May  22,  1902. 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
445 
Odontoglossum  crispum  var.  Robert  McVittie. 
At  the  Drill  Hall  meeting  of  the  Royal  Horticultural  Society, 
held  on  April  22,  a  first-class  certificate  was  accorded  to  this 
variety,  sent  by  W.  Thompson,  Esq.  (gardener,  Mr.  Stevens), 
Walton  Grange,  Stone.  The  flowers  are  large,  but  not  parti¬ 
cularly  handsome;  it  is  one  of  the  O.  c.  apiatum  class.  All  parts 
are  alike,  bearing  a  very  heavy  reddish-chocolate  blotch,  and  well 
balanced  in  size.  The  form  is  good.  Our  illustration  is  from  a 
sketch  by  Mr.  Geo.  Shayler. 
The  WeeK’s  Cultural  Notes. 
The  Whip  Orchid,  as  Scuticaria  Steeli  is  sometimes  called,  is 
not  one  of  tW  most  showy,  but  it  is  a  very  interesting  species. 
The  long  pendant  leaves  and  small  flowers  clustering  at  their 
bases  are  very  grotesque  and  quaint,  while  individually  the 
blossoms  are  very  beautiful.  This  plant  delights  in  a  very  strong 
heat  and  ample  light  and  moisture.  A  good  place  to  grow  it  is 
the  back  or  end  wall  of  an  East  Indian  house,  close  up  to  the 
light,  and  where  it  obtains  a  full  share  of  sun. 
Cork  blocks,  with  a  little  sphagnum  about  the  roots,  are 
better,  perhaps,  than  baskets  for  it,  as  there,  is  nothing  to  obstruct 
the  passage  of  the  leaves.  Anything  touching  the  point  of  these 
leaves  while  growing  is  sure  to  be  productive  of  mischief,  leading 
Odontoglossum  crispum  var.  Robert  McVittie. 
to  browning  of  the  tips  and  consequent  weakness.  The  present  is 
a  good  time  to  attend  to  the  compost,  adding  a  little  new  moss 
where  necessary,  and  in  cases  where  new  blocks  are  needed, 
allowing  those  of  sufficient  size  to  last  the  plants  for  several 
years.  After  disturbance  at  the  root,  little  root  moisture  is 
required ;  but  healthy  established  specimens  must  be  kept  very 
moist  while  growing. 
All  the  small  block  plants,  too,  such  as  Trichocentrums,  small 
tessle-leaved  Oncidiums,  Sophronitis  cernua  and  S.  violacea, 
lonopsids,  and  others,  should  now  be  seen  to,  and  the  roots  given 
fresh  matei'ial  where  necessary.  A  little  attention  every  season, 
removing  any  dead  stems  or  sour  decayed  moss,  substituting 
new  for  it,  and  fastening  any  portion  that  may  have  broken 
loose,  is  Avell  repaid  by  tbe  increased  health  of  the  plants.  All 
such  should  be  regularly  dipped  now,  as  they  need  watering — 
not  have  the  water  poured  on  by  means  of  a  can,  as  this  often 
fails  to  reach  all  the  roots.  A  thorough  submerging  drives  the 
air  out  from  the  latter,  to  be  replaced  by  fresh,  and  also  reaches 
everf  part  of  root  and  compost. 
Saccolabinms,  .Vngrsecums  of  small  stature,  Phalsenopsids, 
Aerides,  and  the  like,  are  now  growing  very  freely,  and  must  not 
be  checked  in  any  way.  Keep  the  foliage  well  sponged  and  free 
of  insects ;  attend  to  any  small  matters  of  compost  not  already 
done,  and  remember  that  a  steady  progress  in  a  regular  ten.pera- 
ture  is  what  these  delight  in.  Growth  may  be  rushed  along 
quickly  in  strong  heat,  but  too  often  the  leaves  produced  under 
these  circumstances  fall  off  in  autumn  or  winter. — H.  R.  R. 
Insectivorous  Plants. 
Mr.  O’Neill,  of  Dublin,  lately  gave  a  lecture  on  this  subject 
before  the  Irish  Gardeners’  Association.  His  descriptions 
throughout  were  characterised  by  a  tasteful  literary  and  graphic 
style  which  quite  charmed  his  audience.  After  a  few  introduc¬ 
tory  remarks,  the  lecturer  proceeded  to  dilate  on  the  slides  show¬ 
ing  the  Sundew  and  Butte rwort  growing  in  boggy  land,  and  the 
Sundew  with  gland,  fringed  leaf,  and  the  stamens  and  pistil. 
With  regard  to  the  tentacles  on  the  leaf  of  Sundew,  he  said  : 
When  set  in  motion,  the  tentacles  are  known  to  be  inflected  at 
an  angle  of  45deg  to  90deg  for  from  two  to  three  minutes.  These 
tentacles  exude  a  sticky  substance,  and,  owing  to  the  insect’s 
body  being  composed  of  spiracles  or  air-breathing  pores,  the  fly 
soon  dies,  and  is  gradually  transferred  to  the  centre,  where  the 
digestive  fluid  is  secreted,  and  gradually  absorbed.  Regarding 
the  sensitive  nature  of  tbe  tentacles,  he  mentioned  that  they 
were  by  far  more  sensitive  than  the  nerves  of  the  tip  of  the 
tongue,  a  piece  of  a  hair  l-120th  part  of  an  inch  having  inflected 
them.  Regarding  the  power  of  digesting  possessed  by  these 
plants,  a  quotation  from  Charles  Darwin’s  volume  is  apropos. 
