area, intensive gardening is less fre-
quent in America thanin Europe. There are, relatively, fewer glass-
houses. There is less interest in individual plants. There is less of the
amateur’s instinct. On the other hand there is, relatively, more large-
area horticulture. Fruit-growing has developed farther than elsewhere
in the world. There is relatively greater interest in cosmopolitan varie-
ties—in those which are adapted to wide ranges of conditions. It is
therefore evident that there must be less interest in hybrids merely because
they are hybrids; for hybrids are valued most where there is the greatest
number of fanciers, or the most persons who grow plants for the intel-
lectual interest in the individual specimen.
Again, the interest in individual plants is gratified in small gardens,
in which the conditions are under control. The varieties of Europe can
be grown in these gardens. Glass and water and shade and highly
fertile soil and skilled labour will grow almost any plant. Our taste for
the choice horticultural rarities and curiosities is supplied very largely by
varieties of European origin. We buy your hybrids, and Iam sure that you
would not have it otherwise. The highly bred Cannas, Tulips, Roses,
and many other plants are as frequent and as good in American gardens
as in European; but the greater number of them are of Kuropean
origin.
Our great problem is to make the country productive. There are as
many different climates and physiographical conditions in the United States
as in the whole of Europe. The plants must grow in the sun and the
rain and the drought, and be able to hold their own. ‘There are great
stretches adapted to fruits and vegetables and flowers. These areas must
P
210 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
be filied. In this you cannot help us, except in so — as you give us the
orginal stock upon which we are to work.
It isin the development of great new races of fruits that the American
has made immense strides a plant-breeding, and some of this breeding
has been by means of hybridisation. How great this experiment has
been we ourselves have not realised; but it is certainly beyond contra-
diction to say that the last fifty years have produced greater results in the
breeding of fruits in America than has ever been witnessed in the sama
length of time. These experiments have been on so large a scale, and
the results have been so far-reaching, that they almost eclipse the many
attempts at the production in this country of mere hybrid plants.
Our fruit growing may be said to be endemic. The European type of
Grape (Vitis vinifera) is grown in California and some other places; but
the Grape interest of the larger part of North America is developed from
our native species. Great numbers of the varieties are hybrids, some of
them between the native species themselves and others between the
natives and the European or Wine-grape stock. Many of these hybridisa-
tions were undesigned, but there are notable exceptions. » Several
experimenters have made direct attempts at the amalgamation of the
species, and each one has had a distinct and personal ideal. The
eastern hybridists have sought to introduce the Wine-grape blood into the
native stock. Of such are Rogers, Haskell, and Ricketts. Some of
Rogers’ hybrids are now amateur and commercial Grapes of high stand-
ing, as the ‘Agawam,’ ‘Lindley,’ ‘Salem,’ ‘ Wilder,’ and ‘ Barry.’
The western hybridists have sought a closer amalgamation of native
species and varieties, although most of them have used more or less
dilute Wine-grape blood. Jacob Moore has produced the ‘ Diamond,’ a
Grape of much importance and promise. Rommel and Jeger and
Munson have worked with the species of the mid-continental region ; and
Munson, in particular, has bred with the excellent and variable Vitis
Linsecomi of the post-Oak regions of the south-west. Wylie has
attempted the amalgamation of the southern Muscadine (Vitis rotwndi-
folia) with the northern types. Waugh has estimated that 42 per cent.
of our varieties of native Grapes are hybrids or crosses. There are
certainly more than twenty native species or varieties of Vitis in the United
States, and several of them will unite to produce the Grapes of the future.
While the Grape has been the most prolific field of hybridisation
experience in the western world, it is difficult to say what fruit occupies
the second place in this respect. The most marked departures have
occurred in the Plums, but the results are not yet of such commanding
commercial importance. The European type of Plum thrives from the
northern Allegheny region to the Atlantic, along the Great Lakes, and
on the Pacific slope; but in the wide continental plain and in the South
it finds only a precarious existence. In this great region there are
several native species of Plums, and two or three hundred cultivated and
named varieties have already arisen from them. Many of these varieties
are of hybrid origin. In fact, there is a whole class of hybrid Plums
which is so unique that the group has been described as a species,
Prunus hortulana. To this class belongs the ‘ Wild Goose Plum,’ which
is a staple variety in the interior country. ‘The Japanese Plums (Prunus
HYBRIDISATION IN THE UNITED STATES. PA i |
triflora) have become widespread and popular within the last thirty
years; and now a new race of hybrids between these and the natives is
appearing. Thirty undoubted Plum hybrids have been studied and
tabulated by Waugh, and as many as seven species are represented
in them.
A somewhat parallel evolution is taking place in Apples. The Prairie
States Crab (Pyrus Ioensis) has hybridised with the common Apple,
producing a race which has been described as a species. These hybrids
promise something for the mid-continental region. But perhaps the
largest crossing experiments ever made in North America is in the
amalgamation of various races and varieties of Pyrws Malus, in the hope
of securing adaptable varieties for the western Mississippi valley and the
cold North. The Russian races and the Siberian Crab (the latter, Pyrws
baccata) are some of the stocks which have been used. Budd long ago
began this crossing work, and some of the seedlings are now bearing at
the Iowa Agricultural College. To give an idea of how extensively this
work is prosecuted, I may say that Craig made over 5,000 Apple crosses
in Iowa in 1899. For one thing a man was sent to Arkansas, a distance
of 500 miles, to collect pollen of given local varieties, and this was used
on the Iowa flowers. This work is systematised between the Iowa
Experiment Station and the fruit growers of the State.
The European Pear does not thrive in our Southern States. But a
new race has made Pear growing profitable there. This race is the product
of several hybridisations of Pyrus communis and Pyrus Sinensis. Of
this race two varieties, the ‘ Kieffer’ and ‘Le Conte,’ are widely planted.
The acres upon which they are planted are counted by the tens of thou-
sands. The ‘ Kieffer’is now the leader. It is a poor Pear in quality, but
it is immensely productive, handsome, and a long keeper, and it sells
well in the open market. This mongrel race has made Pear growing
possible over an immense region. It must rank as one of the great
hybrids of the world.
Our large Orange interests are on a European foundation. But the
trees are not sufficiently hardy. For the improvement of the Orange in
hardiness very significant experiments have been begun by Webber and
Swingle, of the National Department of Agriculture, in amalgamating
Citrus aurantium and Citrus trifoliata. The results are promising ;
and it will not be a surprise if the next great advancement in fruit-
breeding is made in this direction.
There are important hybrid races in Raspberries and Blackberries, and
in several other fruits.
The establishment of the experiment stations twelve years ago gave
an impetus to the study of plant-breeding problems. The number of
experiments is very large, when considered in the aggregate, but it is yet
too soon for measurable results. Some of the efforts in plant-breeding,
in which crossing is playing an important part, are those on the Apple
by Craig in Iowa; on the Plum by Waugh in Vermont; on the Orange
and Pineapple by Webber and Swingle; on Maize in Illinois and Kansas,
and elsewhere ; on Cotton in Georgia and Alabama; on Strawberries at
the New York State Station and elsewhere ; on Wheat in Kansas, Min-
nesota, and elsewhere ; on cucurbitaceous plants at Cornell; on many
Pp 2
219, JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
fruits at Ottawa and other places in Canada; and in many other direc-
tions by various experimenters. Various private individuals, as Munson
and Burbank, are making useful experiments along similar lines and
on a commercial basis.
Another fruitful class of experiments, although not strictly hybridisa-
tional, are those which have to do with the influence of crossing upon the
set of fruit. Studies in this direction have proceeded far in America,
having been set on foot by the investigations of Waite and Fairchild.
While pomological interests are paramount and often unique, distinct
advancement has been made in many other types of plants. The most
notable example is the carnation. The winter or forcing carnation or
clove pink (Dianthus Caryophyllus) has developed into a new type in
North America, and the evolution has come about within a generation.
An important part of this progress has arisen by means of crossing.
Other flowers have received attention from the hybridist, but in no other,
so far as I know, has the American established a well-marked and domi-
nant race.
In nearly all these instances hybridisation has been a means rather
than an end. It induces variation. It is the beginning of plant-
breeding: selection is the continuation of it. This is a fundamental
principle. Hybridisation is not an art, distinct in itself, but is, or should
be, one part or step in plant-breeding processes. In the case of fanciers’
plants it is of less importance than in fruits, for a few plants satisfy the
demand. Taken in a large sense it is immaterial whether the variation
is originated by means of hybridisation or otherwise. The variety is its
own justification. In the varieties produced by the private plant-
breeders the public must be content to judge by the results, for the data
of their origin are not often given. Hybridisation seems to be a magic
word, and many of the new varieties which are attributed to it in this
country are only seedlings of ordinary parentage. The laws of plant-
breeding are to be worked out in the United States by the officers of the
experiment stations. For the moment most of these workers are
engrossed in the details of the business. Only two or three philosophical
essays have appeared ; but perhaps this is a sufficiently high proportion.
