262       CULTIVATION  OF  CINCHONA  PLANTS  UNDER  GLASS. 
her  operations  ?*  and,  after  all,  what  are  these  ?  and  what  is 
life  ?  Whoever  watches  the  manner  in  w^hich  nature  acts  the 
aedile  with  her  cells — diruit,  sedificat,  mutat  quadrata  rotun- 
dis  ") — will  think  little  of  the  cell  itself,  and  much  of  that  which 
it  contains.  If  I  take  in  my  hands  a  brick,  I  have  a  specimen 
of  material  by  which,  through  adding  brick  to  brick,  the  four 
walls  of  a  house  may  be  constructed  ;  but  I  should  not  be  able 
thence  to  reason  out  the  nature  of  the  stirring  active  life  which 
those  boundary  walls  might  contain.  The  addition  of  brick  to 
brick  might  very  well  illustrate  the  phenomena  of  crystalliza- 
tion, but  the  activities  of  life  within  the  plant  much  more  re- 
semble the  course  of  reconstruction  of  a  great  city  like  Paris,  in 
which  an  imperial  will,  availing  itself  of  the  all-arranging  genius 
of  a  subordinate  functionary,  acts  for  the  good  of  the  whole, 
and,  caring  little  for  the  four  walls,  or  for  any  number  of  them, 
if  standing  in  the  way  of  its  well-devised  projects,  adapts  the 
materials  even  of  previous  structures  to  the  exigencies  of  the 
new  thing  that  has  to  be  produced ;  and  who  will  deny  that  the 
result  is  admirable  ? 
It  is  thus  that  practical  experience  in  cultivation  leads  to  the 
review  of  theories  which  must  be  cast  aside  when  they  have 
served  their  turn,  or  demolished  when  they  stand  in  the  way  of 
real  science,  which  means  knowledge,  and  not  speculation. 
In  the  address  of  the  President  I  observe  with  pleasure  the 
remark  that  "a  country  stroll  of  half  an  hour  will  yield  material 
for  thought  and  investigation  available  for  many  a  day;"  and 
may  we  not  extend  the  application  of  the  lines  which  he  has 
quoted  to  the  more  difficult,  but  not  less  remunerative,  objects 
of  study  presented  by  the  cultivation  of  plants  in  circumstances 
so  different  to  those  of  their  native  habitat  ?  The  very  difficul- 
ties we  encounter  are  a  source  of  pleasure  in  overcoming  them^ 
and  enable  us  to  appreciate  more  fully  that  infinitely  varied 
Wisdom  which  has  appointed  everything  beautiful  in  its  season, 
and  all  things  in  measure  and  number  and  weight.  JVo  quid 
nimus  is  a  golden  rule  for  every  one  that  attempts  to  cultivate 
*See  "Chemismus  der  Pflanzenzelle,"  von  Dr.  H.  Karsten,  Wein, 
1869,  pp.  5,  6,  etc. 
