6o8  Botany  and  Materia  Medica.         {Av£^£%T ' 
Deviation  in  "^ro^  J'  ^"  Arthur,  The  American  Naturalist, 
Development  Due  September,  1895,  P-  8o4>  regards  maturity  as 
to  the  Use  applying  to  the  seed  as  a  whole  and  viability 
of  Unripe  Seed.  ^0  t^e  embryo,  the  physiological  processes 
associated  therewith  being  quite  distinct.  The  author  shows  from 
personal  experiments,  as  well  as  from  recorded  work  of  others,  that 
considerable  number  of  seed  from  unripe  fruit  will  germinate  so 
that  viability  precedes  maturity.  The  writer  holds  that  a  seed  is 
simply  a  young  plant,  enclosed  in  a  protective  covering,  and  accom- 
panied by  surplus  nutriment.  The  resting  condition  of  a  seed  is 
not  essential  to  germination,  but  is  purely  incidental  and  designed 
to  aid  in  distribution. 
The  seed  and  sometimes  the  associated  parts  of  the  fruit  will  con- 
tinue to  develop  under  circumstances  which  put  a  stop  to  all 
growth  in  the  vegetative  parts.  This  phenomenon  is  known  as 
after-ripening.  There  are  marked  deviations  from  normal  develop- 
ment in  plants  from  immature  seed.  The  seedlings  are  weaker,  the 
rate  of  germination  is  generally  slower  and  the  plant  is  less  able  to 
withstand  unfavorable  conditions.  In  plants  from  green  seeds  there 
is  an  increase  in  the  number  of  fruits,  but  they  are  smaller.  This 
tendency  is  said  to  have  been  practically  applied  by  Von  Mons  to 
the  raising  of  apples,  in  order  to  check  too  vigorous  growth  and  to 
increase  fruitfulness.  Plants  from  unripe  seed  have  the  advantage 
of  ripening  their  fruit  earlier.  It  was  pointed  out  by  Goodale,  in 
1885,  and  since  by  Goff,  that  some  early  market  varieties  of  vege- 
tables indicate  that  they  have  been  originated  through  the  use  of 
green  seed. 
J.  W.  Toumey,  Botanical  Gazette,  August, 
Vegetal  Disseini-   p         calls  attention  to  the  persistence  with 
nation  in  the        .  .  ,    .         .  ,  .         .  _    _  .  , 
Genus  Opuntia.    wmcn  these  plants  retain  moisture.    A  thick 
epidermis,  with  small  sunken  stomata  and 
evaporating  surface  reduced  to  a  minimum  by  their  condensed  form, 
enables  them  to  remain  green  for  months,  even  when  exposed  to 
the  dry  and  scorching  heat  from  the  southwestern  plains.  Half  of 
one  of  the  segments  of  O.  basilaris  placed  in  a  small  box,  without 
either  soil  or  moisture,  produced  a  slender  branch  51^  inches  long, 
having  lost  only  1 5  per  cent,  of  its  total  weight  in  that  time.  This 
branch  subsequently  developed  a  second  branch  for  about  2  inches 
in  length  before  drying  up.    If  these  segments  fall  to  the  ground 