The foregoing review of experience suggests the tendencies in
American plant-breeding efforts. The controlling tendency is to develop
plants which are adapted to our native conditions; secondarily is the
tendency to develop varieties to satisfy individual or personal desires.
It is to be expected that as the general or national demands are satisfied
the specific and personal demands will come to be more prominent.
More and more, as years go by, will the EKuropean-bred varieties be used
as bases for further breeding, rather than as perfected commodities in them-
selves. From time to time a race will come to be so distinctly developed
in America that the European stock will no longer be needed. This has
already occurred in the Carnation and the Chrysanthemum. Yet I hope
and expect that the time will never come when the American loses
interest in any novelty which the European brotherhood may produce.
We must continue to draw, not only hybrids, but knowledge of hybridism
from European sources.
There is a decided tendency to utilise our native species in the
HYBRIDISATION IN THE UNITED STATES. a3
development of ornamental plants, as we have in the development of
fruits. Nearly 3,000 native species are now in cultivation as ornamental
subjects. Already there is amalgamation of types, but it is evident that
the process has only begun. It is possible that we may be able some
day to offer the European gardener something of interest.
The greatest work of the hybridist is the development of tendencies
and races rather than varieties. The slow and repeated amalgamation
or blending of types is the consummation of plant-breeding. The pro-
duction of a single hybrid which may be named and sold brings more
present glory, but it is only an isolated fact. The best results come
when species have been so completely blended that we cannot say which
are hybrids and which are not.
Fie. 103.—Zyeoconax Verrcut. (Journal of Horticulture.)
(CoLox sucosts « ZyGoprraLtM MacKAYy!I CRINITUM.)
214 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
ON SELF-STERILITY.
By Professor Dr. F. Lupwie, the University of Greiz, Germany.
For years I have devoted particular attention to those plants which
are sterile when pollinated with their own pollen, and have discovered
that self-sterility is far more prevalent in the plant kingdom than has
hitherto been imagined; that this, and not an entire loss of sexuality,
is the cause that many species of plants in extensive districts or on an
entire continent never, or scarcely ever, form seed; and, finally, that
within the same species self-sterile individuals may be found in one
place and self-fertile ones in another. Some of my observations and
experiences are as follows.
Self-sterility I have found to occur with special regularity in the case
of such plants as propagate themselves vigorously by means of rhizomes,
offsets, or bulbils. The numerous plants which, in the course of years, I
have raised from one individual—in the case of Symphytum bulbosum,
Dentaria bulbifera, Apocynum hypericifolium, A. androsemifolium,
Cypripedium Calceolus, &e.—never set seed in my garden, despite the
presence of their proper pollen-carrying insects, and despite artificial
transference of the pollen from bloom to bloom. When, however, in the
case of Apocynum hypericifolium and A. androsenufoliwm, 1 brought
plants into the garden from another source, the seed ripened. Jt is
known also that Dielytra spectabilis, Lysimachia numnvularis, and other
plants are mostly propagated asexually, and then remain infertile. With
Ficaria verna, which Schulz found to be gynomonecious, and Delpino
gynodicecious with smaller female flowers (gynodimorphic),* and espe-
cially from the results obtained by Herm. Miller, who raised normal seed
capable of germination from a bulbil-bearing plant, there can scarcely
remain a doubt that the infertility springs from self-sterility, and that
this can be removed if pollen from a foreign, that is, a physiologically
independent, individual be applied. The individuals which are found to
occupy one habitat probably spring, as a rule, from one and the same
physiological individual being propagated through the free multiplication
of the plant by epigceous and hypogeous bulbils. Delpino counted on
one plant fifty-four hypogcous and twelve epigceous, and on another of
the female form 124 hypogeous and seven epigceeus bulbils. The same
may be said of our European Acorus Calamus, the examples of which,
throughout extensive districts, only represent one and the same physio-
logical individual, owing to their exclusive propagation by the rhizome.
Seeds have not been observed in Europe so far, as the plant is self-
sterile; in America, however, the seed ripens not infrequently, and I am
firmly convinced that by planting American plants in our waters the
European Calamus would have its fertility restored. Some five years
ago I planted the American Calamus in a pond near Greiz: it has spread
* « Dimorfismo del Ranunculus Ficaria. Memoria letta alla R. Accademia delle
Scienze dell’ Istituto di Bologna nella Sessione dell’ 11 Aprile 1897.”
-
ON SELF-STERILITY. 215
vigorously, but so far, unfortunately, has not flowered. It is to be hoped
that by its aid I shall succeed in rendering the European race a fertile
one.
How far the signification of the self-sterile physiological individual
should be carried, I learn from a letter of my late friend Dr. Fritz Miller,
at Blumenau, in Brazil, dated January 24, 1895, referring to my com-
munication regarding the planting of the American Calamus. For some
years a beautiful Amaryllis, which is plentiful in the gardens about
Blumenau, and which morphologically constitutes the offspring by bulb
propagation from a single imported individual, has been observed to be
entirely sterile. In 1884 Fritz Miller found the species growing wild
near the sea, and crossed with individuals from this source, the garden
form became fertile. A still more striking example of self-sterility is
seen in Hedychiwm coccineum. The morphological individuals of the
species are quite sterile between themselves, although the pollen is
normally developed, and the species, united either as male or female,
forms hybrids with kindred species of the same genus. Some years since
Fritz Muller received Hedychiwm coccineum from Buitenzorg, among
other Zingiberacee, and crossed numerous flowers of the plants—
which had certainly been introduced into Brazil more than a century
before—with these Javanese individuals, but without any results. He
concludes, therefore, ‘‘ that the individuals raised both in Brazil and in
Java as decorative plants came from one and the same garden, into
which a wild plant had originally been introduced.”
Iam much encouraged in the hope that I may restore fertility to the
Kuropean Calamus by the following, in many respects, instructive attempt
with Trientalis europea.
I am acquainted with three quite isolated stations of this plant in the
woods round Greiz, isolated but very extended, and far from any others.
These, together with other relics, may have existed (according to Aug.
Schulz) since the fourth of the Ice periods which are to be distinguished
in Thuringia.* In any case, these stations have been occupied from time
immemorial; and it appears, moreover, that at the present stations
all the plants spring from the same rhizome, and have only propagated
themselves by means of the rhizome because they are self-sterile, and for
more than twenty years I have sought in vain to find a single seed
capsule. At .a distance of about four geographical miles Trientalis is
found in quantity, and I brought examples from Struth at Niederpéllnitz
in 1895 for observation in my garden, where they were fertile both with
their own and with foreign pollen. In 1895 I planted four, and on
March 29, 1897, some more examples from Struth among the self-sterile
form in the Kriimmthal, near Greiz, where annually thousands of self-
sterile examples flower, and marked the places. The result was as
expected. Kven in 1895 I found not. only on the introduced plants, but
also on several of the old indigenous form, well-developed seed capsules,
which also came to maturity. In 1898 I found about fifty ripe seed-
vessels. The rejuvenescence of the race, self-sterile for ages, had thus
been successfully effected ; and the Calamus must, I think, also succeed.
* « Grundziige einer Entwickelungsgeschichte der Pflanzenwelt Mitteleuropas seit
Ausgang der Tertiarzeit,’’ Iena, G. Fischer, 1894.
216 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
If, on the one hand, self-sterility is specially emphasised where extra-
ordinarily vigorous asexual reproduction narrows down the likelihood of
separate physiological individuals appearing, as in the case of Symphytwm
bulbosum, which, by offsets and their distribution, overran the whole of
my garden in a few years; on the other hand, it particularly occurs, or
even arises anew, where, with perennial plants, the prospects of cross-
pollination seem specially secure.
Examples of this are seen in Hrodiwm macradenum, E. pimpinelli-
folium, and others. Of the first, I had in my garden two very floriferous
plants raised from seed, which were fully adapted for cross-pollination
by insects * and bore seed. In 1881 one of these, being planted out
earlier, flowered several weeks before the other. The numerous umbels
which were developed at this time did not set a single seed, despite self and
general pollination; whilst after the flowering of the other plants
numerous flowers were xenogamously fertilised. When later one of the
plants died, the other, it is true, flowered annually, and developed an
extraordinary floriferousness (anthomania), but never produced another
seed.
