July  13,  1899. 
■JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
25 
The  Chairman’s  Opening  Speech. 
After  expressing  the  pleasure  given  by  the  presence  among  them 
that  day.  of  friends  from  across  the  sea,  Dr.  Masters  said  that  he 
thought  it  was  their  bounden  duty  to  thank  the  Council  of  the  Royal 
Horticultural  Society  for  affording  the  opportunity  of  discussing  one  of 
the  .most  important  subjects  in  modern  progressive,  experimental 
horticulture.  He  laid  stress  upon  the  word  “  experimental,”  because 
he  believed  that  the  future  of  horticulture  depended  very  largely  upon 
well  directed  experiment.  As  far  as  practical  cultivation  went  we 
were  not  very  much  in  advance  of  our  forefathers,  but  we  had  better 
tools  to  work  with,  and  therefore  were  able  to  produce  better  results. 
I  or  many  years  past  new  plants  had  been  eagerly  sought  after,  but 
nowadays  new  plants,  with  the  exception  of  Orchids,  were  compara¬ 
tively  few,  for  by  far  the  greater  part  of  the  earth’s  floral  treasures 
had  been  discovered  and  turned  to  accoimt.  The  new  plants  of  the 
present  day  were,  as  a  rule,  called  into  being  by  the  hybridist  and 
the  cross-breeder.  Dr.  Masters  then  briefly  reviewed  the  rise  and 
progress  of  hybridisation  as  a  recognised  art,  from  the  days  when  the 
sexuality  of  plants  was  first  discussed.  The  work  of  Camerarius, 
Millington,  Grew,  and  Morland  was  touched  upon. 
In  Ii60  Ivolreuter  began  a  series  of  elaborate  experiments,  but 
as  these  were  made  with  no  practical  aim  they  were  fruitless.  Years 
after  the  then  President  of  the  R.H.S.,  Mr.  Thomas  Andrew  Knight, 
and  Dean  Herbert  took  up  the  work.  The  labours  of  Gsertner, 
Xaudin,  Naegeli,  Millardet,  Lord  Penzance,  and  Engelheart  formed  a 
fitting  succession  to  those  of  the  earlier  enthusiasts.  Darwin’s 
researches  and  experiments  in  cross-fertilisation  came  as  a  revelation 
to  many  practical  experimenters,  and  since  Darwin’s  day  much  had 
been  accomplished.  Allusion  was  made  to  the  curious  and  mistaken 
prejudice  that  has  existed  in  the  past  against  the  extension  of  hybridi¬ 
sation  on  the  part  of  some  botanists.  It  was  not  wonderful,  perhaps, 
that  these  gentlemen  should  have  objected  to  the  inconvenience  and 
confusion  into  which  their  systems  of  classification  were  thrown  by 
the  introduction  of  hybrids  and  mongrels.  This  misconception  had 
now  been  removed,  and  it  was  generally  acknowledged  that  it  lay  in 
the  power  of  the  hybridiser  and  cross-breeder  to  furnish  us  with  much 
information  as  to  the  affinities  of  the  plants  they  dealt  with — informa¬ 
tion  that  would  greatly  assist  botanical  science  in  coming  to  some 
conclusion  as  to  the  exact  status  of  a  species,  and  the  relation  of  one 
species  to  another. 
Hybridisation  and  Cross-breeding  as  a  Method  op 
Scientific  Investigation. 
This  phase  of  the  subject  was  dealt  with  appropriately  enough  in 
the  first  lecture  by  Mr.  Bateson,  M.A.,  F.R.S.,  of  Cambridge.  Mr. 
Bateson  proceeded  without  ceremony  to  disclaim  the  possession  of  any 
botanical  knowledge  whatever  on  his  own  part.  He  had  never  raised 
a  plant  hybrid  himself,  but  as  a  zoologist  he  had  been  impressed  with 
the  vastness  of  the  field  which  hybridisation  offered  for  research. 
