32 
On  the  Climate  of  the  British  Islands 
Thus  in  the  warmest  region  of  these  islands,  and  where  the 
highest  winter  temperature  exists — on  the  south-west  of  Ireland 
— twelve  or  more  species  of  plants  occur  in  a wild  state,  which 
are  natives  of  the  north  of  Spain. 
On  the  south-west  of  England  and  south-east  of  Ireland  a 
vegetation  exists  intimately  related  to  that  of  the  coasts  of  Nor- 
mandy and  Brittany,  and  not  found  elsewhere  in  the  British 
Isles. 
On  the  elevated  hills  of  Wales,  Scotland,  and  some  of  the 
highest  points  of  Ireland,  the  plants  entirely  differ  from  those  of 
the  low  lands,  and  are  analogous  to  the  vegetation  of  Scandinavia, 
and  the  Alps.  In  the  high  regions  of  Scotland  the  grouse,  the 
ptarmigan,  and  the  Alpine  hare  are  found  in  the  several  zones  of 
temperature  for  which  nature  has  fitted  them. 
The  Germanic  type  forms  the  predominating  vegetation  of  the 
kingdom,  occurring  alone  or  in  common  with  groups  of  other 
plants.  “ All  plants  universally  diffused  in  these  islands  are 
German.”  (Forbes.) 
On  the  south-west  coast  of  England  greenhouse  plants  flourish 
with  less  care  than  in  other  places,  and  myrtles,  geraniums,  and 
other  tender  exotics  are  constantly  exposed  during  the  winter,  and 
flower  well  the  following  summer.  A considerable  number  of 
plants  from  New  Holland,  and  New  Zealand,  were,  as  an  experi- 
ment, forwarded  by  the  late  Mr.  Aiton  of  Kew  Gardens,  to 
Penzance,  where  they  have  flourished  in  the  open  air  for  many 
years. 
73.  Effect  of  Climate  on  the  Growth  of  Corn. — The  produc- 
tion of  bread-corn  is  a primary  element  of  agricultural  and 
national  prosperity,  and  never  was  the  question  of  the  relative 
effects  of  climate  on  the  growth  of  wheat  so  important  as  at  the 
present  moment.  Apart  from  all  political  and  party  considera- 
tions, this  view  of  the  case  must  force  itself  by  its  practical  bear- 
ing on  the  corn-growers  of  this  kingdom.  I therefore  feel  that  I 
am  entering  on  a question  which  requires  to  be  examined  with  the 
utmost  care  and  impartiality,  that  theoretical  inferences  should 
be  avoided,  and  no  conclusions  drawn  but  what  well-established 
facts  will  justify.  I have,  therefore,  with  much  labour,  collected 
and  arranged  the  Tables  of  Temperature,  Rain,  and  Moisture, 
which  accompany  this  essay.  And  most  fortunately  at  this 
juncture  the  thermometrical  observations  made  at  the  apartments 
of  the  Royal  Society  from  1774  onwards,  have  been  reduced  by 
Mr.  Glaisher,  and  published  in  the  last  issue  of  the  “ Transac- 
tions” of  the  Society.  The  limits  of  this  essay  will  only  permit 
a very  restricted  use  of  these  most  valuable  Tables ; those  who 
may  desire  further  information  on  the  subject  will  do  well  to 
consult  these  facts  so  admirably  arranged  by  Mr.  Glaisher. 