Hrodium cicutariwm is self-fertile. The insect-flowering form of E.
pimpinellifoliwm, with large flowers and distinct ‘“‘ path-finder,”’ presents,
on the other hand, all stages to self-sterility, parallel with the perfec-
tion of arrangements for xenogamy. ;
More or less regular and effectual insect visits to the various stations
appear also to be the cause of a self-sterile form being coexistent with a
self-fertile one in the case of Daphne mezereuwm. For years I have had a
self-sterile bush of this in my garden, which came from a station at which
bees, Colias Rhamni, and other insects were plentiful. So long as a
second example of different origin grew in the vicinity, both bore and
ripened annually numerous berries. In 1889 the companion plant died,
and since then not a single fruit have I obtained, notwithstanding that
microscopically the pollen is seen to be unaltered, and natural and arti-
ficial pollination occurred among the flowers of the same stock. Twice,
with years intervening, have I brought fresh blooming branches of
Daphne from the wood into the vicinity, so that the numerous insects
might carry foreign pollen to the plant. The result was what I ex-
pected. The self-sterile example of Daphne set its berries, and developed
them further until I removed them. In the years intervening, and after-
wards, the tree remained perfectly barren until its death. Schulz found
in Thuringia Daphne mezerewm self-fertile, and I myself have now a self-
fertile plant in cultivation obtained from stations where insects are absent
or scarce. It appears to me that an example of a step towards self-sterility
is seen in a plant of Helleborus fatidws obtajned from Vernayaz, near St.
Maurice, and possessing effective flowering arrangements. The two fruits,
however, form no seed capable of germination; whilst examples less well
adapted for insect fertilisation, from the Rhone Alps in Germany, form
perfect seed. I have also in this case, for the continuance of the species,
planted examples of both origins amongst each other.
In conclusion, we may summarise the opinions at which we have
arrived in a few short sentences.
* See my work, “ Kosmos IV.,’’ Heft 11, Bot. Centralblatt, 1881, vol. v. p. 298.
ON SELF-STERILITY. 217
1. It has so far been in no case demonstrated that plants of vigorous
vegetative reproduction have entirely lost their capacity for sexual
propagation.
2. On the other hand, such plants can apparently lose throughout
entire districts the capacity for forming seeds capable of germination, when
the flowering individuals are of the same vegetative origin. In fact, how-
ever, they are only self-sterile in the wider sense, and fertilisation can at
any time be again effected by rendering possible foreign pollination by
physiologically separate individuals.
3. Among perennial plants, which do not propagate themselves by
rhizomes, bulbils, or other asexual means, self-sterility very often occurs
with species in which cross-fertilisation appears to be secured.
4, With plants of asexual propagation it appears to increase with the
predominance of the asexual reproduction.
5. In the last two cases named, with viviparous, bulbiferous, &c.
species, and with perennial plants which do not propagate asexually, there
may arise races, within the same species, which are self-sterile and
self-fertile.
6. By introducing new plant species into our gardens, it is therefore
‘always to be recommended, even when the species are hermaphrodite,
homostylic, homogamic, &c., to obtain of each species at least two
examples of as different origin as possible, or to introduce the seed from
such.
218 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
CROSSINGS MADE AT THE NATURAL HISTORY MUSEUM
OF PARIS FROM 1887 TO 1899,
By Monsteur L. Henry,
Inspector of Open Air Cultivation at the Muséum, Professor at the
National School of Horticulture of Versailles.
At the end of April 1894, Professor Maxime Cornu, who had occupied
for two months the Chair of Culture at the Museum, confided to me the
post of Director of Open Air Cultures in this establishment.
I left Nancy where, as Superintendent of Practical Horticulture in the
Mathieu de Dombasle School of Agriculture, and Professor of Horticulture
in the the same school, I was witness of the very remarkable results
obtained by hybridisation by Monsieur V. Lemoine, and had planned
some experiments of the same nature myself.
My nomination to the Muséum was favourable to the realisation of
this project. Nevertheless it could not be carried out for several years.
Before I could find the leisure for it, it was necessary for me to master
the details of the very complicated work of the Muséum, at once difficult
and absarbing, and which, in addition, was being reorganised.
My first personal attempts date from 1887; previously, however, I
had made sundry experiments according to the suggestions and often in
the company of Professor Maxime Cornu, whose advice, as kindly as
it was enlightened, was very valuable tome. At this period M. Cornu
succeeded with several very interesting crosses, notably in the genus
Papaver and the genus Cucurbita.
He had discovered, in a secluded corner of the garden, a very old and
very strong specimen of the old double Lilac, Syringa vulgaris, var. azurea
plena, a variety which, though we did not know it at the time, had served
M. Lemoine for the raising of his first double Lilacs. Professor Cornu
had guessed also what réle this old type was capable of playing ; he
submitted it to crossing, and he was good enough to associate me with
him in these trials. Half-a-dozen capsules were obtained in 1884. But
preoccupations of an altogether different nature,and very pressing, caused
us to lose sight of these capsules at the moment when they should have
been gathered.
The duties and obligations of his post thenceforth did not permit
the Professor, to his great regret, to occupy himself directly with these
crossings. He was good enough to leave the arrangement to me, while
euiding and encouraging me, for which my gratitude is profound.
Many attempts were made during ten years, very often followed by
failure, very rarely by success. ‘They are accurately recorded here in the
hope that this report may be of some utility.
Without wishing at the present time to draw conclusions from the
series of trials, I will only draw attention to the results of our crossing
with Lilacs, themselves derived from hybridisation, but having preserved
CROSSINGS MADE AT NATURAL HISTORY MUSEUM, PARIS. 219
the power of fructification. These crossings, which may be called cross-
ings of the second degree, have generally succeeded much better than
those made direct between specific types, that is to say, than the crossings
of the first degree (see Nos. 7 to 12).
I may be permitted to express a regret—it is that in many cases the
result of our trials has been compromised by accidental causes (excessive
drought in 1893 and in the autumn of 1895; cyclone with hail at the end
of July, 1896), and also and especially by indiscreet curiosity and some-
times by the wilful destruction of visitors (the Jardin des Plantes is open
to the public), and even of certain of our gardeners.
SUGGESTIONS.
It would be interesting, we think, if it were only from the historical
point of view, to endeavour to reconstitute certain plants which are
currently considered as hybrids, but without certain proof of such origin.
It would be a question of establishing this origin in a precise and
indisputable manner, that is to say, to do for these plants that which
M. Lemoine, of Nancy, and I have done for the Varin Lilac (Syringa
dubia) in reconstituting it by means of crossings of the Persian Lilac
with the common Lilac (see No. 23).
The Conference could perhaps organise a series of researches in this
direction. I make the suggestion with that object.
By way of indication I give the following list, necessarily incomplete,
of the plants I have in view. This short list comprises mainly woody
species, with which I occupy myself more particularly.
List oF PLANTS CONSIDERED TO BE HYBRIDS, WHICH IT WOULD BE
INTERESTING TO RECONSTITUTE BY CROSSING.
Amygdalus persicoides (Duham.) Juglans Vilmoriniana (Carr.).
=A. Persico-Amygdala (Daléch.). | Prunus cerasifolia (Hort.)
Aisculus rubicunda (D.C.). =Padus greea (Desf.).
Berberis Neuberti (Hort.) | Pyrus malifolia (Spach).
=B. ilicifolia (Hort.). Pyrus Bollwylleriana (D.C.).
Berberis stenophylla (Moore). | Ribes Gordonianum (Lem.).
Cerasus Fontanesiana (Spach) _ Ribes intermedium (Billiard 1867).
=Prunus greca (Desf.). Robinia Decaisneana (Carr.).
Crategus Oxyacantho-germanica _, Rosa alba (L.).
(Gillot ) _ Rosa Fortuneana (Lindl.).
=C. grandiflora (K. Koch) Rosa Hardyi (Cels).
=C. lobata (Bosc.) Rosa hybrida (Schleich).
=Mespilus Smithii (D.C.). Rosa Noisettiana (Red.).
Cytisus Adami (Poit.). Rubus nobilis (Rgl.).
Dianthus semperflorens (Hort.). | Sorbus hybrida (L.).
Juglans hybrida (Hort.) | Spirea Van Houttei (Briot).
=Juglans pyriformis (Carr.). &e., &e.
22.0 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
REPORT OF CROSSINGS MADE AT THE MUSEUM OF PARIS
FROM 1887 TO 1899.
ORDER FOLLOWED.
Nos.
Woody plants x Woody plants : : ‘ «2 to aa
Woody plants x Herbaceous plants and ees : : . 78to 83
Herbaceous plants x Herbaceous plants . , ‘ ; . 84 to 100
ALPHABETICAL TABLE.