Although  the  field  was  so  vast,  however,  the  methods  of  research  were 
simple  ;  there  was  plenty  of  material  ready  to  hand,  and  it  was  com¬ 
paratively  easy  to  do  something.  On  the  other  hand,  if  this  “some¬ 
thing'’  was  to  be  of  value,  great  patience  and  labour,  as  well  as  careful 
elaboration  of  plans  were  necessary.  With  regard  to  the  aims  that 
actuated  the  cross-breeder,  the  first  was  to  bring  light  to  bear  on  the 
problem  of  species.  Xo  one  could  yet  define  what  a  species  was,  and 
yet  the  phenomenon  of  species  was  a  very  real  one.  Some  groups  of 
plants  were  not  sharply  defined  the  one  from  the  other,  but  there  were 
hundreds  that  were.  It  was  for  the  cross-breeder  to  determine,  not 
only  what  species  were,  but  also  how  they  originated.  The  generally 
accepted  view  was  that  they  originated  by  the  accumulation  of  small 
differences,  by  the  segregation  of  offspring  of  the  same  parents,  and  by 
the  survival  of  those  that  were  fittest  to  bear  the  struggle  of  life.  It 
was  easy,  continued  Mr.  Bateson,  in  his  forcible  way,  to  state  this  in  a 
general  way  as  a  general  thesis,  but  to  apply  the  statement  to  a  single 
case  was  a  harder  matter — in  other  words,  the  general  proposition  was 
clear,  but  the  specific  proposition  was  beset  with  difficulties.  Then, 
again,  there  was  the  problem  of  how  far  cross-breeding  had  the  effect 
of  “  swamping  out”  the  small  initial  variations  in  the  plants  operated 
upon.  Revolution  rather  than  evolution  had  taken  place  of  late  years 
in  the  ranks  of  such  races  as  the  Xarcissi  and  the  Begonias,  and 
varieties  were  continually  coming  into  existence  whose  differences  were 
specific.  Discontinuity  of  variation  was  a  common  phenomenon,  and 
although  variations  might  not  make  themselves  apparent  in  the  first 
generation  they  usually  did  in  the  second  or  the  third. 
Hybrid  Anthuriums. 
A  little  surprise  was  in  store  when  Monsieur  de  la  Devansaye  was 
called  upon  to  read  a  paper  on  Hybrid  Anthuriums,  as  his  name  did 
not  appear  upon  the  schedule.  M.  de  la  Devansaye  very  briefly  gave 
his  experiences  in  dealing  with  this  genus  of  beautiful  plants  which 
he  has  done  so  much  to  improve.  The  two  rules  commonly  accepted 
in  cross-breeding  were  (l)  that  in  most  species  results  could  only  be 
obtained  when  pollen  of  the  same  species  was  taken  from  a  different 
plant  to  that  of  the  seed-bearing  parent  ;  (2)  that  Spathiphyllum  crossed 
with  pollen  of  Anthurium  yields  a  progeny  variegated  in  flowers  and 
foliage.  Plants  with  variegated  flowers  were  more  vigorous  than  the 
parents,  but  the  reverse  was  the  case  with  plants  having  variegated 
leaves.  To  the  two  rules  mentioned  M.  de  la  Devansaye  added  a  third, 
that  as  after  many  years’  experience  he  had  found  that  the  second  and 
third  generations  exhibited  variations  not  apparent  in  the  first,  it  was 
an  error  to  destroy  apparently  unaffected  progeny  of  the  first  genera¬ 
tion  ;  very  seldom  was  any  variation  produced  immediately,  whilst 
in  the  second  generation  50  per  cent,  would  give  a  change,  in  the  third 
generation  75  per  cent.,  and  in  the  fourth  80  to  85  per  cent. 
>  Hybridsation  as  a  Means  of  Pangenetic  Infection. 
The  task  of  dealing  with  this  somewhat  cryptic  branch  of  the 
subject  was  consigned  to  the  capable  hands  of  Professor  Hugo  deVries 
of  Amsterdam.  In  his  opening  remaiks  the  Professor  gave  further 
weight  to  the  law  of  discontinuity  of  variation,  of  which  the  previous 
lecturers  had  spoken.  A  hybrid  might  thus  be  as  stable  as  a  normal 
species.  Passing  to  the  consideration  of  pangenesis  as  spoken  of  by 
Darwin,  he  instanced  D.pacus  fullonum,  and  D.  sylvestris,  the 
twisted  stems  having  appeared  in  both  species,  although  they  were 
separated  by  several  hundred  yards.  He  believed  that  the  existence 
of  the  smooth  form  of  Lychnis  vespertina  was  due  to  the  pangenetic 
influence  of  L.  diurna.  The  offspring  of  a  cross  between  L.diurna 
and  L  v.  glabra  flowered  and  seeded  freely.  In  the  first  generation 
all  the  plants  were  uniform,  all  being  hairy,  and  of  the  type  of 
L.  diurna.  In  the  second  (generation  he  had  found  only  two-tliirds 
of  them  hairy,  and  they  were  furthermore  divided  into  broad-leaved 
forms  resembling  L.  diurna.  and  narrow-leaved  forms,  bearing  a 
likeness  to  L.  vespertina.  The  professor  then  described  at  some 
length  the  method  he  had  followed  to  artificially  produce  L.  d.  glabra,, 
and  he  claimed  that  he  had  thus  succeeded  in  transferring  thepangene 
of  latent  hairiness,  from  one  species  to  the  other. 
