Am.  Jour.  Pharm.  1 
November,  19 19. 
Book  Reviews. 
763 
The  book  will  undoubtedly  find  a  ready  field  and  the  future  edi- 
tions, which  will  doubtless  be  found  necessary,  will  probably  be 
free  from  the  defects  which  usually  attend  the  production  of  the 
first  edition  of  such  a  work. 
C.  H.  LaW. 
Revision  of  the  North  American  Species  of  Xanthium.  By 
Charles  F.  Millspaugh  and  Earl  E.  Sheriff,  Field  Museum  of 
Natural  History,  Chicago.  Publication  204,  Botanical  Series, 
Vol.  IV,  No.  2. 
In  this  splendid  monograph  the  authors  have  apparently  settled 
numerous  matters  of  bibliography  attendant  upon  North  American 
species  of  Xanthium.  A  brief  history  of  the  work  done  on  these 
plants  by  several  investigators  is  first  given.  This  is  followed  by 
the  characteristics  of  the  genus  Xanthium,  a  key  to  the  identification 
of  the  species  considered,  and  the  characteristics  and  distribution  of 
twenty-one  species.  Accompanying  the  article  are  seven  clear  plates, 
four. of  which  depict  the  fruit  characters  of  numerous  species,  the 
remaining  three,  the  characteristics  of  the  fruiting  plants  of 
Xanthium  curvescens,  X.  calvum  and  X.  australe,  respectively. 
Heber  W.  Youngken. 