Where the name is followed by a * the crossings have yielded plants.
Where the name is followed by two ** the crossings have not yet
yielded plants, but yielded fruit in 1899, or bore fruit in 1898 from which
the seed has not yet germinated.
Those followed by three *** are those- which have yielded sterile
seeds, or which for any other cause give no hope of germination.
No.
Androsace sarmentosa (Wall.) x Primula veris (L.) . 84
Clematis (hybrids with large flowers) x Clematis Deerinens (Verlot) 78
a‘, viticella (L.) x Clematis Davidiana (Verlot) , : 19
Cratezegus Carrierei (Vauvel) x Cratzgus monogyna re var. flere
roseo (Hort.) : ee
5 cuneata (Sieb. & Zucc.) x Cr tees fhane ore aca, ), var.
flore roseo (Hort.)** . ; . 54
x flava (Hort.) x Crateegus monogyna ( shit ) var. ae roseo
(Hort.)**) : : . O98
as lobata serotina (oe Vix Geaieeus monogyna (Jacq.), var.
flore roseo (Hort.)** . 55
s monogyna (Jaeq.), var. flore roseo x Cr area oxy Praia
germanica (Gillot)** . 56
= Oxyacantho - germanica (Gillot) x “ Ahnyieaeniey maoneee
(Jacq.), var. flore roseo (Hort.) —. ; : . een
Datura meteloides (D.C.) x Nicotiana Tabacum (L. ) ; . 598
Deutzia discolor (Hemsl.), var. purpurascens (Franch. ) x Deutzia
crenata (Sieb. & Zuce.)** . 60
, discolor (Hemsl.), var. parparareen (Franch. ) x Deutzis
eracilis (Sieb. & Zucc.)* p 61
,, discolor (Hemsl.), var. puinpunaseets (Franch, iene
parviflora (Bnge.) ; . 62
Diervilla canadensis (Willd.) x Dservilliss rosea (Walp. yee : ., 68
rosea (Walp.) x Diervilla canadensis (Willd.)** : . 64
Hypericum patulum (Thunb.) x Hypericum calycinum (L.)* . wv BO
Iris acoroides (Spach) x Iris germanica (L.) and varieties : 3) eee
», Delavayi (Franch.) x Iris aurea (Link). : : : oe
,, pseudacorus (L.) x Iris Delavayi (Franch.)** . ‘ Oe
ue am x Iris germanica (L.) and varieties ; . oe
Ligustrina japonica (Maxim.) x Chionanthus virginica (L.) . aes
i s fF x Syringa Bretschneideri (Hort.) EE
” ” 9 x Syringa Emodi (Wall.) . ‘ 2 ao
CROSSINGS MADE AT NATURAL HISTORY MUSEUM, PARIS. 221
No.
Ligustrina japonica (Maxim.) x Syringa pubescens (Turez.) . » 25
i » XSyringa vulgaris (L.) . : . 24
ss pelinensis (Regel) x Ligustrum Thota (Sieb.) ; 7 yee
¥ i » XLigustrum nepalense (Wall.) : $82
* 4 » XSyringa Bretschneideri (Hort.) Pei
E " » &Syringa Emodi (Wall.) . ; + 380
» XSyringa vulgaris (L.)** . ; » 22
Mievebonea [bates (Sieb.) x Ligustrina pekinensis (Regel)** . . od
s Ms , XlLigustrum nepalense (Wall.) . : Soo
RM . » XSyringa Bretschneideri (Hort.) 4 1 SOG
* . » &Syringa persica (L.) ‘ : é s8F
s :; » XSyringa pubescens (Turez.) . : . 38
s es » &XSyringa vulgaris (L.) . : : Sion
A insulare (Dene.) x Syringa dubia (Pers.) s . 40
= ovalifolium (Hassk.) x Ligustrina japonica (orci Neti Ac
= - 2 x Syringa dubia (Pers.) . : . 42
; 3 ‘, x Syringa Josikea (Jacq.) . 43
a . ¥ x Syringa vulgaris (L.) . : . 44
is sinense (Lour.) x Ligustrina amurensis (Rupr.) . . 45
$3 = », XlLigustrina japonica (Maxim.) . ny 46
a a , Ligustrina pekinensis (Regel) . Brey. yi
5 * » x Ligustrum Ibota (Sieb.) . ‘ ee
B, fe , Xlhigustrum ovalifolium (Hassk.) . 28
. i ,, XSyringa Bretschneideri (Hort.) . sap
a = » XSyringa Emodi (Wall.) . ¢ el
x Syringa vulgaris (L.) . ‘ 3 = ae
lipteons Manel (A. Gray) x Lonicera sempervirens (Ait.) . . 65
», | Sempervirens (Ait.) x Lonicera translucens (Carr.) . a
,, lberica (Bieb.) x Lonicera flava (Sims). . : ‘ . 66
-} - », x Lonicera sempervirens (Ait.) . : .. (OT
53 ,, x Lonicera Caprifolium (L.) ; ; «68
Sa inyolnceate (Banks) x Lonicera Caprifolium (L.) : = 69
,, translucens (Carr.) x Lonicera Caprifolium (L.) L Bora ft
‘, a », XLonicera flava (Sims) ; ‘ 25 98
_ 7 ,, &Lonicera glauca (Hill) : , ea,
,, x Lonicera sempervirens (Ait.) . 4 70
Nicotiana aria (och ) x Nicotiana Tabacum (L.)*** . . 90
A Tabacum (L.) x Datura meteloides (D.C.)*** . 7 io
i “ x Nicotiana affinis (Hort.)*** . : = 488}
93 x Petunia nyctaginiflora (Juss.)*** - 92
Psonia albiflora (Pall.) x Peonia lutea (Franch.)** . ; . 81
», lutea (Franch.) x Peonia albiflora (Pall.)** ; : . 82
Potentilla fruticosa (Lour.) x Potentilla atrosanguinea (Don) . 88
Rhodotypos kerrioides (Sieb. & Zucc.) x Kerria japonica (D.C.) . ag
Sarothamnus scoparius (Koch) x Cytisus Laburnum (L.) ; «410
= x Cytisus purpureus (Scop.) . - $d
pee Bretsaenetdent (Hort.) x Ligustrina pekinensis (Regel.)** 6
a 3 » &Syringa Josikea (Jacq.)* . svadiae
, ” », XSyringa persica (L.)* . ; Rela |
292. JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
No.
Syringa Bretschneideri (Hort.) x Syringa pubescens.(Turez.) . + 6
a A », XSyringa vulgaris (L.)* . : . &&
5 3 » &XSyringa vulgaris (L.), var. flore
pleno (Hort.)*** 5 : +, 858
,, BDretschneideri x Josikea (hyb.) x Ligustrina pekinensis
(Regel.)** . ae 8.7,
» Bretschneideri x Fasigen Gam ye canes eee Gace Wine
= “¢ ss » XSyringa vulgaris (L.)* 5) 8a
x Syringa vulgaris (L.), var. fl.
pleno (Hort.)* : «ae
Bretschneideri x persica (hyb.) x Syringa persica (L.)** . 10
Bretschneideri x vulgaris (hyb.) x Syringa vulgaris (L.)** . lla
x Syringa vulgaris (L.), flore
39 bb] 9 a7,
9) 9 39 ””
pleno (Hort.)** . = . ate
+ s ‘s 53 x Syringa pubescens
(Rurez.) = , walla
», dubia (Pers.) x Syringa pubescens (Turez.) , ; neh
» Emodi (Wall.) x Ligustrina pekinensis (Regel)** : -), da
» Josikea (Jacq.) x Syringa Bretschneideri (Hort.)* . et
»» persica (L.) x Ligustrina pekinensis (Regel)*** . : > ike
35 x Syringa pubescens (Turez.) . ; ; ee
$5 7 x Syringa vulgaris (L.) var.* °. ; : oat
» pubescens (Turcz.) x Syringa oblata (Lindl) . : Ald
Hs id “ x Syringa persica (L.) . . : a9
5 3 x Syringa vulgaris (L.) . ; ; . “208
3 arlamte (L.) x Syringa Bretschneideri (Hort.)* ; - 22
* 5 x Syringa persica (L.)* . a ‘ c 62.28
a x Syringa pubescens (Turez.)** . : eet
Waele eae Delavayi (Franch.) x Thalictrum medium (Jacq.) . see
; medium (Jacq.) x Thalictrum Delavayi (Franch.)* - 95
Tulipa Gesneriana (L.) x Tulipa Greigii (Regel)*** : ‘ . 286
5, Greigii (Regel) x Tulipa Gesneriana (L.)*** : me
», Greigii (Regel) x Tulipa sylvestris (L.)*** . : ; . 100
,, suaveolens (Roth.) x Tulipa Greigii (Regel) A ; . 98
» sylvestris (L.) x Tulipa Greigii (Regel)*** . ; ‘ . 99
Vitis Coignetie# (Pull. & Planch.) x Vitis amurensis (Rupr.)* . : ie
SYRINGA.