Three  cubes  of  white  translucent  extremely  tough  cartilage  were 
cut  from  the  end  of  a  slightly  roasted  leg  bone  of  a  sheep.  These 
were  placed  on  three  leaves  borne  by  poor  small  plants  in  my 
greenhouse  during  November,  and  it  seemed  in  the  highest  degree 
improbable  that  so  hard  a  substance  would  be  digested  under 
such  unfavourable  circumstances  ;  nevertheless,  after  forty-eight 
hours,  the  cubes  were  largely  dissolved  and  converted  into  minute 
spheres  surrounded  by  transparent,  very  acid  fluid.  Two  of 
these  spheres  were  completely  softened  to  their  centres,  whilst 
the  third  still  contained  a  very  small  irregularly  shaped  core  of 
solid  cart-ilage.  Their  surfaces  were  seen  under  the  microscope 
to  be  curiously  marked  by  prominent  ridges,  showing  that  the 
cartilage  had  been  unequally  corroded  by  the  secretion.  I  needl 
hardly  say  that  cubes  of  the  same  cartilage  kept  in  water  for 
some  len^h  of  time  were  not  in  the  least  affected.  After  being 
fed,  the  secretion  stops  and  permits  the  undigested  portion  being 
blown  away.  They  sometimes,  however,  kill  themselves  by  eating 
too  much.  On  being  given  glass  and  chemical  substances  (phos¬ 
phate  of  ammonia,  one- twentieth  millionth  part  caused  inflection), 
to  test  inflection  it  was  found  that  although  they  responded,  they 
soon  released  their  grasp,  thus  showing  a  power  of  discrimination. 
In  mentioning  that  the  gland  of  Drosera  was  filled  with  a| 
purple  fluid,  which  enables  it  to  secrete  an  acid  and  a  ferment, 
the  lecturer  said  proof  of  tbis  was  found  in  the  fact  that  thq 
purple  changed  into  a  specked,  or  mottled  hue,  showing  the 
absorption  of  protoplasm  of  the  fly  into  a  soluble  form,  and  the 
reason  of  devouring  same  to  be  the  acquisition  of  nitrogen.  The 
varieties  of  Drosera,  are  the  round-leaved  great  Sundew  and  long¬ 
leaved  Sundew,  which,  according  to  an  authority,  look  like  crowds 
of  pea”ls  scattered  over  a  fairy  carpet  of  rubies.  The  next  slide 
showed  Drosera  capensis,  a  native  of  South  Africa,  capturing 
insects.  The  roots  of  these  plants  are  very  delicate,  and  in  fact 
suckers,  so  as  to  enable  it  to  get  sufficient  moisture  to  enable  it 
to  keep  up  the  supply  of  gummy  secretion. 
Venus’s  Fly  Trap. 
Venus’s  Fly  Trap  (Dionsea  muscipula),  which  was  next  deaii 
with,  is  a  native  of  a  narrow  strip  of  country’  in  the  east  of  North 
America,  from  Long  Island  to  Florida,  and  generally  grows  in 
the  vicinity  of  peat  bogs.  The  leaves  lie  on  the  ground,  and 
the  end  of'  the  leaf  is  divided  into  two  parts  and  hinged,  while 
along  the  edges  are  from  twelve  to  twenty  teeth.  These  do  not 
carry  glands,  but  in  the  centre  are  three  erect  spines  which  are 
extremely  sensitive.  Describing  the  leaves  of  Venus’s  Fly  Trap, 
Mr.  O’Neill  said  they  were  a  little  concave,  the  teeth  interlock, 
and  so  the  prey  was  killed  by  crushing.  Cheese  did  not  agree 
with  the  leaves,  and  killed  them.  The  teeth  overlapped,  an.l 
so  there  was  no  fear  of  smashing  them.  In  a  lecture  given  by 
Dr.  Burdon  Sanderson  many  years  ago,  refoaring  to  this  plant 
he  says  :  “  When  we  call  this  process  digestion,  we  have  a  definite 
meaning — we  mean  tliat  it  is  of  the  same  nature  as  that  by  which 
we  ourselves,  and  the  higher  animals  in  general,  convert  the 
food  they  have  swallowed  into  a  form  and  condition  suitable  to 
be  absorbed,  and  thus  available  for  the  maintenance  of  bodily 
life.  We  will  compare  the  digestion  of  Dionsea  with  that  which 
in  man  and  animals  we  call  digestion  proper,  the  process  by 
which  the  nitrogenous  constituents  of  food  are  rendered  fit  for 
absorption.  This  takes  place  in  the  stomach.  It  also  is  a  fer- 
iiientatiom  namely,  a  chemical  change  effected  by  the  agency  of 
a  leaven  or  ferment  which  is  contained  in  the  stomach  juice,  and 
can  be,  like  the  ferment  of  saliva,  easily  separated  and  prepared. 
As  so  separated  it  is  called  pepsin;  consequentlv,  |^amng  the 
ferment,  we  can  easily  imitate  digestion  out  of  the  body,  ror 
this  experiment  tliere  are  three  things  necessary  :  (1)  That  our 
liquid  should  contain  pepsin;  (2)  that  it  should  be  slightly  acid: 
(3)  that  it  should  be  kept  at  the  temperature  of  incubation,  about 
97deg  F.  We  .select  for  the  experiment  a  substance  wine’  . 
although  nutritious  and  containing  nitrogen,  is  not  easdv 
digsted.  such,  for  example,  as  boiled  white  of  egg  in  water  con¬ 
taining  a  small  percentage  of  hydrochloric  acid  and  a  trace  of 
