2  SMITHSONIAN    MISCELLANEOUS    COLLECTIONS  VOL.    96 
the  question  as  to  what  differences,  if  any,  may  occur  in  the  length 
of  the  first  internode  when  the  seedHngs  are  subjected  to  different 
wave-length  bands  of  the  visible  spectrum. 
EXPERIMENTATION 
First  series  (with  Mazda  lamp).- — Two  Bausch  and  Lomb  quartz 
monochromators  were  set  up  in  tandem  to  obtain  the  desired  isolated 
regions  of  the  spectrum.  A  looo-lumen,  i.6-ampere  street-series 
lamp  served  as  the  light  source.  A  small  mirror  reflected  the  beam 
of  light  onto  the  young  plants.  The  intensity  was  adjusted  to  1,2 
ergs/cm"/sec.  at  the  position  of  the  seeds.  The  dry  seeds  with  the 
chaft'  removed  were  placed  on  a  moist  medium  in  a  moisture  chamber 
Fic.   I. — Diagram  showing  general  arrangement  of  monochromators  and 
position  of  seeds  on  "  germination  wick  "  in  moisture  chamber. 
and  allowed  to  remain  undisturbed  for  a  period  of  four  days.  The 
moist  medium  on  which  the  seeds  were  placed  was  filter  paper  satu- 
rated with  distilled  water.  This  system  was  used  for  the  first  16  experi- 
ments. It  was  not  always  possible  to  get  the  same  degree  of  moisture, 
and  certain  irregularities  in  germination  occurred.  This  system  was 
discarded  in  favor  of  one  in  which  the  Livingston  solid  wick  men- 
tioned by  Norem  (1936)  was  used.  These  porous  stone  pieces  were 
cut  I  inch  square  and  4.5  inches  long.  After  they  were  moistened  with 
distilled  water  a  piece  of  wet  filter  paper  was  wrapped  around  each. 
They  were  then  placed  in  a  moisture  dish  containing  about  |  inch  of 
water.  The  seeds  were  laid,  groove  side  down,  along  the  edge  with  the 
base  end  extending  slightly  over  the  edge.  The  roots  attached  them- 
selves to  the  filter  paper  and  grew  down  into  the  water.  After  the  first 
24  hours  in  darkness  they  were  irradiated  continually  for  three  days 
with  monochromatic  light.    (See  fig.  i.) 