The genus Syringa contains but a small number of species, but two
of these species (Syringa vulgaris and S. persica) are—the first espe-
cially—very rich in varieties of the greatest beauty. On the other hand,
the remaining species have as yet afforded very few varieties, and these
generally not very marked ones. Thus, I think, there remains much to
be done in this direction.
The beautiful Bretschneider Lilac, the natural seeds of which had
hitherto yielded only flowers uniformly pink—a pink more or less pale or
more or less flesh colour—appeared to me particularly susceptible of
improvement as regards colour, form, and size of the inflorescence. The
CROSSINGS MADE AT NATURAL HISTORY MUSEUM, PARIS. 223
Muséum had introduced it from China into France in 1880, and it first
flowered in 1886. It was natural, therefore, that this establishment
should occupy itself first with this species. It will be seen that our
attempts in this direction were not without result.
The same with Syringa pubescens, introduced by us at the same time
and from the same source (first flowering in 1885). Here our efforts,
without being absolutely without result, have not had so much success.
The Ligustrina, all uniformly white, would certainly gain in interest
if we could succeed in giving them other colours; but the numerous
attempts which we have made to this end have so far completely failed.
This, however, will not prevent us from persevering.
The origin of the Varin Lilac and other Lilacs of the same group
(Syringa dubia) has remained for a long time uncertain. Some
botanists considered the Varin Lilac to be a species introduced from
China, others that it was a hybrid between Syringa vulgaris and
S. persica. A careful examination of the shrub caused me to adopt this
latter opinion. It appeared to me interesting to reconstitute this Lilac
by crossing the Persian Lilac with the common Lilac. There resulted
three plants which presented absolutely the characters of Syringa dubia.
Unfortunately these plants died before flowering. But at the same
time whilst I was working, and without any concerted co-operation, M.
Lemoine, of Nancy, pursued the same course in order to obtain a double-
flowered Varin Lilac. More fortunate than I was, he succeeded in
flowering his seedling in 1887. The hybrid origin of the Varin Lilac
was thus confirmed (see page 299).
If Lilacs have been obtained in a certain way, hitherto by crossing
Syringa persica with Syringa vulgaris, it does not appear that anyone
has ever attempted to obtain an inverse cross. This I have now done,
and I possess to-day a series of young plants thus obtained. They are
vigorous, and afford us good hope.
1. Syringa Bretschneideri (Hort.); syn. S. Emodi rosea (Max.
Cornu), S. villosa (Sarg. not Vahl.). Crossed with Syringa
Josikea (Jacq.).
Object.—To obtain deeper colours.
This crossing I began on May 20, 1890, and lave repeated for several
years upon a certain number of inflorescences with variable results.
Fertilisations of 1890—231 plants obtained.
The flowering commenced with two plants in 1896, and since then
some fifty have flowered.
Fertilisations of 1894—35 plants, which began to flower in 1899.
Characters of the Lilacs produced by this cross :
Habit closely resembles that of S. Bretschneideri.
Leaves smaller and less firm than on this latter, larger than on S.
Josikea, bearing hairs upon the under side, as in S. Bretschneideri (in
S. Josikea the leaves are glabrous).
Inflorescence in form the same as in S. Bretschneideri: that is to say,
much longer and more branched than in S. Josikea, and moreover fuller
and better furnished, pyramidal and in open panicles, rachis and petiole
tinted violet and plum colour as in S. Josikea.
29.4 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Flowers much resemble those of S. Josikea:
1. In colour, being violet, violet-tinted, bluish. or reddish, instead of
being pink or pinkish-white, as in the Bretschneider Lilac.
2. By their slenderer dimensions than in the Bretschneider Lilac.
B Cr
Fic. 104.—A—Syrinea Jostxma (Jacg.) 2. C—Syrinca Brerscnermert (Hort.)
=§. Emopr rosea, Max. Cornu 2. B-—Syringa Brerscuneipert x §. Josrkma.
3. By their form being that of a trumpet instead of a funnel; never-
theless the divisions are larger, more rounded, less incurved than in
S. Josikea, and they finish by turning outward like the Bretschneider
Lilac. (Fig. 104.)
CROSSINGS MADE AT NATURAL HISTORY MUSEUM, PARIS. 225
The object sought for (change of colour of the flower) has therefore
been obtained in as satisfactory a manner as possible, whilst preserving
the habit of growth of the Bretschneider Lilac.
2. Syringa Josikzwa (Jacq.) xS. Bretschneideri (Hori.).
From crosses made in 1890 I have obtained thirty-two plants, which
have commenced to flower in 1897.
The result has turned out fairly the same as in the inverse cross (see
above). In comparing, however, the two results it may be noted that
in this cross :—The leaves are longer, with more attenuated points, and
less hairy, sometimes altogether glabrous. The inflorescences are
narrower and a little less furnished; the rachis is of darker colour. The
buds are redder, and the divisions of the flowers wider open and more
recurved. The flowers also present more red, and some of the plants
have them of a very striking purplish colour.
To sum up, in the two cases, the influence of the parents may be
thus specified :—S. Bretschneiderit shows itself particularly in the habit
of growth, the stems, the leaves, and the shape of the inflorescence.
The influence of S. Josikea is seen most in the shape of flower, its
colour, form, and dimensions.
3. Syringa Bretschneideri (Hort.) x Syringa vulgaris (L.).
Object.—To obtain new colours in‘the Bretschneider Lilac, an agree-
able scent, and an earlier flowering. (The Bretschneider Lilac is pink,
has a smell resembling that of Privet, and flowers twelve days later
than the Common Lilac.) Numerous and repeated attempts were made,
at first taking pollen from single-flowered varieties, and then from double-
flowered ones.
(a) Crosses with single-flowered varieties.
1890. Eleven inflorescences treated. Five gave seed, none
germinated.
1893. Five inflorescences treated. ‘Two yielded seed, which gave
one plant.
1894. Four inflorescences treated. Two yielded seed, which gave
ten plants. One of these plants flowered in 1899 a lovely pink. (The
variety which furnished the pollen used to obtain this plant is
the Lilac ‘ Charles X.’)
1895. Three inflorescences treated. One yielded seed, which gave
two plants.
1896. Five inflorescences treated. One seed gathered, gave one
plant.
1897. Three inflorescences treated. Two yielded seed, which gave
fourteen plants.
1899. One inflorescence treated. Two fruits appeared to be good
on July 4, 1899.
(b) Crosses with double-flowered varieties.
1894." One inflorescence treated. Four seeds obtained, not
germinated,
22.6 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
1896. Two inflorescences treated. One gave seed, which did not
germinate. :
1897. One inflorescence treated. Gave seed, which did not germinate.
1898. One inflorescence treated. No result.
4. Syringa Bretschneideri (Hort.) xS. persica (L.).
Object.—The same as with S. vulgaris.
1895. One inflorescence crossed. One seed gathered, which gave a
plant, which in 1899 has flowered in a very peculiar manner. Colour
pink. Inflorescence arranged in fives at the extremities of the stalks.
Flowers rather slender.
5. Syringa Bretschneideri (Hort.) xS. pubescens (Turcz.).
Object.—To obtain earlier flowers, and an agreeable scent.
1898. One inflorescence treated. Result nil.
6. Syringa Bretschneideri (Hort.) x Ligustrina pekinensis (Regel).
1895. Six inflorescences treated. Some seeds obtained, but they
have not germinated.
7. Syringa Bretschneideri x Josikea (hybrid) x Ligustrina peki~
nensis (Regel).
Cross of second degree.
1899. Two inflorescences treated. Seventy-two fruits swollen, and
so far promising to perfect.
8. Syringa Bretschneideri x Josikea (hybrid) x 8S. Josikea
(Jacq.).
Cross of second degree.
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BREEDING STAPLE FOOD PLANTS. 261
produced to secure one superior one. A prominent Potato breeder has
said that not more than one new variety in two thousand proved
sufficiently valuable to become a commercial variety; yet the breeding
of Potatos has added sufficient to the value of that crop to pay for the
required labour a thousand, if not a million, times over.
The above-mentioned experiments in Wheat breeding are reported
upon in full in Bulletin No. 62 of the Minnesota Experiment Station,
and a number of copies are held in reserve for exchange for writings on
plant and animal breeding.
STEPs IN VARIETAL KH VOLUTION.
