Am\priir'i909arm"}        Centenary  of  Charles  Darwin.  197 
zoology  incredibly  dull,  although  he  was  at  that  time  engaged  in 
collecting  and  studying  mineral  and  zoological  specimens,  and 
although  he  afterwards  attained  such  eminence  in  each  of  these 
sciences.  Darwin's  father,  learning  that  he  did  not  like  the  study 
of  medicine,  decided  that  he  should  fit  himself  to  be  a  clergyman, 
and  thus  after  two  years  at  Edinburgh  he  was  sent  to  Christ's 
College,  Cambridge.  Here  he  attracted  the  attention  of  Professor 
Henslow,  the  mineralogist  and  botanist,  who  became  his  "  dearest 
friend,"  directed  him  in  his  natural  history  studies,  and  aroused  in 
him  that  enthusiasm  which  characterized  the  remainder  of  his  career 
as  a  scientist. 
Through  the  reading  of  Humboldt's  "  Personal  Narrative " 
Darwin  acquired  a  desire  to  travel,  and  this  opportunity  soon  offered 
itself.  Professor  Henslow  not  only  used  his  influence  in  securing 
for  him  the  privilege  of  going  on  the  voyage  of  H.  M.  S.  Beagle 
as  naturalist  under  Captain  Fitz-Roy  on  a  surveying  tour  round 
the  world,  but  strongly  advised  him  to  do  so.  The  voyage  lasted 
from  December  27,  183 1,  to  October  2,  1836,  nearly  five  years,  and 
it  was  on  this  trip  that  Darwin  collected  so  much  of  the  material 
that  formed  the  basis  of  his  future  work  in  geology,  zoology,  and 
botany.  He  described  carefully  his  observations  each  day  in  his 
famous  Journal  of  the  Voyage,  and  altogether  it  is  no  wonder  that 
Darwin  looked  upon  this  voyage  as  the  most  important  event  in  his 
life  and  as  one  that  determined  his  whole  career. 
Then,  for  more  than  twenty  years  he  experimented,  and  pondered 
on  his  observations  and  those  of  others,  before  giving  his  final 
conclusion  to  the  world.  This  was  his  theory  of  natural  selection 
as  a  factor  in  organic  evolution,  and  his  discussion  of  this  subject  was 
set  forth,  as  already  pointed  out,  in  his  "  Origin  of  Species."  Darwin 
takes  as  his  starting  point  the  fact  that  in  the  lives  of  organic  beings 
there  is  a  struggle  for  existence,  and  that  those  which  survive  in 
this  struggle  are  those  possessing  some  favorable  qualities.  These 
qualities  arise  or  originate  as  slight  variations  or  modifications, 
which  are  transmitted  through  inheritance,  and  preserved  and 
accumulated  through  natural  selection.  That  is,  favorable  variations 
give  the  organism  an  advantage,  and  it  survives  and  they  are  pre- 
served or  perpetuated.  Thus,  through  gradual  modification  in  the 
course  of  time  new  varieties  and  species  come  to  be  recugnized 
Darwin  felt  that  if  natural  selection  was  one  of  the  factors  in 
evolution,  light  would  be  thrown  on  the  subject  by  careful  studies 
