Miscellaneous  Plant  Diseases. 
269 
From  the  same  source  diseased  parsley  was  sent.  It  was 
caused  by  the  fungus  Peronospora  nivea  Unger,  described  and 
figured  in  last  year’s  Report.  The  methods  of  dealing  with 
the  disease  were  given  and  a copy  of  the  Report  was  forwarded 
to  the  inquirer.  Last  year,  as  reported,  this  disease  made  its 
appearance  in  various  places  in  Norwood.  In  one  place,  a plot 
where  the  parsley  was  completely  destroyed  in  the.  early  spring, 
the  soil  was  drenched  with  a 6 per  cent,  solution  of  copper 
sulphate.  After  a week  or  two  the  parsley  was  sown  and  a 
healthy  ci’op  was  obtained.  In  a neighbouring  locality  nothing 
was  done  and  the  disease  appeared  worse  than  before,  blighting 
and  bleaching  the  leaves  of  the  whole  bed.  One  morning  the 
bed  was  sprayed  with  a 16  per  cent,  solution  of  sulphate  of 
iron  with  the  effect  that  the  whole  foliage  was  killed  right 
down  to  the  roots,  but  after  a while  the  roots  sent  out  new 
shoots,  and  the  second  growth  was  quite  healthy, 
A fungus  of  the  same  group  has  been  frequently  observed 
this  year  on  the  seed  pods  of  stock  and  wallflowers.  It  was 
identified  as  Peronospora  parasitica  de  Bary  (see  Fig.  1.  w to  Y, 
page  262),  a disease  attacking  various  cruciferous  plants.  It 
penetrated  the  outer  skin  of  the  pods  and  killed  the  portions 
underneath,  causing  swellings  and  twistings  of  the  pods.  Of 
course  no  seeds  were  developed.  On  searching  the  neighbour- 
hood of  the  diseased  plants,  a common  weed  (shepherd’s  purse) 
was  found  badly  attacked  by  the  same  fungus.  It  is  a well- 
known  disease  on  this  plant,  and  no  doubt  this  was  the  source 
whence  the  infection  spread.  Care  should  be  taken  that  no 
diseased  plants  of  shepherd’s  purse  are  permitted  to  remain. 
The  diseased  portions  on  the  cultivated  plants  must  be  removed. 
Some  diseased  plants  received  were  found  to  be  attacked  by 
insects  and  sent  on  to  the  Society’s  Zoologist ; and  others  that 
had  suffered  from  some  physical  or  mechanical  causes,  and 
need  not  be  further  referred  to. 
A communication  as  to  a disease  on  cucumbers  has  been 
received  fi’om  Professor  Maze,  of  the  Pasteur  Institute,  Paris, 
which  it  is  desirable  should  be  published  in  the  Journal. 
As  the  disease  has  been  under  investigation  by  my  assistant, 
Mr.  Giissow,  for  some  months,  he  has,  at  my  request,  added 
a note  giving  the  results  of  his  investigations,  and  a di’awing 
of  the  fungus. 
The  Laboratory, 
44  Central  Hill,"  Norwood,  S.E. 
William  Carruthers. 