Many amateur hybridisers make a mistake in thinking that the
hybrid is the end sought, the difficult feat to be performed, the result
which brings value and creditable mention. Only when that number
of hybrids is produced that a really useful or attractive form is secured
and given to the world are the results valuable from an economic or
artistic standpoint ; and only when the method is so recorded as to be a
suide for future work are the results valuable from a scientific stand-
point. In the case of many crosses, the individual plants, of hybrids between
dissimilar species, mostly revert downward in yield, or in other intrinsic
qualities. It is only the exceptional plant which varies strongly in the de-
sired directions. Extensive selection must therefore accompany crossing
to get the highest possible results. The selection should begin with the
varieties to be crossed. How little we know as to the average results of
the crosses between any two species or varieties, and how little are we
able to predict how many individual plants of each cross we must throw
away for each useful one we shall find under rigid selection! There
would seem to be no end to this portion of botanical research.
Selection of the parent plant within the variety is ofttimes very
important. In Wheat, for example, there is great variation in the
strength and in the prepotency of the individual plant, and it is im-
portant that good plants be chosen and that the power of these be tried
to see that they are potent in the production of good plants; in other
words we must raise a generation of plants from each parent plant, and
compare these second generations or broods that we may know the
relative values of each of the mother or father plants as parental stocks.
We must measure the breeding value of the parent plants by judging or
comparing their produce. The breeder of pigs likes to have the male,
which is to head his herd, show his pedigree on his back ; he also requires
a good written pedigree, but the value of the sire or dam is still better
judged by seeing a large number of his or her progeny.
Since the labour of developing hybrids, when fully carried out, often is
very great, the probabilities of useful results from crosses should, where
practicable, be increased by carefully selecting the foundation or parental
individuals. Since variation may occur all along the line, where it is
practicable, the best flower should be chosen on the best part of the best
plant.
Hybridising, in breaking up the centripetal force of heredity and by
letting loose the centrifugal forces of past generations—which forces, acting
262 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
alone or in combination, express themselves as old or newly compounded
forms or qualities—often gives the best materials for the plant breeder to
work upon. Whether the cross is radical or mild, the centrifugal force
seems to reach its climax in a few generations ; but the tendency to vary
ofttimes continues for many generations, differing with the individual
plant in close fertilised species, and with pairs of plants mated in open or
insect fertilised species, or in case of artificial fertilisation.
The practical point is that it is often wise to give free rein to varia-
tion for at least a few generations. Not all the resulting plants need be
kept, but it is wise to keep very many strong ones or those having special
characteristics. Largeness of numbers in the progeny requires system
in the selection, that the intrinsic qualities may be sought after in the
most effective manner, and that the labour be not wasted upon many
useless forms. The intrinsic or special qualities should first be sought,
and then the stocks should be bred to uniformity of type afterwards.
Much stress has been laid upon having the forms uniform in all their
characters—-in matters of appearance, if you please—as well as in matters
pertaining to special values. No doubt the longer time required to fix
several characters makes the variety more stable ; but if the greater labour
be nearly all directed for the longer time to the intrinsic or special
qualities sought, no doubt time and labour would be expended to more
purpose. ' For practical purposes many new hybrids produced from seeds
are fixed in type by rigid selection for only three to six generations; and
the stronger growth or fruiting character of most food-producing plants
may be fixed in a comparatively short time, whether open or close
fertilised, while in the case of plants propagated by division they are at once
sufficiently well fixed in character for practical uses. In such cases as
the open-fertilised Sugar-Beets, where the seeds are raised in one place
and sold in many lands, the longer time spent in fixing characters, the
attention to fixing the permanency of form of leaf and other non-intrinsic
qualities, doubtless has much weight; but in the case of grains, forage
crops, &e., bred in the general locality in which they are to be used, the
stability of the characteristics of large yield, good quality, and hardiness
is usually provided for by rigid selection during only a short term of
years. The American farmer has wisely sought the large sound ears of
corn, caring little whether the cobs were all of one colour or the leaves of
similar form.
Since selection affects crops to which, in the aggregate, are attached
immense value, the selection should be from among such large numbers
that the greatest increase in yields and qualities will surely result. M.
Vilmorin and other breeders of Sugar-Beets have fully recognised this
most important principle. Here, quality of sugar per acre, together with
its availability, are the requisites, and these experimenters early took a
direct road for results. They dealt first with varieties, securing the best ;
then they sought the best roots; and then they tested the capabilities of
each mother root in the ability of its seeds to produce roots with high
yield of sugar and high purity of juice—in otber words, its prepotency.
With the best roots from the best mother plants, the process was repeated
indefinitely, each season seeing a gain of one-fourth to one-half per cent.
of sugar, and little, if any, lessening of the gross yield per acre of the crop
BREEDING STAPLE FOOD PLANTS. 263
of Beets. The past and future value of this work to the world is
represented by vast sums of money.
Increasing superior stocks, giving them trials beside standard sorts,
choosing out only those which are superior, and then increasing them
for the public, is not only an expensive operation, but one requiring much
care. In this many of our breeders of new things have failed, because, as
among inyentors, business ability has not in all cases been coupled with
the ability to produce new things. The public has so little confidence in
new things, because they have been asked to pay long prices for the
privilege of experimenting with so many newly originated varieties sent
out before their values were fully determined experimentally. Far more
of this experimenting should be done on the grounds of the introducers,
and on the grounds of such establishments as public experiment stations,
where trained experts are employed for the work. This is especially import-
ant with field crops. While in the case of the ornamental plants, or of fruits
and some vegetables, it is quite practicable for each grower to try a few
plants of many varieties in a very inexpensive way, it is not so with grain
and forage crops. While the crucial test for new things is always the
test given by the practical growers, yet the plat testing of new varieties,
as of Wheat, Sugar-Beets, Field Peas, or of Timothy, could easily be
made at a sufficient number of places, such as experiment farms, so that
the growers could in most cases rely on the formal plat tests of the
experimenters. These tests should always be done in such a manner as
to imitate field conditions; the soil should be uniform and the labour
should be performed in an expert manner. This is expensive work that
can properly be undertaken by the Government for the whole people.
Tue Furure or Puant BREEDING.
The literature on plant breeding is much scattered. There is no
recently published bibliography ; much that has been put into print is
wrong; and that faith which people should have in increasing the value
of crops through heredity is not strongly built up or increased on reading
much that has been printed. Charles Darwin still remains the great
collator and interpreter, but his thoughts centred most on clearing up
the larger scientific question of Evolution ; but between the lines there is
inspiration for those who add to the world’s, wealth by breeding animals
and plants. Darwin had the spirit for gainig experimental knowledge
of heredity by actually experimenting in a large way; but time has been
necessary for his followers to earnestly take this work up in detail. Prof.
Hugo de Vries and others who are looking systematically for the nature
of changes, the laws of breeding, the best means of producing important
results, are engaged in a most important work. Against the great difficulties
with which the work is beset, is the vast scientific and economic utility
of any useful discoveries which may result.
This work requires not only much time, but the expenditure of money.
A few things done well, with conditions under control, and records and
specimens properly kept, should be the motto of the experimenter.
Persons who are making new races or varieties have done far too little
in recording methods and results. They have usually found their first
264 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
start by accidentally discovering a new plant. They know only how the
chance seedling was further selected and made more useful. Those who
have produced crosses often have no carefully-made notes which, if kept,
would be a guide in future experiments. .In the Northern part of the
United States, for example, numerous new seedling Apples have been
originated. It may be that some one cross has resulted in the production
of most of these. Were it found true that a cross between the Duchess
and Roman Stem Apples had produced a number of good and hardy
varieties, and that from a like number of crosses between other varieties
nearly all had failed in hardiness or in other particulars, we could inter-
pret the results as indicating that energies would best be spent in crossing
the two varieties mentioned, and in testing their resulting seedlings.
There is a large amount of this breeding going on. The notes could be
simply and easily kept ; and with careful records the work is more pleasure-
able, and the best plants are more certain to be selected from among
the many crossbreds which must be produced to get a few superior ones.
The idea that there are secrets in variety production is not worthy of
the age in which we live, and it does not prevail in the minds of the
leading men interested in the breeding of either plants or animals. Men
have sometimes mistaken their artistic skill for secret knowledge—
‘‘ science for which no language has yet been developed.” Under investi-
gation this knowledge or art often proves to be founded upon the chance
discovery or selection of a very superior plant or animal, which the
grower has been wise enough to multiply. ‘“ The secret knowledge is
being aware that the pretending wise breeder is claiming to know some-
thing when he does not.”’
