Frb.  r,  1896.1 
I'HK  'I'KOPICAI 
AGRir:Uf/njf<is  r. 
5*3 
jected  to  their  nonnal  growing  conditions,  ilie_y  could 
Inirdly  be  weakened  i>y  losing  their  ri'st  ; Ihongli,  on 
llie  other  liand,  it  ninst  he  assuniod  tliat  some  subtle 
recuperative  process  is  going  on  in  resting  plants 
akin  to  that  which  renews  animal  vigour  during 
sleep,  or  otherwise  the  shortening  of  the  period  of 
rest  could  hardly  he  so  detrimental  as  it  is,  even 
when  favourable  conditions  for  growth  accompany 
the  re-awakening. 
With  regard  to  Antipodean  plants  which  have  long 
been  introduced  into  ibis  country,  such  as  the  New 
Zealand  Todeas  snperba  and  pellucida,  they  have 
fully  adapted  themselves  to  our  climate,  and  rise  in 
our  early  spring  at  preeisel}’  the  time  when  at  home 
their  growth  would  be  ceasing.  How  long,  liowcver, 
such  a change  takes  to  establish,  we  do  not  know. 
Amongst  our  native  Ferns  we  have  noted  a certain 
obstinacy  in  retaining  the  home  periodsofawakening 
deciduous  jt.thyria  found  in  Scotland,  starting  into 
growth  a week  or  two  later  than  southern  finds  even 
after  years  of  culture  under  like  conditions.  Poly- 
podium  vulgare,  especially  in  its  varietal  foinis, 
dematnls,  curiously  enough,  .a  much  longer  period  of 
rest.  01'  rather  starts  int.o  grcwtli  under  glass  very 
much  later  tlian  normal  plants  in  native  liabitat.s, 
Tliey  often,  indeed,  sliosv  no  trace  of  starting  under 
glass  nntil  July  or  even  August,  and  this  with  per- 
fectly cold  cniture,  so  that  the  lateness  of  their 
starting  is  not  to  be  attributed  to  growth  un- 
naturally maintained  by  warmth  long  after  the  normal 
dormant  period  should  begin.  This  case  is  unique 
in  our  experience,  culture  under  glass  inducing,  as 
a rule,  and  as  one  would  expect,  a somewhat  earlier 
development  than  out-of-doors.  Seedlings,  as  a rule, 
are  more  precocious  in  their  growth  than  old  plants, 
and  quite  deciduous  Ferns,  like  Athyria,  with  very 
little  warmth  indeed,  will  the  first  year  retain  their 
fronds  i-ight  through  the  winter,  though  later  nothing 
will  prevent  them  dying  down  in  the  normal  way  in 
autumn.  We  have  found,  however,  that  even  in  a 
few  g>  noratious,  it  is  possible,  by  selective  culture 
under  glass,  to  considerably  lengthen  the  growing 
period  of  Athyriums,  shortening  the  dormant  period 
in  equal  measure.  Most  of  the  plumose  superbum 
section  of  this  species  remain  quite  green  for  fully 
a month  after  all  their  immediate  progenitors  in 
the  same  house  have  withered  entirely  down.  One 
form,  indeed  (A.f.-f.  plumosum,  Druery),  is  perfectly 
green  at  the  time  of  writing  (end  of  November), 
and  has'been  so  at  Christmas;  while,  on  the  other 
hand,  without  any  stimulus  beyond  its  own  inherent 
robustness,  it  rises  into  active  growth  a full  month 
before  its  fellows.  One  year,  indeed,  a robust  growth 
started  on  Dec.  2,  before  the  old  fronds  had  even 
turned  colour,  but  frost  immediately  after  stopped 
its  progress. 
It  would  almost  seem  by  this  case  that  further 
selections  might  eliminate  at  one  iiud  the  same  time 
the  deciduous  nature  of  the  species,  and  the  dormant 
period  also ; this  latter  being  decidedly  reduced  one- 
half  in  two  generations,  and  nearly  as  much  in  one, 
since  its  parent  is  not  far  behind  it  in  the  long 
retention  of  its  vei'dure,  while  the  grandparent  growing 
by  their  side,  dies  down  as  early  and  as  thoroughly 
as  any  Athyrium  we  are  acquainted  with. 
How  long  the  actual  dormant  period  is,  as  com- 
pared with  the  apparent,  is  an  open  question,  as 
well  as  that  of  the  recuperative  or  strengthening 
processes  which  undoubtedly  accompany  them.  The 
roots  certainly  commence  to  be  active  long  before 
there  is  any  sign  of  life  in  the  crown.  Hyacintli 
bulbs  grown  in  glasses  arc  a familiar  exemplification 
of  this ; and  as  regards  Ferns,  even  in  the  depth  of 
winter  the  crowns  will  he  seen  to  be  fattening  up, 
implying  groat  root  activity  and  preparation  for  the 
coming  rapid  growth  in  the  spring.  It  is  highly 
probable,  therefore,  that  in  most,  if  not  in  iillcises, 
much  of  the  dormancy  is  more  apparent  than  real, 
and  that  a good  deal  of  secret  and  subtle  work  is 
being  done,  of  which  we  Know  little  or  nothing,  but 
the  n eed  for  which  is  evidenced  by  the  weakness 
subsequently  shown  when  the  dormant  period  is 
unduly  curtailed,  and  these  processes  are  interfered 
with. — Chas.  T.  Dme^-y,  F.L.S. — in  Gardeners'  Chroniclei 
(iA.s-id,\ii':  AS  A manhim:. 
