656 
Climate  of  the  British  Islands 
monly  take  place  till  the  commencement  of  April.  Accordin<r 
to  the  slowness  or  rapidity  of  the  growth  of  the  different  kinds  of 
turnips  they  are  found  to  arrive  at  maturity  at  the  proper  time 
when  sown  at  different  seasons  from  the  middle  of  May  to  the 
early  part  of  July.  'I  he  effect  of  climate  on  the  cultivation  of 
turnips  then  is  readily  acknowledged  ; where  the  winter  tem- 
perature, or  at  least  the  temperature  of  some  month  in  the  year, 
does  not  fall  below  41°,  the  growth  of  turnips  cannot  by  the 
climate  of  that  place  be  checked,  therefore  the  turnips  must  be 
consumed  when  they  arrive  at  maturity,  taken  from  the  ground, 
or  allowed  to  run  to  seed.  But  as  turnips  when  taken  from  the 
ground  in  warm  climates  soon  lose  their  freshness,  and  at  the 
same  time  grass  and  other  food  can  be  grown  at  all  seasons,  it 
becomes  evident  that  turnips  will  in  such  places  only  be  cultivated 
for  consumption  when  they  arrive  at  their  full  growth,  and  will 
not  be  grown  for  the  purpose  of  being  preserved.  On  the  con- 
trary, where  the  winters  are  severe,  and  at  the  same  time  the  sum- 
mer temperature  favours  their  growth,  there  they  must  be  of  im- 
mense importance,  for  there  no  other  plant  will  grow  in  the 
same  space  of  time  so  large  a quantity  of  food  with  so  little  labour 
and  so  easy  of  preservation,  the  climate  itself  arresting  its  growth 
at  the  proper  time,  and  thus  preventing  the  trouble  of  reaping 
and  storing.  From  the  above  we  see  one  reason  why  the  cultiva- 
tion of  the  turnip  is  in  good  husbandry  so  essential  a feature  in 
Scotland  and  the  eastern  parts  of  England,  and  so  comparatively 
unknown  in  Ireland  and  the  south-west  of  England.  In  the 
former  situation  their  excellence  as  a substitute  granted  by  Pro- 
vidence for  the  natural  grasses  that  could  not  be  produced  in  winter 
in  sufficient  abundance  must  be  evident,  whilst  the  same  tempera- 
ture that  prevented  the  growth  of  grass  is  the  means  of  pre- 
serving the  turnips  in  a proper  state  for  food.  On  the  contrary, 
all  places  situated  south-west  of  the  line  of  41°  winter  cold,  have 
a natural  provision  of  winter  food  in  the  growth  of  the  grasses, 
whilst  the  same  mildness  of  temperature  that  allows  the  growth 
of  grass  would  also  allow  turnips  to  run  to  seed,  if  permitted  to 
remain  after  they  had  attained  their  full  growth,  and  consequently 
compel  their  consumption  or  removal  from  the  land.  Thus, 
whilst  the  necessity  for  their  growth  is  not  so  great,  their  value 
when  grown  is  also  less,  consequently  a point  must  arrive  when 
their  cultivation  will  cease  to  be  a part  of  good  husbandry 
It  is  the  province  of  others  to  point  out  to  what  extent  they 
should  be  cultivated  for  consumption  or  storing  under  these  cir- 
cumstances, and  to  show,  from  the  quantity  of  food  turnips  can 
produce  in  a given  time,  as  compared  with  other  descriptions, 
whether  or  no  they  should  be  preferred;  it  seems  sufficient  here 
to  show  that  turnips  are  affected  by  climate  in  the  preceding 
different  ways,  according  to  the  temperature.  But  from  the 