Important subjects eventually reach the school-room. The pedagogies
of plant and animal breeding is becoming a lusty infant. Through our
schools of agriculture much can be taught. Since breeding is mainly
an art, the practical work will always predominate over the scientific in
the properly developed course of study. Since experiments and practice
in animal breeding are not usually practicable in a school, both because
of the long series of years needed, .and especially on account of the
expense of even such small and rapidly reproducing animals as fowls,
most of the practice work, and most of the demonstration experiments,
must be confined to plant breeding. While the teacher needs experience,
he also needs access to the literature. This can only be reached with
great effort, since the valuable writings are much scattered. The col-
lections of agricultural books in the schools of agriculture, in the offices
of agricultural newspapers, or in general libraries, are, as a rule, in poor
condition. The articles on each subject, besides being in fragments in
various publications, are not properly catalogued. People have as yet
hardly awakened to the fact that agricultural education and experimenta-
tion are very expensive, yet, even at a high cost, are very profitable. And
the more nearly the provision of money is adequate, the better are the pro-
portionate results, whether the money is spent in educating boys to be
farmers or technical agricultural scientists, or in the conducting of original
research. The breeding of plants can properly be made a minor subject
in many secondary, higher, and post-graduate schools.
The more numerous classes of plant breeders are the gardeners and
BREEDING STAPLE FOOD PLANTS. 265
farmers, though as a rule they only select in a crude, yet sometimes very
effective manner. Next come the amateurs, who choose a special line,
and often carry it out, in a more or less effective manner, to a very suc-
cessful issue. These men have been especially numerous in England,
where amateur science has been fashionable among professional and even
among business men, and gentlemen retired from business. Third may be
placed the commercial seedsmen who, securing the stock of good varieties
from the amateur, the gardener, or the farmer, improve them from year
to year, using their carefully selected stock of one year, for growing fields
of the seeds for the market the next. The attention of professional
scientifically trained officials is being turned to the breeding of plants,
and to the study of the breeding of plants and animals. Hybridising
and plant improvement have been but little entered upon by women, yet
there is room for them here as in many other lines requiring manual
skill, patience, and interesting study. The general results to the public
of improvements in plants and animals cannot easily be counted, since
the results are accumulative, the work of one year serving as a foundation
for better results the next.
Hach locality has its peculiar needs from the plant breeder. In
Minnesota the low yield of Wheat on our rich lands calls loudly for
varieties which will add 20 or even 50 per cent. to the crops of grain.
We also need a variety of Red Clover which will stand our severest winters
as well as the common variety stands our best winters.
In Dakota a Bromus inermis is needed, which will still better resist
drought than the common variety of this species newly introduced there
on account of its drought-resisting power. In England varieties of Wheat,
Oats, and Barley are needed, which, under the heavy fertilising, will not
lodge, but will stand erect, making it practicable to use the self-binder,
and thereby save expensive labour. On the moorlands of Western
Europe are needed varieties of the common forage and grain crops, especi-
ally bred to thrive on peaty soils. Every locality has its peculiar needs,
and in the aggregate these needs represent enormous values. Plant
breeding may yet find a large place in agricultural improvement, taking
its place beside chemistry and physics. The importance and the difficulty
of the work make it worthy of the energies of the best minds.
266 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
ON THE USE OF TRANSPARENT PARCHMENT PAPER BAGS
FOR ARTIFICIAL FERTILISATION.
By Professor Huco pr Vries, Amsterdam University.
SincE the year 1893 I have used for my experiments in artificial
fertilisation in the open air caps and bags made of transparent parchment
paper, such as are used largely in commerce for fruit and Grape
culture.
When it is desired to conduct experiments in selection with artificial
pollination this must be effected in gardens, and therefore in the open
air, because prior to the selection it is not known from which individuals
the seed will have to be gathered; and after the selection it is, as a rule,
too late to transplant the seed-bearers in order to transfer them indoors
or into greenhouses. I therefore do all my fertilisation in the open.
In order, therefore, to protect the flowers concerned from insects’
visits, | cover them with bags, which, according to my experience, are
rarely damaged ; and both in sunny weather, as well as in wet and windy,
keep in excellent condition.
In wine culture, both on the Rhine and the Moselle, as well as else-
where, these bags are used for the purpose of protecting the Grapes
during their growth from wasps, vermin, and birds, fostering their growth
and improving the quality.
They are made of thin transparent parchment paper, saturated with
some fatty substance, which prevents the passage of moisture, but permits
that of light and sunshine. There is developed in these glass-like covers
a greater and more lasting warmth, which consequently helps the growth
of the fruits and Grapes, and presumably increases their sugar contents.
Shortly after the flowering, when the berries and fruit have set, the
caps and bags are placed over them, folded above around the fruit stalk,
and bound either with a metallic clip or with string. They last for
several years.
These parchment paper bags are made in the bag factory of Mr. P. J.
Schmitz, in Diisseldorf, of any required size. For fertilisation of
Papaver somniferum 1 use, for instance, bags measuring 15 x 20 centi-
metres. or covering the flower stems of Ginothera Lamarckiana I
need bags 20 x 40 cm., or even larger.
They are also made with perforations which afford more air, and on
account of the smallness of the holes might also be used in fertilising
work, though I have made no experiments with them so far.
My experience with these bags is fairly extensive. With Papaver
somniferum I have for five years used such covers for some fifty to 100
flowers each year, fertilising partly with own pollen and partly with
foreign pollen. With Q/nothera Lamarckiana and related species and
varieties | have used annually some hundreds—in 1898, indeed, about 600
individuals were covered. Furthermore, with the aid of such bags I have
artificially fertilised Antirrhinum majus, Chelidonium majus, Linaria
USE OF TRANSPARENT PARCHMENT PAPER BAGS. 267
vulgaris, Lychnis vespertina and L. diurna, Papaver mudicaule and
P. Rheas, Silene Armeria and S. noctiflora, and several other species and
genera.
In many cases it is certainly more convenient to carry out the fertilisa-
tions in cages. Formerly I used small removable cages of wire gauze
or tiffany, and now I have in my experimental garden a still larger
cage made of fine wire gauze. But insects now and again can find their
way in, either as eggs or larvee, existing on the trial plants or in the soil
in the pots. I use, therefore, cages only in such cases when chance insect
visits would not be detrimental to the results of the experiments. For
fine work, however, I use exclusively these paper bags.
In wet weather the parchment becomes damp and limp; it does not,
however, tear. No water penetrates, and frequently after the rain it is
found that considerable quantities of water have accumulated in the folds
of the bags. Even in windy, stormy weather they are not torn unless
sharp-pointed stakes are used with the plants, upon which the bags
become impaled. Even in that case, however, the hole, which may
result in weather at once windy and wet, and through which the stick
protrudes, is practically stopped thereby, and hence even in this unfavour-
able case no insect would, as a rule, find entry.
The bags have furthermore the advantage that the particulars of the
experiments concerned can be written upon them either with the so-
called Indian nib or with pencil.
Solitary flowers, which only need fertilising once, such as Poppies,
form evidently the most convenient cases to handle. With Antirrhinwm
and (Hnothera, I envelop the whole flowering stem in a bag and open
this every two or three days in order to fertilise the fresh flowers or to
castrate the new buds. Hach plant requires then usually two or three
weeks before a sufficient quantity of seed is fertilised. But the frequent
opening and closing of the bags does not damage them.
To actual risks the flowers in these bags are only exceptionally
exposed. For green leaves too little light penetrates, and thus they fade
and become yellow; but only if the experiments be of long duration.
Fraught with greater danger is the heat on hot August days. In the full
blaze of the sun, the air in the bag can become so warm that the young
half-grown flower buds drop off, and are thus lost for the continuance
of the experiment. This often happens with Cnothera Lamarckiana.
Or the flower buds concerned may die from drought, as occurs with
Antirrhinum majus. Further, it appears that great heat is detri-
mental to the formation of the pollen, as I found under such circum-
stances that for several days in succession the young flowers of certain
varieties of Gnothera Lamarckiana were without any pollen or had very
little.
It is possible that in such cases the perforated bags would suit better ;
in rainy weather, however, they would plainly be less secure.
I close my bags usually, not with metal clips, but with coarse string ;
it is, however, not merely a question of excluding bees, humblebees, and
flies, but also to guard against the entry of earwigs, which find shelter
in their folds, and by devouring the pollen can often prove very detri-
mental in cases of artificial self-pollination.
268 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
The bags when once used can be used again repeatedly, so far, at
least, as the possibility of adherent pollen to the immer side carries no risk
with it. I utilise the bags also for collecting such kinds of seed as might
easily be blown away. Tothis end the flower stems concerned are simply
enveloped in the bags before the seed is ripe. Later on the entire bunch or
stem is cut away with the bag upon it. In this way, for instance, I have
almost always harvested the seed of my fasciated races of Composite,
Taraxacum officinale, Aster Tripoiium, Crepis biennis, and Picris Ier-
acioides. The gathering takes thus but little time, and there is practically
no loss to speak of.