I note  with  sotnn  intoiest  what  Mr.  John  liainheit 
statn.s  in  )'cfoi'oncc  Lo  the  use  of  g.as-liine  as  an 
antidote  for  club  in  Cahhage.s,  and  for  the  extir- 
pation of  wirewoiiii.  In  lecturing  to  cottage  and 
allotment-holders,  many  complaints  are  made  as 
to  the  ravages  of  the  wirewona,  and  the  occur- 
i-ence  of  clubbing  in  Cabbages  and  Cauliflowers. 
If  I understand  Mr.  Hambert  rightly,  he  recommends 
the  use  of  gas-lime  in  a crude  state,  just  asitcoiue.s 
fi'oin  the  gaswoi'ks.  It  is  tine  that  he  recommends 
its  applic.ition  in  very  small  propoitions,  but  I have 
mot  with  allotment-holders  who  have  applied  it  to 
tlieir  land  just  in  the  form  in  which  it  is  received 
from  the  works,  and  then  found  it  very  ditlicult  to 
grow  an}  thing  on  the  land  for  a year' or  two.  It 
is  no  doubt  a useful  agent,  dcstinctivc  to  insect-life 
when  used  as  recommendel  by  Mr.  Lambert;  but 
niy  fear  is,  lost  some  might  put  too  large  a con- 
struction upon  his  words,  and  apply  it  unwiselv.  and 
with  unfortunate  etfccts.  Mr.  \V.  C.  Watson,  in  bis 
admirable  ]iaper  on  •' Manures  and  their  Cses." 
tcMs  ns  that  gas-lime  “is  a inixtnie  of  calcinm 
hydrate  and  calcimn  carbon.-ito,  witli  siiiphito  of  lime, 
'I’lio  two  latter  compounds  aie  in  tbemselvp.s 
poisonous  to  plant-life,  but  tbo}'  :nv  lioih  converted 
into  gypsnin  or  sulphate  of  linu'  (a  plant-food),  bv 
cx\)osingUie  g.is-liine  to  the  action  of  the  almospbere.'" 
It  may  and,  I fear,  docs  happen,  that  when  gas-liine 
is  applied  in  a crude  state  as  received  from  tlia 
gasworks,  the  two  compounds,  poisonous  to  plant-life, 
are  present  in  undue  proportions  in  the  interests  of 
safety,  hence  the  unfortunate  results  which  I have 
heard  allotment-holders  deplore.  Mr.  Watson  further 
states  : — “ To  prepare  fresh  gas-lime  for  use  in  the 
garden,  it  may  be  spread  out  on  a layer  of  pondmud, 
night-soil,  or  coarse  vegetable  refuse,  and  exposed 
to  rain  * and  air.”  This  I hold  to  be  sound  and 
necessary  advice.  If  put  on  cleared  land  in  the 
autumn,  it  can  be  laid  upon  the  surface  at  the  rate 
of  10  lb.  or  so  per  rod,  but  it  should  lie  on  the 
surface  for  several  weeks  before  being  forked  in, 
taking  care  that  it  is  distiibuted  equally  through  the 
soil.  It  is  undoubtedly  a powerful  remedial  agent 
in  clearing  land  of  insect  life,  but  needs  to  be 
applied  with  caution.— R.  D.  [It  is  doubtless  safest 
to  use  gas-lime  after  some  weeks’  exposure  in  the 
open  for  surface-dressing,  or  when  applying  it  to  land 
dug  to  one  spit  in  depth  ; but  in  the  case  of  dressing 
the  bottom  soil  in  trenching  and  incorporating  with 
the  top  spit,  which  is  usually  thrown  into  the  bottom 
of  the  trenches  in  the  small  quantities  recommended 
by  Mr.  Lambert,  no  harm,  but  rather  good,  would 
result  from  the  use  of  gas-lime  in  the  f.vesh  state. 
Ed.J  — GardenerH’  Chronicle. 
NOTES  ON  THE  EliNCTIONS.  COMPOSI- 
T I O N AND  I A)  A T’  1 0 N O E M A N U U E.S. 
Rv  Douob.ts  A.  Oii.cmnsT,  R.,Sc. 
Rrietiy  stated,  the  following  are  the  functions  of 
manures :—{(()  In  many  cases  manures  improve  the 
physical  and  mechanical  condition  and  the  texture 
of  the  soils  to  which  they  are  applied.  Thus  lime 
when  applied  to  sour  land  decomposes,  and  there- 
fore renders  harmless  the  sour  organic  acids,  w'hose 
presence  in  the  soil  is  the  cause  of  the  sour  or 
acid  condition  of  the  land.  When  farmyard  manure 
is  applied  to  land,  the  texture  and  physical  condition 
of  the  soil  is  much  improved  by  the  organic  matter 
of  which  this  manure  is  largely  composed.  (/U  In 
many  cases  manures  act  on  plant  food  already 
pre.sent  in  the  soil,  and  convert  this  plant  food  int'o 
such  a condition  that  it  can  he  absorbed  by  the 
roots  of  plants.  The  maiuirial  value  of  lime  is  due 
principally  to  the  action  of  this  manure  on  the  food 
of  plants  already  piesent  in  the  soil.  (,■)  The  most 
important  function  of  inauiires  is  to  supply  plant 
food  necessary  for  tlie  giowth  of  crops,  which  is 
deficient  in  the  soil. 
The  necessary  ennstitnonts  of  plant  fond  that  are 
generally  deficient  in  soils  are  nitrogen,  phosphoric 
acid,  and  potash. 
Nitrogen  occurs  in  monnres  as  ; — (a)  Nitrates,  e.g 
nitrate  of  soda,  (h)  Ammonia  salts,  e.g.,  sulphate 
of  ammonia,  [c)  Organic  nitrogen,  e.g.,  dried  blood. 
