422 
Gelsemium  Sempervirens,  Ait. 
( Am.  Jour.  Pharm. 
I  September,  1899. 
Cocculus  Indicus,  Linum, 
Colchicum  Root,  Lycopodium, 
Colchicum  Seed,  Mezereum, 
Colocynth,  Nux  Vomica, 
Gamboge,  Pareira, 
Geranium,  Pepo, 
Rubus,  Xauthoxylum, 
Sassafras  Pith, 
Squill,  Tea. 
Sweet  Almond, 
Sinapis  Alba  and  Nigra  (when  dry), 
Tamarind, 
THE  STRUCTURE  AND  DEVELOPMENT  OF  INTERNAL 
PHLOEM  IN  GELSEMIUM  SEMPERVIRENS,  AIT.1 
The  following  is  the  result  of  observations  made  during  the 
winter  of  1897-98,  in  the  Botanical  Laboratories  of  the  Biological 
Department  of  the  University  of  Pennsylvania.  The  material  used 
consisted  of  specimens  of  varying  age,  preserved  in  alcohol,  which 
had  been  collected  by  Professor  Macfarlane,  while  on  a  trip  to  Wil- 
mington, N.  C,  and  of  seedlings  grown  in  the  greenhouses  of  the 
department  from  seeds  collected  by  him.  An  abstract  of  the  ob- 
servations upon  the  stem  was  read  at  the  meeting  of  the  "  Society 
for  Plant  Morphology  and  Physiology,"  held  at  Ithaca,  N.  Y>,  in 
December,  1897. 
In  the  early  years  of  the  present  century  much  confusion  existed 
in  regard  to  the  terms  "for  the  softer  elements  of  a  vascular  bundle. 
These  were  variously  called  bast  fibres,  bast  cells,  latticed  cells,  sieve 
fibres,  etc.  Hartig,  in  1837,  was  the  first  to  correctly  describe  such 
elements  as  sieve  tubes,  and  to  regard  them  as  the  essential  constitu- 
ents of  the  phloem.  Several  years  later,  Hartig's  observations  were 
confirmed  by  von  Mohl,  Nageli  and  Hanstein.  The  investigation  of 
plants  with  internal  phloem,  or  phloem  on  the  inner  margin  of  the 
wood,  was  begun  by  Hartig  in  1854,  and  continued  by  others.  The 
orders  Cucurbitaceae,  Asclepiadaceae  and  Apocynaceae  were  among 
the  first  to  be  studied.  In  1875  de  Bary  originated  the  term  "  bi- 
collateral  bundle,"  a  name  that  has  been  objected  to  by  many  of  the 
later  workers.  From  that  time  onward  the  number  of  investiga- 
tors and  the  detail  with  which  the  work  has  been  carried  out  have 
steadily  increased.    The  most  important  contributions  to  the  litera- 
1  "  Transactions  and  Proceedings  of  the  Botanical  Society  of  Pennsylvania," 
Vol.  I,  No.  1. 
By  Caroline  B.  Thompson,  B.S. 
GENERAL  LITERATURE. 