Hybridisation  and  its  Failures. 
Professor  Henslow  commence  1  his  lecture  upon  the  failures  of 
hybridisation  by  asking  what  he  averred  was  an  unanswerable 
question: — “Why  do  some  species  cross  and  give  fertile  offspring, 
and  others  refuse  to  do  so?”  This  question,  unanswerable  as  it  was, 
lav  at  the  bottom  of  all  practical  work.  Speaking  of  that  moot  point, 
What  constitutes  a  species?  the  reverend  gentleman  gave  as  his 
definition  that  “a  species  is  known  by  a  collection  of  presumably 
constant  characters  taken  from  all  parts  of  the  plant.”  It  was  not 
settled,  he  went  on  to  say,  how  many  characters  went  to  make  up  a 
species,  and  hei  e  arose  the  difference  between  the  Linnaean  and  the 
natural  systems  of  classification.  In  the  case  of  the  two  natural  orders 
Liliacese  and  Amaryliidaceae  one  difference,  that  of  the  superior  ovary 
of  the  former  order,  and  the  inferior  ovary  of  the  latter,  was  enough  to 
separate  them,  whilst  in  other  orders,  such  as  Saxifragacese,  superior 
and  inferior  ovaries  were  found  in  the  same  order.  Cattleya  with  its 
four  and  Laelia  with  its  eight  pollen  masses  were  so  closely  related  as 
to  cross  readilv,  as  would  also  the  allied  genera  Epidendnmi  and 
Sophronitis.  Was  the  hybridiser,  then,  to  upset  the  systematist,  or 
was  the  latter  to  stick  to  his  classification  even  if  the  groups  he 
separated  did  unite  ?  Dean  Herbert  said  that  if  one  species  crossed 
with  another  they  were  undoubtedly  one  and  the  same,  and  if  they 
would  not  cross  they  were  different  genera.  Rhododendron,  Azalea, 
and  Rhodora  would  all  cross  together,  and  yet  Rhodora  was  certainly 
very  different  in  appearance  from  the  other  two,  whilst  Rhododendron 
catawbiense  exhibited  many  points  of  difference  from  R.  jasminiflorum 
and  R.  javanicum.  The  same  might  be  said  of  Fuchsia  fulgens, 
F.  mageilanica,  and  F.  cylindracea,  the  last  named  having  dimorphic 
flowers.  It  was  manifest  therefore  that  the  systematist  and  the 
physiologist  could  only  agree  in  matters  of  classification  up  to  a 
certain  point.  The  Black  Currant  and  the  Gooseberry  had  been 
crossed,  also  the  Raspberry  and  the  Strawberry,  and  yet  no  cross  had 
been  effected  between  the  Show  and  Regal  and  the  Zonal  Pelargoniums ; 
moreover,  French  varieties  of  Zonal  Pelargoniums  would  not  cross 
with  English  "ones.  It  was  quite  possible  for  the  pollen  of  one  plant 
to  set  up  an  irritation  in  the  ovary  of  another  very  far  removed 
plant,  such  as  Fritillaria  and  Orchis,  but  although  the  pollen  tube 
had  the  power  to  enter  the  style  and  to  set  up  irritation  thefe  its 
potentiality  ceased.  Manv  ca-es  of  false  hybridisation  were  due  to 
this.  There  were  three  ideas  that  it  was  necessary  for  all  would-be 
hybridists  to  put  on  one  side — viz.  (1),  that  no  members  of  two 
families  would  cross  ;"(2)  members  of  different  cenera  very  rarely ; 
and  (3)  species  of  the  same  genus  very  easily.  Nature  would  not  be 
bound  down  by  these  rules,  or  any  system  of  classification. 
Experiments  in  Hybridisation  and  Cross-breeding. 
A  capital  paper  dealing  with  experiments  was  contributed  by  Mr. 
C.  C.  Hurst,  F.L  S.  Mr.  Hurst  commenced  by  saying  that  although 
most  breeders  were  of  opinion  that  certain  qualities  were  handed  on 
from  parent  to  offspring,  slight  variations  were  very  rarely  hereditary. 
Varietal  characters,  in  particular,  were  so  small  that  they  could  not  be 
traced  in  the  offspring,  whilst  specific  characters  were  observable.  In 
the  case  of  a  first  cross  between  two  species,  about  one-half  of  the  dis- 
