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PEDIGREE  SEED  CORN. 
It  is  proposed  in  the  present  article  to  consider  the  following 
propositions  : — 
1.  Along  with  active  investigation  of  the  principles  of 
heredity  there  is  proceeding  considerable  increase  in  the 
number  of  varieties  and  races  of  the  cereals. 
2.  Some  existing  varieties  and  races  of  each  of  the 
cereals  have  been  well  proved  to  give  crops  of  much  higher 
value  to  the  grower  than  others  of  the  same  species,  and 
still  better  combinations  of  good  characters  in  new  races 
may  be  expected. 
3.  Definite  evidence  is  needed  of  the  suitability  of 
varieties  and  races  to  locations  and  soils,  and  in  this 
connection  the  cumulative  effects  of  natural  selection  in 
modifying  the  racial  character  of  the  cereals  must  be  taken 
in  account. 
4.  Much  better  comparisons  can  be  made  of  both  yield 
and  quality  between  distinct  varieties  and  pure  races  than 
between  aggregates  of  fluctuating  composition. 
5.  It  is  desirable  to  consider  whether  a scheme  of 
co-operative  and  co-ordinated  trials  in  difi'erent  localities 
of  existing  varieties  and  of  new  pure  races  of  the  cereals 
as  they  appear,  and  also  a system  of  registration  of  them 
would  have  advantages  alike  to  plant  breeders,  seed  distri- 
butors, and  growers. 
A considerable  proportion  of  the  seed  corn  used  in  the 
United  Kingdom  consists  of  mixtures  of  many  varieties  and 
races. 
In  some  parts  of  the  country  these  mixtures  result  in 
aggregates  of  more  or  less  well-marked  types.  For  instance, 
most  of  the  barley  grown  north  of  the  Tay  is  such  a mixture 
of  races  known  as  “ Scotch  Common,”  whilst  in  some  parts 
of  Ireland  a not  very  dissimilar  aggregate  known  as  “ Old 
Irish  ” is  grown.  Such  similarity  as  different  growths  of  these 
so-called  “ varieties  ” present  are  doubtless  the  result  of  the 
exchange  of  seed  corn  being  generally  limited  to  the  district 
or  to  prolonged  cultivation  under  approximately  similar 
external  conditions.  In  other  words,  these  aggregates  have 
become  what  they  are  at  present  mainly  by  the  action  of 
natural  selection.  We  may  call  them  “ local  varieties,”  at 
the  same  time  remembering  that  the  term  “ variety  ” has 