In view of the experiences above described, I recommend all who
have to carry out crossing or self-pollination experiments in the open to
cover the flowers of their trial plants with bags of parchment paper.*
* Thanks to the kind co-operation of the manufacturer, Mr. P. J. Schmitz, in
Diisseldorf, specimens of these parchment paper bags of all sizes were exhibited
at Chiswick, and placed at the disposal of the visitors.
HYBRID CINERARIAS. 269
HYBRID CINERARIAS.
By R. Irwin Lyncu, F.R.H.S., Botanic Gardens, Cambridge. -
In this paper I give, as requested, an account of my own hybrids, adding,
however, some remarks upon hybrids by Mr. W. J. James, as desired by
him. All the crossing I have done was suggested by an interesting
and stirring discussion in Nature some four years ago, between Sir
William Dyer and Mr. William Bateson, upon the origin of the florists’
Cineraria ; butit should be observed that many of the crosses were made
without any expected bearing upon that question. As might be expected,
the time at my disposal for the particular work has been altogether
insufficient for the record of any considerable detail, and I regret there-
fore that all the scientific results that were possible cannot be forth-
coming. I use the word ‘“ hybrid” in speaking of plants and “cross”
with reference to cross-pollination.
The wild plants I have worked with are :
Senecio cruentus, Hort. Kew., non D.C.
Heritieri, D.C. (Cineraria lanata, L’Hérit.)
multiflorus, D.C.
Tussilaginis, Less.
and with these in several instances, the florists’ Cineraria has been com-
bined.
It is important to note that the above cruentus, familiarly known
as “ Kew cruentus,”’ can only be called cruentus by taking the too broad
view to which botanists are sometimes liable. There are several im-
portant differences, inasmuch that I find it a very invariable plant, only
kept through the winter with great difficulty, comparatively colourless in
its nature, and so poor in attractive qualities that my judgment revolts
against the idea that any florist ever took it in hand to improve it. No
florists’ flower ever originated from a plant which had not already much
to recommend it. With this plant, however, work has been done, and
also much written, perhaps, upon the assumption, to which I entirely
demur, that it is at all a crwentus in this connection. It is quite an
unfair assumption, I believe, to both sides of the question, as to the origin
of the florists’ Cineraria, and I may perhaps be allowed to make a friendly
protest against the disregard of the botanist for differences which are
great to the horticulturist. Very valuable is the work of the botanist
with books and dried plants, but I deplore the practice of merging under
one name and without distinction plants which are absolutely different
and distinct, and actually known not to be identical. If attention is
drawn to these differences they are admitted to be quite evident, but
they are said not to be important. Now here lies, I {am sure, a most
gigantic error. No botanist who does not work in the garden with
living plants can appraise the degree of importance which attaches to a
difference he can recognise, and while I quite appreciate and‘fully under-.
stand the arguments and difficulties of the other side, I do venture to
270 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
suggest that some remark should be made, or sign given, in all botanical
writings, without exception, when plants are put together without being
considered identical. All the plants above enumerated, understanding of
course a good cruentus, I believe to be in the florists’ Cineraria, with the
exception, however, of Senecio multiflorus, and this I am sure is clearly
notin it. To the Cineraria, however, I shall return, and shall, I feel
sure, justify my contention.
Some general observations, based upon these crosses, may be made
from a botanical point of view, and the chief, perhaps, is that while
any two species cross with facility, not one can set seed with pollen from
the same individual plant. >», Hotel Métropole, 40
Dioscorea, 278
Diplacus, 337
Dipsacus, twisted, 70
Disa, 15
Discontinuity, examples of, 64
Disemma, 337
Drosera, 33, 241
Entry card, 5
Epidendrum, 15
Epi-Lelia radico-purpurata, 102
Epilobiums, 181
as radicans, 102
Epiphronitis Veitchii, 16
Erica, 197
Erigeron Hubsenii, 202
Erodium, 216
Eucalyptus, 250
Failures, 76
False hybrids, 82
Fern hybrids, 288, 298
Fertility in hybrids, 117
Foxglove, 185
Fuchsia, 337, 341
Generic hybrids, 77
Geum, 186
Globe flowers, 286
Gloxinia, 333
Gooseberry, 168
Graft hybrids, 38, 237
Grapes, 210
Guests specially invited, 6
Hardiness affected by hybridisation, 128
Hedychium, 215
Heuchera, 36
| Hieracium, 187
Hollyhock, 33
Hybrid, false, 82
i fertility in, 117, 200
* first recorded, 56
» generic, 77
5 graft, 237
» Stability of, 121
vigour of, 124
Hybr idisation and botany, 181
a in the United States, 128,
209
+ limits of, 125
; of Cotton, 140
~ of Pineapples, 138
partial, 86
Hybridising, Anthurium, 67
early notes of, 56
Hybrids, at Nat. Hist. Mus., Paris, 220
», supposed, 219
Hymenocallis, 33
348 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY.
Influence of either parent, 251, 256 Potentilla, 234
Inheritance of generic characters, 102 Prepotency, excessive, 82
- 5, Specific characters, 97 Primrose, 188
- ,, varietal characters, 90 Primula, 286
Tris, 235 Pteris, 22
Pyrus, 211
Kalanchoe flammea, 9
Kalo-Rochea, 33 | Quercus, 338
Lelia, 16 Raspberry, 37
Lelio-Cattleya, 16, 346 ‘ x Strawberry, 58
5 leucoglossa, 103 Rhododendron, 22
Lastrea, 20, 289 4 Eos, 119
Ligeria, 333 intermedium, 200
Ligustrina, 229 Ar Numa, 118
Ligustrum, 230 Rhodotypos, 232
Lilac, 218, 222, 299 Ribes, 168
Lilium, 33, 36
Limits of crossing, 125
Lomaria, 21
Lonicera, 233 Saffron, 275
Luncheon at Chiswick, 39 Salix, 186
KA ,, Waddon House, 5: Salvia, 201
Lychnis, 64, 70, 197 Saracenia, 26, 188
Sarothamnus, 233
Maize, 143 Schedule, 2
Masdevallia, 18 Scolopendrium, 22, 296
Medlar, the Bronvaux, 237 45 Ceterach hybrid, 195
Mimulus, 280 Self-sterility, 214
Mirabilis, 279 | Senecio, 29, 269
Monstrosity transferred, 69 | Sobralia, 19
Spathoglossis, 19
Species, the problem of, 59
5 definition of, 76, 199
Stability of hybrids, 121
Roses, 30, 337
Rubus, 37, 187
Go
Narcissus, 183
Natural hybrids, 181, 200
Nepenthes, 26
‘ Dicksoniana, 25 Sterility and affinity, 80
3, Morganiz, 27 :; 214
Nicotiana, 235 Strawberry, 37
Nuphar, 201 Structure of hybrids, 146
Nymphea, 31 Sugar-beet, 257
Syringa, 218, 222, 229
Oak, 338 |
Odontoglossum, 19, 190 | Tacsonia, 35, 343
a cirrhosum, 194 | Thalictrum, 236
= Denisonix, 190 | Thunia, 19
5; elegans, 193 Tillandsia, 26, 330
- Hallii, 194 | Tragopogon, 185
Orange hybrids, 128 | Trientalis, 215
Orchis, 36 Trollius, 286
Order of proceedings, 3 | Tulipa, 236
Oxlip, 188
| United States, hybridisation in, 128, 209,
Ponia, 234 257
Pansy, 282 Urceolina Clibrani, 314
Paper bags for protection, 266 :
Parental influence, 251, 256 | Vanda, 20
Paris, Nat. Hist. Museum, work at, 218 | Variation of primary hybrids 106
Partial hybridisation, 86 ; » secondary ,, 1il
Passiflora, 35, 146 Varietal evolution, 261
s structure of hybrids, 146 Varin Lilac, 299
Pelargonium, 35, 281 Verbascum, 36, 185
Phalenopsis, 19, 193 Vigour of hybrids, 124
a intermedia, 189 Violas, 282
Pineapples, 138 Vitis, 210, 233
Plant breeding, 263 Vriesia, 27, 253, 326
Plants exibited, 11
Polemonium, 36 | Wheat, 195, 259
Pollen, capability of, 82 Willow, 186
Polyanthus, 287
Polypodium, 21, 291 Yam, 278
Polystichum, 21, 293
Poppies, hybrid, 203 Zygocolax Veitchii, 213
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