337 
# 
IHlotes  anb  Commuiucations. 
EXPERIMENTS  WITH  WHEAT  AND  BARLEY 
HYBRIDS  ILLUSTRATING  MENDEL’S 
LAWS  OF  HEREDITY. 
Mendel’s  original  communication  on  Experiments  in 
Hybridisation  was  presented  to  the  Briinn  Society  in  the 
year  1865.  At  this  period  the  study  of  problems  in  heredity 
was  receiving  far  more  attention  than  it  has  had  since.  Never- 
theless, although  a detailed  account  of  his  experiments  was 
published  shortly  afterwards  in  the  Verh.  naturf.  Ver.  in 
Briinn  Ahhandlungen,  IV.,  1865,  judging  from  the  almost 
absolute  lack  of  reference  to  it  by  later  writers,  it  was  com- 
pletely lost  sight  of.  It  was  not  until  1901,  that  attention  was 
again  called  to  this  woi’k  by  the  practically  simultaneous  re- 
discovery, by  De  Vries,  Correns,  and  Tschermak,  of  the  laws 
Mendel  enunciated.  Hitherto  much  of  our  knowledge  of  the 
laws  of  heredity  had  been  derived  from  the  experiments  of 
breeders  working  to  a large  extent  from  an  agriculturist’s 
point  of  view.  This  work  led  to  no  generalisations  of  lasting 
importance,  but  to  many  fanciful  theories.  The  student  need 
only  consult  the  mass  of  data  accumulated  in  Darwin’s 
Animals  and  Plants  under  Domestication,  or  Focke’s  Pjlanzen- 
mischlinge,  to  realise  how  chaotic  the  whole  subject  was. 
Mendel,  by  means  of  a single  series  of  experiments,  found 
the  clue  which  has  elucidated  many  of  these  mysteries  and 
opened  up  lines  of  research  that  bid  fair  to  give  us  more 
command  over  nature  than  breeders  some  five  years  back 
dared  to  dream  of. 
In  his  original  paper  he  tells  us  that  he  was  struck  by  the 
regularity  with  which  the  same  forms  appeared  in  crosses 
between  the  same  species,  and  realising  the  importance  of  the 
phenomenon,  he  started  to  investigate  it.  At  the  oiitset  he 
saw,  that  in  spite  of  the  mass  of  researches  which  had  accumu- 
lated at  that  time,  there  was  no  series  of  experiments  available 
from  which  the  actual  number  of  different  forms  occurring 
among  the  progeny  of  a cross-bred,  or  their  numerical  relation- 
ships, could  be  ascertained.  No  one  had  grasped  the  necessity 
of  following  out  in  detail  the  descendants  of  each  individual 
cross-bred,  or  their  descendants  in  turn.  On  the  contrary  they 
VOL.  65.  Z 
